Pfizer’s bid to defend its growth hormone franchise against a new, more convenient competitor has hit a snag. The FDA has pushed back approval of Pfizer’s once-weekly prospect, giving rival Ascendis Pharma a longer window in which to convert physicians and patients from current daily options without competition.
Ascendis, after suffering its own regulatory delay, won FDA approval for its once-weekly treatment for pediatric growth hormone deficiency last month. The approval positions Ascendis to start getting the market to switch from existing daily options, such as Pfizer’s Genotropin. Pfizer had hoped to get the green light from the FDA to sell its own once-weekly option somatrogon next month.
The FDA now looks set to miss its original PDUFA date. Late Friday, Pfizer revealed the FDA has pushed back the decision date by three months to review additional data. Pfizer submitted the data, potentially in response to a request from the FDA.
Details are scarce at this stage. Analysts at Jefferies shared some insights after talking to leaders at Opko Health, which originated the once-weekly candidate and partnered it with Pfizer in 2014. The extension will reportedly give the FDA more time to review longer-term efficacy and safety data from open-label extensions to phase 2 and 3 clinical trials.
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The extension pushes back the PDUFA date to January. In theory, the FDA could approve somatrogon before the PDUFA date, as happened when it delayed its decision on Ascendis’ Skytrofa. However, the delay could also be an early indicator of a bigger problem.
“OPK & PFE remain confident, but it is not clear to us exactly what FDA is focused on in the longer-term data. And, even though likely unique to the somatrogon program, w/ recent range of regulatory late-stage unpredictability, we think the delay increases risk incrementally,” the Jefferies analysts wrote in a note to investors.