The committee has no comprehensive information on the extent to which orphan drugs are approved with postmarketing study requirements or commitments or with REMS requirements. Later in this chapter, Box 3-3 includes examples of orphan drugs approved with postmarketing study provisions.
In response to 1996 and subsequent legislation, CDER has begun to post information on the basis for its judgments about new drugs, including those approved as orphan drugs. These descriptions include assessments by agency reviewers of the quality and results of the clinical trials submitted to support approval. Information from these reviews is presented in the next section of this chapter to illustrate the range of evidence that FDA may accept in particular cases. FDA now also makes available online the staff reviews and company presentations provided to its expert advisory committees when those groups have been asked for advice on a product application. Transcripts of the meetings may provide further information, for example, in responses to questions about the materials submitted. Staff analyses (and associated discussion) may also be available for drugs that are considered during an advisory committee meeting. Reviews for generic drugs are generally not publicly available.4
Notwithstanding FDA actions to provide more details about the basis for its approval of a new drug, many details about drug trials are treated as confidential and not made public by FDA. As discussed in Chapter 5,
For example, in 2009, FDA approved generic chenodeoxycholic acid as an orphan drug for the treatment of gallstones. The drug was approved for this indication in 1983 as one of the first orphan drugs but was subsequently withdrawn from the market. A summary of the 2009 FDA review, including any data on the safety and effectiveness generated since 1983, is not public, although it might be obtained eventually through an inquiry under the Freedom of Information Act. In 2004 and 2007, different companies received orphan drug designations for the drug’s use to treat cerebrotendinous xanthomatosis (CTX). (Orphan drugs designations and approvals are found at http://www.accessdata.fda.gov/scripts/opdlisting/oopd/index.cfm.) Advocates for patients with CTX noted the effort invested in obtaining the 2009 FDA approval (but did not note that the approval was for gallstones) and emphasized that the company distributing the drug “has committed to ensuring that all CTX patients will have access” to the drug through a specialty pharmacy (CTXinfo.org, 2010). That company received a new orphan designation in 2010 for the CTX indication.