4

Ethical Issues in Pediatric Drug Studies

One broad principle for the conduct of pediatric drug studies is that children should not be subjected to research that is not necessary to advance knowledge relevant to child health. Another is that children should not participate in studies that are designed or conducted in ways that predictably undermine their potential to yield such advances. In either situation, children may be exposed to more than minimal risk in research without the expectation of an advance in generalizable knowledge. Thus, shortcomings in the design or conduct of pediatric drug studies that are described elsewhere in this report have ethical implications. Moreover, it is important that the exclusivity incentive and associated profit potential provided by the Best Pharmaceuticals for Children Act (BPCA) be accompanied by clear expectations that pediatric studies undertaken under the act are needed, soundly designed and executed, and public in their results.

One element of the task for the Institute of Medicine (IOM) was to assess ethical issues presented by studies requested under BPCA or required under the Pediatric Research Equity Act (PREA). To put this task in context, this chapter briefly reviews the federal regulatory protections provided to child participants in research and describes the resources available in the Food and Drug Administration (FDA) to provide guidance on ethical questions related to pediatric studies. It then considers several specific ethical issues, including the public availability of information from clinical trials, the enrollment of healthy children in pharmacokinetic studies, and the use of placebo controls in pediatric trials.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 89
4 Ethical Issues in Pediatric Drug Studies O ne broad principle for the conduct of pediatric drug studies is that children should not be subjected to research that is not necessary to advance knowledge relevant to child health. Another is that children should not participate in studies that are designed or conducted in ways that predictably undermine their potential to yield such advances. In either situation, children may be exposed to more than minimal risk in research without the expectation of an advance in generalizable knowledge. Thus, shortcomings in the design or conduct of pediatric drug studies that are described elsewhere in this report have ethical implications. Moreover, it is important that the exclusivity incentive and associated profit potential provided by the Best Pharmaceuticals for Children Act (BPCA) be accom- panied by clear expectations that pediatric studies undertaken under the act are needed, soundly designed and executed, and public in their results. One element of the task for the Institute of Medicine (IOM) was to as- sess ethical issues presented by studies requested under BPCA or required under the Pediatric Research Equity Act (PREA). To put this task in con- text, this chapter briefly reviews the federal regulatory protections provided to child participants in research and describes the resources available in the Food and Drug Administration (FDA) to provide guidance on ethical ques- tions related to pediatric studies. It then considers several specific ethical issues, including the public availability of information from clinical trials, the enrollment of healthy children in pharmacokinetic studies, and the use of placebo controls in pediatric trials. 89

OCR for page 89
90 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN REGULATORY REQUIREMENTS FOR PROTECTION OF HUMAN RESEARCH PARTICIPANTS As described in Chapter 1, deaths and other harms resulting from the use of drugs not studied in children have underscored the need for policies that encourage or require the testing of drugs for safety and efficacy with pediatric use. Such testing comes with its own risks and associated debates about what constitutes an acceptable risk. For example, following a study of chloramphenicol and two other antibiotics in the late 1950s (see discus- sion in Chapter 2), trial investigators were criticized for failing to stop fur- ther administration of the drug after early evidence of excess fatality rates was collected in the chloramphenicol arms of the trial. The argument at the time was that continuation of the trial was necessary to provide convincing evidence that the drug was unsafe (Murphy, 2000). Such debates, as well as examples of ethical lapses in clinical and other research involving both adults and children, have contributed to the adoption of general protec- tions for all participants in clinical research and to the creation of special protections for children. General Protections The special protections for children in research function in the context of broader protections for all human research participants. Today, all clini- cal research regulated by FDA, regardless of source of funding and auspices, must meet certain ethical standards (21 CFR 50 and 56). FDA’s rules are similar but not identical to the regulations of the U.S. Department of Health and Human Services (HHS) that cover research conducted or funded by the department (45 CFR 46). FDA regulations require several determinations about possible research harms and benefits (Box 4-1). Although sponsors, investigators, and regu- lators also have responsibilities for weighing and minimizing risks, insti- tutional review boards (IRBs) are panels created under regulations for the explicit purpose of reviewing human research conducted or funded by HHS or regulated by FDA. The primary responsibility of IRBs is to protect the rights and welfare of human research participants. The responsibilities of sponsors under FDA regulations include select- ing qualified investigators and monitoring research conduct, for example, to confirm that investigators have secured approval of trials from the ap- propriate IRBs. As described in Chapter 3, sponsors must submit an Inves- tigational New Drug (IND) application before they can ship investigational drugs or biologics across state lines and begin human research. The IND process requires conformance with FDA regulations, and applications in- clude a signed statement (Form 1572) from investigators confirming that they will comply with these regulations (FDA, 2010b).

OCR for page 89
91 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES BOX 4-1 Determinations of Research Risks and Potential Benefits Required by FDA Regulations Are risks to research participants minimized by using procedures that are consis- tent with sound research design and that do not unnecessarily expose participants to risk and, whenever appropriate, by using procedures already being performed for diagnostic or treatment purposes? 21 CFR 56.111(a)(1) Are risks to participants reasonable in relation to anticipated benefits to partici- pants and to the importance of the knowledge reasonably anticipated from the research? 21 CFR 56.5111(a)(2) Is the selection of research participants equitable, taking into account the pur- poses of the research, its setting, and the special problems of research involving vulnerable populations, such as children? 21 CFR 56.111(a)(3) Are appropriate provisions for monitoring participant safety made? 21 CFR 56.111(a)(6) Are appropriate provisions for protecting participant privacy and confidentiality made? 21 CFR 56.111(a)(7) Does the research meet the regulatory criteria for studies involving children, including those requiring parental permission and, as appropriate, child assent? 21 CFR 50.51-50.54 SOURCE: Adapted from IOM (2004). In addition to the rules for the protection of research participants, FDA is concerned about the scientific and ethical integrity of data from clinical trials. For example, as described later in this chapter, the agency conducts routine audits of data integrity in clinical trials. FDA also has conflict-of-interest policies that are intended to protect the integrity of research from bias arising from the financial relationships of investigators. The policies require sponsors either to certify that investi- gators for studies submitted in support of FDA approval had no financial interest in the studied product or the sponsor (e.g., by holding company stock) or to report the financial interests disclosed by the investigators. FDA reviews any disclosures to assess whether the interests had the poten- tial to bias the findings of the research. A thorough discussion of conflict of interest in pediatric drug studies is beyond the scope of this report, but the financial significance of such studies not only to sponsors but also to many academic programs and investigators and to some community-based physicians does raise concerns about the potential for bias in the design, evaluation, and reporting of research.

OCR for page 89
92 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN Studies Conducted Outside the United States The IND application process is mandatory for studies conducted within the United States. For studies conducted outside the United States, sponsors may chose to conduct the study under an IND application. Alternatively, under regulations issued in 2008 (73 FR 22800), FDA may accept results from foreign studies not conducted under an IND ap- plication if the studies conform to the terms of good clinical practice specified by the International Committee on Harmonization (ICH, 1996). The regulations define good clinical practice as “a standard for the design, conduct, performance, monitoring, auditing, recording, analysis, and re- porting of clinical trials in a way that provides assurance that the data and reported results are credible and accurate and that the rights, safety, and well-being of trial subjects are protected, including review and approval by an independent ethics committee (IEC), and provided that FDA is able to validate the study data through an onsite inspection, if necessary” (21 CFR 312.120(a)(i)). The 2008 regulations replace earlier rules that specified that international trials conform to the standards of the Declaration of Helsinki. The amount of clinical research conducted outside the United States has grown substantially in the past several decades. An analysis of trials registered at ClinicalTrials.gov (a clinical trials registration database that is described further in Chapter 8) found that as of November 2007, one- third of Phase III trials sponsored by the 20 largest U.S. pharmaceutical companies were conducted entirely at foreign sites and the majority of ac- tual study sites were outside the United States (Glickman et al., 2009). An analysis of published reports of studies conducted for pediatric exclusivity from 1998 to 2007 found that 65 percent of the studies that reported study locations had at least one site outside the United States, 38 percent had at least one site in a developing/transition country, and 11 percent had no U.S. sites (Pasquali et al., 2010; see also Dunne et al., 2011a; Maldonado et al., 2011). The globalization of research has raised questions about the adequacy of FDA and sponsor oversight of foreign studies and the adequacy of protections for research participants in certain countries (see, e.g., NBAC, 2001, and OIG/HHS, 2001).1 These questions involve, among other is- sues, possible inadequate review for conflicts of interest and possible inap- propriate inducements for parents to permit their children’s participation in research. Another concern involves the ability of sponsors and lead 1 In one clinical review for the drug lamotrigen (Lamictal), the reviewer noted that many studies were in countries in which the FDA had little experience (Katz, 2009a). Concerns about data integrity led to extensive discussions with the sponsor about its site inspections and to requests that the sponsor conduct further data analyses, which FDA staff reviewed before concluding that reasonable explanations for discrepancies in data among sites existed.

OCR for page 89
93 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES investigators to monitor studies that involve very large numbers of widely dispersed trial sites. Drug studies conducted in other countries may also raise questions of fairness or justice. This may happen when research in developing countries exposes the research participants to risk but the primary future benefits of the knowledge gained will accrue to patients in wealthier countries because the new drugs will not be affordable in the countries where they were studied (NBAC, 2001; Glickman et al., 2009). Moreover, pharmaceutical research taken as a whole may neglect diseases that are common in poor countries and rare in wealthier countries, a reality that has prompted a variety of international initiatives to increase research on specific neglected diseases, such as malaria, leishmaniasis, and schistosomiasis (see, e.g., Hotez et al., 2007; USAID, 2009; and WHO, 2011b). In the studies assessed by the IOM committee, one specific ethical issue in a pediatric trial appeared to be related to shortcomings in the conduct of a trial at an international site. In that case, the clinical reviewer stated that efficacy data on the prevention of maternal transmission of HIV infection were not evaluated, in part because the trial protocol did not incorporate the accepted standard of care for these study participants (Ayalew, 2002). FDA did, however, approve the addition of pharmacokinetic and safety in- formation to the labeling of the products generated by the trial component that investigated treatment of HIV-exposed or infected neonates. This com- ponent had been the subject of a written request from FDA (Kweder, 1999). Equity in international research is an important and complicated ethical issue that could not be effectively considered in the context of this study or on the basis of the documents that the committee reviewed. Because children are a vulnerable population, particular vigilance is important to ensure the ethical conduct of international pediatric research. Special Protections for Children in Research Beyond the general protections described above, both HHS and FDA regulations establish special protections for child research participants that extend beyond those applicable to adults. (For HHS, the regulations are found at Subpart D of 45 CFR 46; for FDA, they are found at 21 CFR 50.) Although HHS first issued its regulations in 1983, FDA did not explicitly adopt the special protections until April 2001, as required by the Children’s Health Act of 2000 (PL 106-310). As summarized in Box 4-2, the FDA (and HHS) regulations define four categories of research involving children that IRBs can approve. As an example of how the regulations may limit studies that are permitted for adults, these definitions would preclude the participation of healthy children in pharmacokinetic studies that involve more than minimal risk.

OCR for page 89
94 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN BOX 4-2 Categories of Clinical Research Involving Children That Are Approvable Under 21 CFR 50 • linical investigations that involve not greater than minimal risk (50.51) C • linical investigations that involve greater than minimal risk but present the C prospect of direct benefit to individual subjects such that (a) the risk is justified by the anticipated benefit to the subjects and (b) the relation of the anticipated benefit to the risk is at least as favorable to the subjects as that presented by available alternative approaches (50.52) • linical investigations involving greater than minimal risk and no prospect of C direct benefit to individual subjects, but likely to yield generalizable knowledge about the subjects’ disorder or condition and (a) the risk represents a minor increase over minimal risk; (b) the intervention or procedure presents experi- ences to subjects that are reasonably commensurate with those inherent in their actual or expected medical, dental, psychological, social, or educational situations; and (c) the generalizable knowledge is of vital importance for the understanding or amelioration of the subjects’ disorder or condition (50.53) • linical investigations not otherwise approvable that present an opportunity C to understand, prevent, or alleviate a serious problem affecting the health or welfare of children as agreed to by the Institutional Review Board and the Commissioner of the FDA after consultation with a panel of experts (50.54) SOURCE: IOM (2004). Approvals of research involving children are also contingent on ad- equate provisions for parental permission for a child’s participation in research and, when appropriate, for the assent of that child to such par- ticipation. Under the regulations, “children” are individuals who are not of legal age to consent to research as defined in the laws of the jurisdiction in which the research is to be conducted. Despite some uncertainty and disagreement about the concept of assent and its meaningfulness in actual research settings when a child’s parents favor participation, a 2004 IOM report argued that it is desirable to involve children in research discussions and decisions—consistent with their maturity and psychological state. Do- ing so “respects their emerging maturity, helps them prepare for participa- tion in research, gives them an opportunity to express their concerns and objections, and, possibly, allows them to influence what happens to them” (IOM, 2004, p. 7). Research is limited but suggests that practices concern- ing assent vary in actual pediatric trials (see, e.g., Olechnowicz et al., 2002; Ungar et al., 2006).

OCR for page 89
95 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES Making decisions about the four categories of approvable pediatric research defined in the HHS and FDA regulations necessarily involves sub- jective judgments about the risks and potential benefits to children of clini- cal studies. What is minimal risk? What is a minor increase over minimal risk? Can data help inform judgments about risk? (See, e.g., Wendler et al., 2005; Nelson, 2010; Roth-Cline et al., 2011.) These and other questions have been the subjects of ongoing debate both generally and with respect to specific research protocols. The 2004 IOM report cited above made several recommendations about the interpretation of key concepts in the HHS and FDA regulations. In brief, it recommended that investigators and reviewers of research protocols should • interpret minimal risk in relation to the normal experiences of average, “ healthy, normal children” and “focus on the equivalence of potential harms or discomfort anticipated in research with the harms or discom- fort that average, healthy, normal children may encounter in their daily lives or experience in routine physical or psychological examinations or tests; • interpret minor increase over minimal risk to mean a slight increase in “ the potential for harms or discomfort beyond minimal risk” and “assess whether the research procedures or interventions present experiences that are commensurate with, that is, reasonably comparable to, experi- ences already familiar to the children being studied”; • consider the risk of harms or discomfort in relation to the ages of the “ children to be studied and assess the duration as well as the probability and magnitude of potential harms or discomfort in determining the level of risk”; and • nterpret condition to mean “a specific (or a set of specific) physical, i psychological, neurodevelopmental, or social characteristic(s) that an established body of scientific evidence or clinical knowledge has shown to negatively affect children’s health and well-being or to increase their risk of developing a health problem in the future.” (IOM, 2004, p. 17) In addition, in evaluating whether to approve research that involves a minor increase over minimal risk and no direct benefit to a child with a con- dition or disorder, IRBs should find that “the research is likely to generate vital knowledge about the children’s disorder or condition” (IOM, 2004, p. 18). The research should not “unjustly single out or burden any group of children for increased exposure to research risk on the basis of their social circumstances” (p. 17). In situations in which some research procedures have the prospect of direct benefit and others do not, then “the potential benefits from one component of the research should not be held to offset or justify the risks presented by another” (p. 17). The issue of excessive risk has arisen in the context of the one written

OCR for page 89
96 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN request for the pediatric study of an off-patent drug that was accepted by the sponsor (NICHD, 2008). Although the drug, lindane, was also on the BPCA priority list for the National Institutes of Health (NIH) (see Chapter 3), an NIH advisory group described it to be too toxic—on the basis of existing evidence—to be ethically studied in children (NICHD, 2003). The rationale for the request was that despite label warnings about its toxicity, the drug did have considerable pediatric use for scabies; thus, dosing and safety studies might yield information to guide this use. As far as the com- mittee is aware, the requested studies have not been undertaken. (One study registered at ClinicalTrials.gov describes a completed study of an alternative product that also included an assessment of the incidence of use of lindane [ClinicalTrials.gov identifier: NCT00604084].) FDA ORGANIZATIONAL RESOURCES TO SUPPORT ETHICAL STANDARDS IN PEDIATRIC RESEARCH FDA has developed generally available resources to promote ethical standards for studies undertaken to support approvals of medical products. It has also created resources specific to pediatric studies. The discussion in this section starts with the latter. Expertise in Pediatrics, Pediatric Research, and Research Ethics In 1999, FDA created a pediatric advisory subcommittee to its Anti- Infectives Advisory Committee. Among other issues, the subcommittee advised on ethical questions in pediatric studies. In 2004, as provided for by BPCA of 2002 and PREA of 2004, FDA created the publicly deliberat- ing Pediatric Advisory Committee (69 FR 46098). This committee, in turn, created a subcommittee on ethics that continues. Among other issues, the Pediatric Advisory Committee and its subcommittee may be asked to con- sider whether studies not otherwise approvable under 21 CFR 50 should be recommended for approval by the FDA Commissioner under Section 50.54 (FDA, 2006c).2 In addition to specific study proposals, the ethics subcommittee has also considered broader topics. One recent example is the status of clinical studies that might, in the future, involve the exploratory administration of subtherapeutic doses, or “microdoses” of investigational products to children (Nelson, 2011b). 2 The process is rarely used. One example that came before the FDA Commissioner in 2004 involved a proposed study that would have used magnetic resonance imaging to examine the effects of a single dose of dextroamphetamine versus placebo for attention deficit hyperactiv- ity disorder. It was recommended for approval by the Pediatric Advisory Committee but was withdrawn before final action (SACHRP, 2005).

OCR for page 89
97 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES In 2002, when Congress directed the creation of the Office of Pediatric Therapeutics at FDA, it specified that the office would have at least one person with “expertise concerning ethical issues presented by the conduct of clinical research in the pediatric population” (21 USC 393a). The Office of Pediatric Therapeutics currently includes two pediatric ethicists as well as other members with expertise in pediatrics. These resources are available to staff of the Center for Drug Evaluation and Research (CDER) and the Center for Biologics Evaluation and Research (CBER) as well as staff of the Center for Devices and Radiological Health (CDRH). In addition, the Pediatric and Maternal Health Staff within the Of- fice of New Drugs at CDER provides pediatric expertise to assist that center’s review divisions. At both CBER and CDER, approximately 15 to 20 percent of medical officers are pediatricians (personal communication, Catherine Lee, Office of Pediatric Therapeutics, FDA, November 21, 2011). Such expertise is relevant not only to the valid and reliable assessment of scientific questions but also to the assessment of age- and condition-specific risks required by the special protections for child research participants. As described in Chapter 3, in 2007 Congress provided for an internal FDA committee to review written requests and pediatric studies conducted under BPCA and to review pediatric plans, assessments, deferrals, and waivers under PREA (21 USC 355d). This review committee was to include expertise in pediatric ethics specifically as well as expertise in pediatrics, biopharmacology, statistics, chemistry, and legal issues. FDA created the Pe- diatric Review Committee (PeRC) to undertake the required reviews, which cover both scientific and ethical issues. These reviews frequently result in recommendations for significant changes in study plans, including recom- mendations for changes in inclusion criteria, additional adult or animal studies, or modifications in trial design to achieve an acceptable balance of risk and potential benefit (personal communication, Robert Nelson, Office of Pediatric Therapeutics, FDA, August 10, 2011). The agency can impose a clinical hold that delays or suspends work on studies that violate the regulations governing the protection of children in research. In addition to topics considered during committee or subcommittee meetings, issues may be brought to the FDA pediatric ethics staff for consultation. Such consultations have covered the ethical implications of many elements of pediatric drug studies, including the definition of the pediatric population to be studied, the choice of control group, the use of invasive placebos, the requirements for parental permission and child as- sent, the assessment of risk and benefit, the appropriate standard of care in international studies, and the planning of first-in-children studies (i.e., when a drug or an indication has not been previously studied in adults) (personal communication, Robert Nelson, Office of Pediatric Therapeutics, FDA, August 10, 2011). The consultations have involved a wide array of

OCR for page 89
98 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN specific product classes and clinical conditions, for example, long-acting beta-agonists; proton pump inhibitors in infants; antiretroviral products; growth hormones; monoclonal antibodies for respiratory syncytial virus and asthma; psychotropic medications; cognitive enhancers in Down syn- drome; and stem cell therapies for diabetes mellitus, cancer, autism, cerebral palsy, and spinal muscular atrophy. Some of the IOM committee’s assessments covered studies that were requested, required, and undertaken before the resources just described were in place. Although the committee could not reasonably assess the sufficiency of past or current pediatric expertise across CDER and CBER review divisions and in the Office of the Commissioner, this report empha- sizes that such expertise is critical to the design, conduct, and evaluation of scientifically and ethically sound pediatric drug studies. Other Resources Relevant to Research Integrity Among other resources, FDA has developed a number of guidance or draft guidance documents on ethics and integrity in FDA-regulated trials, including guidance for IRBs and investigators about FDA policies and ex- pectations (FDA, 2010b). The infrastructure to support the ethical conduct of research also includes the Office of Good Clinical Practices in the Office of the FDA Commissioner. This unit, among other responsibilities, admin- isters FDA’s Human Subject Protection/Bioresearch Monitoring Council. Within CDER, the Division of Scientific Investigations (DSI) is respon- sible for verifying the “integrity of efficacy and safety data submitted to the FDA in support of new drug applications [NDAs] and to assure that the rights and welfare of human research subjects are protected” (FDA Regulatory Procedure Manual at 1-4-5; see also FDA, 2009a). (For CBER, the equivalent office is the Division of Inspections and Surveillance.) The division engages both in routine audits of data integrity in clinical trials as part of the review of NDAs and in investigations of specific complaints about the conduct of trials, including complaints about the protection of research participants. Among other tasks, a routine inspection might verify that investigators secured IRB approval(s) and parental permission. It might compare sites at which investigators have financial interests in the outcome of the trial (e.g., because they hold stock in the sponsor company) with other sites for indications that financial interests have influenced reported results. When an audit cites violations of protocols or good clinical practice, an FDA reviewer may assess these violations to determine whether they could affect study findings. The reviewer may then disallow acceptance of certain data in support of applications. If a DSI or other investigation casts doubt on the efficacy or safety find- ings of a sponsor’s trial of a product with adults, then the use of data from

OCR for page 89
99 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES that trial as a basis for starting pediatric trials may also be cast into doubt. An example involves the drug telithromycin (Ketek), which was approved in 2004 for treatment of certain forms of acute bacterial exacerbations of chronic bronchitis, acute bacterial sinusitis, and community-acquired pneumonia; the approval specified required pediatric studies of the last two indications (Goldberger, 2004). After public disclosure of significant irregularities in a key clinical trial and questions about FDA management procedures, FDA withdrew approval for the first two indications in 2007 (Ball, 2007; Ross, 2007; see also Soreth et al., 2007). Subsequently, after public questions about the safety of pediatric studies involving the drug but also after several studies were completed, the company halted pediatric studies (Ault, 2006; Harris, 2006). ETHICAL ISSUES IN STUDIES CONDUCTED UNDER BPCA AND PREA An overarching ethical question for pediatric studies is whether the ex- pected benefit of the knowledge to be gained from the research is reasonable in relation to the potential risk to child participants. This can sometimes be difficult to assess, particularly many years after the studies were conducted when the uncertainties of an earlier time may have diminished as knowledge about benefits and harms has accumulated from different sources. During its assessments of ethical issues in studies requested and required under BPCA and PREA, the committee primarily relied on the information in clinical, clinical pharmacology, and statistical reviews prepared by FDA staff. Staff reviewers have access to the voluminous submissions of spon- sor data, the record of communications between sponsors and FDA about the design and conduct of the pediatric studies, and the reports from DSI. Except for egregious problems, the reviews and the information on which they are based are unlikely to allow assessments of certain aspects of the ethical conduct of research. These aspects include the soundness of processes for obtaining parental permission and child assent to research participation, the nature and risks of incentives offered for clinician par- ticipation (e.g., payments per child enrollee in office-based studies), and the extent and appropriateness of incentives offered to parents and children (e.g., payments for time and inconvenience and provision of gifts). The IOM committee did not search the literature to determine whether others had raised questions about the ethical status of particular studies requested under BPCA or required under PREA, although committee members were sometimes aware of such questions. In addition to examples drawn from the committee’s assessments, this discussion also cites other cases that il- lustrate ethical questions or concerns with studies conducted under BPCA and PREA.

OCR for page 89
100 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN The first issue that the committee identified involves transparency in the form of public access to information from requested or required pedi- atric studies. The following discussion also describes issues of integrity or ethics that clinical reviewers have identified and notes concerns about the participation of healthy children in pharmacokinetic studies and the use of placebo-controlled trials. Transparency, Labeling, and Dissemination Transparency in the form of public access to information generated by studies requested under BPCA or required under PREA has ethical as well as scientific implications. Provisions for such access recognize and respect the contributions that children (and parents) make by participating in re- search, acknowledge these research results as a public benefit, and support the accountability of sponsors and FDA for their actions and decisions. As described in Chapter 3, in the reauthorization of BPCA and PREA in 2007, Congress required that the results of studies requested under BPCA or required under PREA be reflected in labeling changes in most cases. It also required FDA to make public the staff clinical, clinical pharmacol- ogy, and statistical reviews associated with requested or required studies in a timely way and to make written requests public following exclusivity determinations. Before these changes, BPCA of 2002 required posting of brief summaries of product reviews for studies requested under BPCA, but the requirement did not apply to studies required under PREA. FDA does make available some information about adult studies through Drugs@FDA. Such information, especially for studies submitted in supplemental NDAs or Biologics License Applications (BLAs) following a drug’s initial approval, is not as extensive as that required for pediatric studies, and it can be more difficult to find (O’Connor, 2009). The public information requirements of the 2007 legislation did not apply retroactively. Thus, information about studies requested under BPCA and, even more so, studies required under PREA is still restricted for prod- ucts with study assessments or exclusivity determinations made before the 2007 reauthorizations. Information can be requested under the Freedom of Information Act (FOIA), but that process is typically time-consuming and burdensome. Whether they are related to FOIA requests or not, many of the FDA documents consulted during the preparation of this report had signifi- cant redactions in ethically sensitive sections of clinical reviews, including overall risk-benefit assessments (see discussion in Chapter 5). Although FDA agreed to provide the committee with redacted requests and reviews for up to 50 products with labeling changes prior to September 27, 2007, the release of such documents for some products with exclusivity but no labeling changes could occur only with the permission of the spon-

OCR for page 89
101 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES sor. As discussed in Chapter 6, both of the sponsors of neonatal studies of bacterial conjunctivitis for which no information was added to the label but for which exclusivity was granted in 2003 refused to provide permis- sion. Substantial numbers of babies were studied in these trials, but that exposure has contributed only brief FDA summaries of study results to the public record at FDA. In addition, FDA is still limited in what it can disclose about studies that have not had results submitted in connection with an NDA or BLA, for example, when sponsors have abandoned clinical development of a drug. One serious documented instance of this involves the drug cisapride (Propulsid), which was withdrawn from the market in 2000 (Willman, 2000; Harris and Koli, 2005). This withdrawal came some years after FDA first became concerned about the drug’s risks, including its risks to children. It likewise came some years after the agency knew of sponsor trials (which had not been submitted) that showed a lack of efficacy in children. At the time that the drug was withdrawn, a spokesman for a children’s hospital at which a child had died during a clinical trial of the drug said the drug “has been widely prescribed by pediatricians and pediatric specialists for the treatment of gastroesophageal reflux in children and infants due to its efficacy and presumed safety based on the adult data” (Neergaard, 2000). Citing ethical obligations, some have called for the creation of a publicly accessible database of results of abandoned trials (Rogawski and Federoff, 2011). In addition to these issues of transparency, another concern involves the appearance in the published literature of information that appears to be inconsistent with the assessments of FDA reviewers and information in a product’s label. A study by Benjamin and colleagues reported an analysis of 129 of 137 BPCA-related labeling changes that occurred by September 2007 (Benjamin et al., 2009). As summarized by the authors, Thirty-three products (26%) had pediatric safety information added to the labeling. Of these, 12 products had neuropsychiatric safety findings, and 21 had other important safety findings. Only 16/33 (48%) of these trials were reported in the peer reviewed literature; however, 7/16 of these pub- lications focused on findings substantively different from those highlighted in the FDA reviews and labeling changes. (p. 180) For studies leading to pediatric exclusivity, the authors suggest the need for a mechanism to increase the dissemination of unbiased informa- tion based on these studies (see also Benjamin et al., 2006). Given concerns that physicians do not generally read the study details or other information in drug labels and more general concerns about selective publication by sponsors, such unbiased dissemination could increase clinician awareness of important safety and efficacy findings (see Appendix B).

OCR for page 89
102 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN In this context, it should be noted that FDA reviews of pediatric and adult studies—even those that are public—are not integrated into resources such as PubMed and ClinicalTrials.gov. Thus, these evaluations may not be identified and incorporated into evidence-based reviews of clini- cal therapeutics. FDA Reviewer Comments on Study Integrity and Ethics Particularly in recent years, FDA clinical reviews of sponsor applica- tions have included sections that variously comment on study integrity, ethics and good clinical practices, and financial disclosures or conflicts of interest. In these sections, reviewers may discuss protocol violations, spon- sor affirmations about compliance with ethical principles or good clinical practices (which should subsume compliance with regulatory protections for children), and sponsor certifications about investigator financial rela- tionships or conflicts of interest. In general, in the clinical reviews that included sections on data integ- rity, financial disclosures, or ethics (with minimal redactions), the commit- tee identified no major ethical issues based on the reviewers’ assessments. Particularly for more recent reviews, these sections of the reviews did docu- ment FDA attention to the issues, which potentially reinforces adherence to standards for scientifically and ethically sound investigations. Early reviews examined by the committee omitted mention of these issues more often than recent reviews. In some cases, the committee found that review sections related to issues of study integrity had been redacted (see, e.g., Bastings, 2002). In addition, most specific information about investigator financial relationships or conflicts of interest was redacted. A clinical review may make clear that the reviewer was relying pri- marily on the statements and certifications of the sponsor. For example, “[t]he applicant states that the quality of study data was assured through monitoring of investigational sites, appropriate training of study personnel, independent audits, investigational site visits, and periodic data source veri- fication” (Roman, 2007, p. 14). Similarly, “the [sponsor’s] clinical overview states that the studies were conducted in compliance with ethical principles that have their origin in the Declarations of Helsinki and in accordance with the International Conference on Harmonization (ICH) E6 Guideline for Good Clinical Practice (GCP)” (Xiao, 2009, p. 14). If sponsor disclosures or onsite audits identify issues, reviews may as- sess whether the situation (e.g., a protocol violation or a financial relation- ship with the sponsor) could be expected to influence study findings. For example, in connection with an application submitting requested studies of valganciclovir hydrochloride (Valcyte), DSI’s routine, onsite investiga- tions found a number of protocol violations. In the clinical pharmacology

OCR for page 89
103 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES review, the reviewers discussed each type of violation and determined that some information submitted by the sponsor could not be accepted but that other protocol violations would not be expected to affect conclusions (Krudys and Arya, 2008). After additional information was submitted, FDA approved the drug for prevention of cytomegalovirus (CMV) disease in children age 4 months or over who received kidney or heart transplants and were at high risk for developing the disease.3 Pharmacokinetic Studies with Healthy Children As described in Chapter 2, pharmacokinetic studies undertaken with children typically differ from those undertaken with adults. For adults, Phase I studies often start with a small number of healthy volunteers. The studies seek to investigate a drug’s pharmacokinetics in individuals not af- fected by a disease under study; therefore, they offer no prospect of medical benefit to these volunteers. For children, if either the drug or the research procedures (e.g., extensive blood draws), or both, are deemed to involve more than minimal risk without the prospect of direct benefit to the child, then the regulatory framework outlined earlier precludes the enrollment of healthy children in such studies. Alternatives to such studies might involve pharmacokinetic studies of children with the condition under investigation or pharmacokinetic studies undertaken as part of an efficacy and safety trial. Although most pediatric pharmacokinetic studies do not include healthy children, exceptions exist. For example, for a pharmacokinetic study of almotriptan (Axert), investigators recruited what were described to be healthy adolescent and adult subjects, with or without a history of migraine; of the adolescents recruited, only 2 of the 18 had a history of the condition (Harris, 2009). The original written request for a study of this drug specified a study of adolescents with a history of migraine (Behrman, 2001a); the clinical and clinical pharmacology reviews did not comment on the inclusion of adolescents without a history of migraine. The clinical review noted that the triptan drugs are generally considered to be safe but also noted concerns about cardiac and other risks. As presented for IRB review, the study protocol should have been clear that healthy children could be recruited for the pharmacokinetic study and the review should 3 As amended, the written request (which derived from a sponsor proposal) sought pharma- cokinetic and safety studies but not efficacy studies for three categories of transplant patients and a pharmacokinetic and safety study for neonates with congenital CMV disease (Pikis, 2009). Because the latter condition does not occur in adults, the clinical review explained that efficacy could not be extrapolated and, thus, that FDA could not approve use of the drug for that indication.

OCR for page 89
104 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN have considered whether such a study presented no more than minimal risk to healthy children.4 Use of Placebo-Controlled Pediatric Trials The use (and nonuse) of placebo controls may present ethical ques- tions in both pediatric and adult clinical trials, and ethicists, governments, investigators, and others have sought to provide principles to guide the use of such controls. For example, the Declaration of Helsinki, as amended, states: The benefits, risks, burdens and effectiveness of a new intervention must be tested against those of the best current proven intervention, except in the following circumstances: • he use of placebo, or no treatment, is acceptable in studies where no T current proven intervention exists; or • here for compelling and scientifically sound methodological reasons W the use of placebo is necessary to determine the efficacy or safety of an intervention and the patients who receive placebo or no treatment will not be subject to any risk of serious or irreversible harm. Extreme care must be taken to avoid abuse of this option. (WMA, 2008, p. 5) What constitutes compelling and scientifically sound reasons for the use of placebos in adult trials is a subject of debate (see, e.g., Temple and Ellenberg, 2000; Miller and Shorr, 2002; and Temple and Meyer, 2003). FDA no longer specifies adherence to the declaration as a standard for in- ternational clinical trials (73 FR 22800). Rather, studies are to be conducted consistent with the good clinical practice standards cited earlier. Because children are a vulnerable population and because many chal- lenges surround parental permission and child assent for a child’s participa- tion in research, particular caution is needed when placebos are employed in pediatric trials. When the use of a placebo control in a pediatric clinical trial is proposed or contemplated, several questions warrant consideration. 4 Other historical examples of pharmacokinetic studies with healthy children can be cited. FDA has accepted pharmacokinetic studies of cold medicine combination products (ibuprofen and pseudoephedrine hydrochloride) that enrolled healthy children (ages 4 to 11 years in one study [Adebowale, 1999] and ages 6 to 11 years in the other [Adebowale, 2002]). One justifi- cation for such studies is that it is healthy children who get colds and whose parents may then treat them with these products. To cite another example of healthy children in pharmacoki- netic studies, at the time that it was approved in 1998, the antibiotic rifapentine (Priftin) had labeling that described the results of a pharmacokinetic study with healthy volunteers ages 12 to 15 years that yielded results similar to those found for adults (Sanofi-Aventis, 2009). See also Marshall et al. (1999) (abstract).

OCR for page 89
105 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES • Is the condition to be studied one for which one or more therapies have been demonstrated to be safe and effective in the pediatric age group to be studied? In these cases, comparative effectiveness, superiority, or inferiority trials may be more appropriate than placebo-controlled studies. • What would be the expected harm of forgoing the use of such an existing therapy and using a placebo instead, taking into account what is known about the safety and efficacy of that therapy? Omis- sion of a proven treatment may harm a child, so investigators and IRBs must ask whether that harm involves no more than a minor increase over minimal risk. • Does the study design require that children who are currently re- ceiving an effective therapy have that therapy withdrawn, or is the placebo to be used concurrently with such a therapy in one arm of the trial? In the written requests and studies that were reviewed for this report, placebo-controlled trials of efficacy were fairly common. For example, among the sample of 45 labeling changes that the committee assessed,5 tri- als with both an active comparator and a placebo control were undertaken for 3 products, at least one placebo (only)–controlled trial was performed for 22 products, and active comparators (only) were used for 7 products. For the remaining labeling changes, situations varied, involving, for ex- ample, FDA acceptance of extrapolation of efficacy from adult studies with no requirement for a controlled trial of efficacy. The conditions investigated in active comparator-controlled trials in- cluded, in some cases, conditions that were also studied in placebo-con- trolled trials, for example, asthma and osteogenesis imperfecta. Other conditions studied with active comparators included certain bacterial infec- tions and Kawasaki disease. FDA has not necessarily approved the com- parator drugs for pediatric use. Examples, discussed in Chapter 6, include requested studies of bacterial conjunctivitis in neonates. The conditions studied in placebo-controlled pediatric trials included asthma, anxiety, hypertension, schizophrenia, mania associated with bipolar disorder, migraine, osteogenesis imperfecta, attention deficit hyperactivity disorder, and juvenile rheumatoid arthritis. At the time of some of the placebo-controlled trials, no treatments had been approved by FDA (for the pediatric age group studied) for the condition under study (e.g., irrita- bility associated with autism). The use of placebo controls in these studies does not create the potential for harm by depriving a child of a therapy 5 See Appendix A for a description of how the committee selected its sample.

OCR for page 89
106 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN demonstrated (or widely thought) to be effective and thus does not raise ethical concerns. In other cases, effective treatments were approved and children were taken off effective treatments. For example, effective treatments for asthma were available at the time that some of the pediatric placebo-controlled trials were undertaken.6 A review published in 2004 examined rates of exacerbation and related participant withdrawal from trials in 45 placebo- controlled trials that did not specify the use of anti-inflammatory drugs in all those participating (Coffey et al., 2004). The review concluded that withdrawals and exacerbations were more frequent in the placebo groups. Of the 45 trials, 14 enrolled only children; the other 31 included both adults and children. The child-only trials showed the same pattern of higher num- bers of withdrawals and exacerbations in the placebo groups. Subgroup analyses were not reported for the children in trials that combined adults and children. This omission of subgroup analyses by age—and, thus, the omission of child-specific data—also raises ethical concerns. As the authors of the review observe, children in these studies were “being exposed to the risks and harms of research, but there is no advance in pediatric medicine from their participation” (Coffey et al., 2004, p. 91). In pediatric hypertension, another condition for which effective treat- ments (e.g., diuretics) were available at the time of placebo-controlled pe- diatric studies, investigators examined adverse events and serious adverse events in 10 placebo-controlled efficacy trials of drugs for hypertension (Benjamin et al., 2008). In this case, they found no difference in the rates of occurrence of such events between the children receiving the placebo and those receiving the study drug. Some alternatives to the placebo-controlled trial raise their own ques- tions. For example, in a noninferiority trial comparing the test drug and an active comparator, one question is, what can be appropriately assumed about the effect of the comparator drug? Randomized withdrawal designs also have disadvantages. The committee discussed issues with these and other trial designs but concluded that a systematic ethical review was not feasible given the complexity of (and disputes about) the issues and the scope of the committee’s other tasks. 6 In 1991, the National Heart, Lung, and Blood Institute issued guidelines that advised that anti-inflammatory medications be used for both children and adults who had more than mild asthma (NHLBI, 1991); updates followed in 1997 and 2004 and most recently in 2007 (NHLBI, 2007).

OCR for page 89
107 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES Ethical Aspects of Pediatric Exclusivity The committee was not asked to examine the ethical implications of the incentives for pediatric studies provided by BPCA, but these implica- tions, including questions of intergenerational justice, do need attention. It may be argued, on the one hand, that studies conducted in response to the exclusivity incentive for pediatric studies, first, offer justice to the youngest members of society and, second, provide some balance both to usual market forces that favor studies with adults and to federal programs such as Social Security and Medicare. (For a discussion of generational fairness issues and federal policies, see, for example, Newacheck and Benjamin, 2004.) On the other hand, some have cited costs to older members of society associated with the delayed entrance of generic competitors associated with the extra 6 months of marketing protection offered by pediatric exclusivity. For example, Dor and colleagues (2007) noted that although “evidence sug- gests value in reauthorizing BPCA, significant concerns have been raised over the cost to both the federal government and consumers regarding the length of time (currently 6 months) of the market exclusivity extension” (p. 7). Medicare, Medicaid, and private health insurance plans (and, thus, taxpayers or premium payers) pay some of the costs of higher drug prices, and some are paid by patients. Some analyses have attempted to estimate the economic benefit to sponsors of pediatric exclusivity. In an analysis involving nine drugs for hypertension, Baker-Smith and colleagues (2008) reported that the median cost to complete pharmacokinetic studies was $862,000 and that the me- dian cost to complete safety and efficacy trials was $4.3 million. Taking the after-tax sales into account for the 6 months of additional marketing protection, they reported that the ratio of net economic return to study cost was strongly positive but also quite variable (average return of 17 to 1 with a range from 4 to nearly 65). In another study that examined nine representative products for which sponsors received exclusivity, Li and colleagues (2007) estimated that the median net benefit from the existing exclusivity period of 6 months was $134,265,456, with a range of a negative $8,946,033 to a positive $507,899,374. (The authors noted limitations of information about the cost to sponsors of conducting trials.) Although generally favorable about the benefits of BPCA, the authors concluded that the pediatric exclusivity incentive of BPCA “overcompensates blockbuster products for performing clinical trials in children while other products have more modest returns on investment under this program” (p. 487). Both the studies cited above relied on detailed data from sponsor sub- missions to FDA that are not public (e.g., data on specific lab tests, study site visits, screening of potential participants, and regulatory audits among

OCR for page 89
108 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN other variables). For these analyses, FDA allowed investigators who were special government employees to have access to data that were stripped of personal identifiers such as investigator names but otherwise not redacted. Before the 2007 reauthorization of BPCA, some requested studies led to the granting of pediatric exclusivity without labeling changes and with- out public access to the clinical and other reviews of the studies. Sponsors obtained the reward of exclusivity with little or no information benefit to clinicians, child patients, or the public. In 2007, Congress sought to correct this situation by requiring that information from studies conducted under BPCA be included in the label and that clinical and other reviews be posted (see Chapter 3). Nonetheless, instances still occur in which sponsors are granted exclusivity without a labeling change (see the discussion of bival- rudin and gatifloxacin in Chapter 7). Another issue with studies requested under BPCA is the extent to which value can be obtained from a fifth or sixth request for pediatric studies of drugs in the same class and with the same mechanism of action as previ- ously investigated drugs. Because most written requests are not public7 and because FDA cannot make information about INDs public, it is not possible to identify comprehensively requests that involve the same class of drug, the same indication, all or some of the same types of studies, and all or some of the same age groups. Multiple studies are a particular concern when they consistently show a lack of efficacy. Chapter 6 describes several such situations with studies with newborns. One question is whether there was a point at which suf- ficient information showing a lack of efficacy had been submitted that the benefit anticipated from continuing the studies (e.g., data on pharmaco- kinetics to guide persisting off-label use) no longer justified the risks and economic costs. CONCLUSIONS A number of national and international standards are in place to pre- vent unethical clinical studies in general and with children specifically. They include the FDA and HHS regulations, the system of research review and monitoring that these regulations have helped create, and various programs of ethics education for regulators, investigators, sponsors, and IRBs. The provisions made by Congress for FDA to add expertise in pediatrics and pediatric research ethics offer additional protections to children. Still, an ethical tension may exist in pediatric drug studies and, indeed, 7 As of February 1, 2012, and as required by FDAAA, FDA had posted 47 written requests (with amendments) at http://www.fda.gov/Drugs/DevelopmentApprovalProcess/Development Resources/ucm049997.htm.

OCR for page 89
109 ETHICAL ISSUES IN PEDIATRIC DRUG STUDIES clinical research generally. That is, depending on the specifics of a research situation, investigators in pediatric studies may face a conflict between the best interest of an individual child as a potential research participant and the interests of future children who might benefit from the research. Spe- cial safeguards help protect child participants in research, but they do not eliminate the tension. Likewise, although regulations and research ethics programs are valuable, they do not substitute for sponsors, investigators, and FDA staff who—beginning with the earliest stages of study planning through its completion, evaluation, and dissemination—understand and follow ethical and scientific standards for pediatric research. The committee was not asked to assess the benefits of BPCA and PREA in relation to their costs. Such a policy evaluation would be complicated and require many assumptions in the absence of evidence to support state- ments about causation. To help provide information for a narrower assess- ment of the costs incurred and benefits accrued by sponsors of pediatric studies requested under BPCA, Congress or FDA could support additional analyses similar to those cited earlier in this chapter. Relying primarily on FDA clinical reviews, the committee identified some concerns about pediatric studies conducted under BPCA and PREA. One concern involves placebo-controlled trials. Such trials do not necessar- ily present problems, but it is important that protocols for such studies be consistent with ethical and scientific standards. The committee suggests that FDA document the scientific and ethical rationales for the use of placebo- controlled pediatric trials, first, in written requests that include such studies and, second, in clinical reviews prepared by FDA staff. Such documenta- tion, particularly in cases in which effective alternative treatments exist, could help clarify whether the research will meet or has met the ethical standards described earlier in this chapter. Justification should also be con- sidered in some other situations, for example, when FDA accepts the use of an unapproved drug as the active comparator in a controlled trial or to the inclusion of healthy children in pharmacokinetic studies. Another concern that the committee identified is some continuing limi- tations on public access to information from studies conducted under BPCA and PREA. Despite substantial improvements for recently submitted stud- ies, access issues continue for clinical and other reviews for older NDA and BLA submissions. Redactions of significant sections of clinical reviews also present concerns. Congress and FDA have several options to further expand access to information from pediatric studies. One is for Congress to direct that FDA make public the clinical and other reviews of drugs and biologics approved before September 27, 2007. An additional option is for Congress to direct the Government Accountability Office or other entity independent of FDA to analyze the use of redactions for reviews of pediatric studies. The task

OCR for page 89
110 SAFE AND EFFECTIVE MEDICINES FOR CHILDREN would be to assess whether redactions exceed what is necessary to protect confidential commercial information and trade secrets and critical aspects of FDA’s internal deliberations. A further step would be for FDA to explore with the National Library of Medicine how clinical and other reviews might be made accessible through PubMed and through links to trials registered at ClinicalTrials.gov. Such integration could provide an independent as- sessment to supplement sponsor summaries and publications. To obtain a better understanding of the dissemination of information, FDA could seek an assessment of private sector dissemination of findings from pediatric studies and labeling changes conducted under BPCA and PREA, including both the speed of dissemination and the accuracy and completeness of the information as disseminated. The committee recognizes FDA’s limited resources. At the same time, it is concerned that rationales for ethically sensitive decisions be clear and also that the public have access to information in which sponsors, investigators, research participants, taxpayers and premium payers, and FDA staff have already invested—in different ways—considerable expense or effort.