When faster is not better: the 'surrogate' example
Since the election of President Trump in the US on January 20, 2017, there has been much speculation on how his presidency is going to affect the US healthcare sector.
Recently, Trump pledged to bring down drug prices in the US and to speed up the FDA approval process. Notably, among regulatory agencies, the FDA is already consistently faster than its European counterpart, the European Medicine Agency (EMA), as reported by the annual Centre for Innovation in Regulatory Science (CIRS) R&D briefing. In 2014, the CIRS R&D briefing stated that the median approval time for new active substances (NASs) was 343 days in the US compared to 418 days in Europe, despite the US approving more NASs that year (45 versus 30). According to the report, the efficiency of the FDA is due to its more frequent use of facilitated regulatory pathways (FRI), including Priority Review and Fast Track designations, which allow a faster market entry for qualifying drugs.
However, faster approval does not always guarantee a positive outcome. One way to speed up the drug development process is the use of surrogate endpoints in clinical trials. Surrogate endpoints are indirect measures of efficacy that are used to predict clinically important endpoints, and are most often used to obtain trial results sooner in order to treat serious or life-threatening diseases. An example of this seen in the oncology space is the use of progression free survival (PFS) as a surrogate for overall survival (OS), thus speeding up the regulatory approval process because of the shorter follow-up time required compared to longer survival studies. One instance of this method is shown by Roche’s Avastin (bevacizumab), which was initially approved in February 2008 under the accelerated approval program by the FDA for metastatic breast cancer patients in combination with paclitaxel on the basis of PFS as a surrogate endpoint.
However, this indication was withdrawn in November 2011 after the drug failed to demonstrate a survival benefit and its administration was associated with significant toxicity. A recent review of oncology drugs approved through FRI based on surrogate endpoints during 2008–2011 revealed that only five out of 15 NASs were able to show OS improvement in subsequent studies.
In an indication such as oncology, where the patient’s life is at stake, is it really worth putting more pressure on the FDA approval process? While the consensus is that it is important to provide fast access to new therapies for life-threatening conditions, the challenge for regulatory agencies over the coming years will be to implement a process that allows for the reduction of evidence required to launch a new drug without undermining their vital role in protecting public health.