The FDA has crushed MEI Pharma’s hopes of winning accelerated approval for its PI3K inhibitor on the strength of phase 2 data, delivering another blow to a class of cancer drugs that has been reshaped by a series of shifts in recent months.
Working with its partner Kyowa Kirin, MEI linked the PI3K inhibitor zandelisib to a 70% response rate in follicular lymphoma patients late last year in an open-label, single-arm phase 2 clinical trial At the time, MEI framed the data as supportive of its plans to talk to the FDA about the timing of a filing for accelerated approval. A lot has changed in the PI3K inhibitor space since MEI’s data drop.
In January, Gilead Sciences pulled an accelerated approval for Zydelig in follicular lymphoma after finding enrollment in a confirmatory study “an ongoing challenge.” Days later, Incyte pulled a submission for its rival PI3K inhibitor parsaclisib in the indication after talks with the FDA led it to conclude it would be impossible to complete confirmatory trials “within a time period that would support the investment.”
MEI forged ahead with its plans as rivals dropped out only for a meeting with the FDA to reveal that the agency now thinks a randomized clinical trial is “needed to adequately assess drug efficacy and safety of PI3K inhibitor drug candidates, including zandelisib.” The FDA is set to hold an advisory committee meeting next month to discuss the need for randomized data on PI3K inhibitors.
According to MEI, while the FDA has generally expressed a preference for randomized data, the recent meeting was the first time the agency told it data from a single-arm study would be inadequate to land accelerated approval. Investors reacted badly to the news, sending shares in the biotech down 40% to around $1 in premarket trading Friday morning. MEI CEO Daniel Gold set out the next steps.
“Clearly, the outcome of our recent FDA meeting is a disappointing development. Nonetheless we will continue to focus on the ongoing phase 3 COASTAL study as we consider options that provide the most expeditious approval pathway utilizing randomized data, and which we believe will demonstrate the potential of zandelisib to help patients. Today’s announcement in no way diminishes our conviction to the development of zandelisib and the promise of its emerging clinical profile,” Gold said in a statement.
MEI ended 2021 with $186 million in the bank. The money will see MEI through to the completion of enrollment in the phase 3 COASTAL study, according to Gold. Last month, MEI said its cash runway extends out to the end of the 2023 calendar year.