This is the second in a series of blog posts VOI Consulting will publish based on high-level examination of the company’s new insiteinvestigator™ database. It addresses FDA approval requirements for cancer drugs approved between 2005 and 2011.
As a rule, the FDA recommends that applications include data from “at least two adequate and well-controlled clinical trials” as a condition of standard drug approval. In cancer, however, the high degree of unmet medical need and the urgency of offering new treatments for potentially fatal diseases mean that approvals are based on a wide range of clinical data packages.This is demonstrated in Figure 1 which shows that the “two adequate and well-controlled trials” standard is actually an unusual occurrence in cancer as only 2% of all indications received approval using this approach. Indeed, approved applications have been based on pivotal trials ranging from as little as a single Phase I pharmacokinetic study (asparaginase Erwinia chrysanthemi, approved in 2011 as part of a combination regimen for acute lymphoblastic leukemia) to as much as three separate Phase 3 trials (rituximab’s 2006 approval for use with CHOP chemotherapy in newly diagnosed Non-Hodgkin Lymphoma patients).Despite the variance, certain thresholds are evident. For example, 75% of all applications and 56% of orphan indications were directly supported with at least one Phase 3 trial. Standards are predictably higher for non-orphan indications, where 88% of applications included a Phase 3 trial. Of indications approved without Phase 3 support, most were for patients who had failed or who demonstrated intolerance to earlier lines of therapy which is understandable given the limited treatment options available to these groups.In addition to demonstrating the range of required data, Figure 1 also reveals that 59% of all indications were approved with a single Phase 3 trial. Nearly three-quarters of all non-orphan drugs fall in this category and it is the most common scenario for orphan drugs as well. In the absence of specific guidance from regulatory agencies, this may serve as the best available proxy for establishing the scope of a clinical trial program necessary to gain approval.
Figure 1 - Number and Type of Pivotal Trials for Approved Cancer Drugs 2005-2011
insiteinvestigator™ is VOI’s proprietary database containing detailed information on design, endpoints, populations, size, placement, timelines, efficacy outcomes, and safety results for every pivotal trial supporting a cancer drug approved by the U.S. FDA from 2005 through 2011.
 Guidance for Industry: Clinical Trial Endpoints for the Approval of Cancer Drugs and Biologics. Food and Drug Administration. May 2007