When Repligen announced Pfizer had pulled out of an SMA drug-focused partnership last week the news was accompanied by a 10% drop in the US drugmaker’s share price.
The withdrawal brought to an end a collaboration that began in December, 2012 when Pfizer licensed RG3039, which is a small molecule derivative of 2,4-diaminoquinazoline that increases the expression of a gene called SMN that is damaged in SMA sufferers.
The deal required that Pfizer pay for the majority of RG3039’s clinical development, while Repligen agreed to transfer production technology to the US drugmaker.
Fiona Cincotta, analyst at online trading site Finspreads, told in-Pharmatechnologist.com Pfizer’s decision to pull out of the collaboration was a surprise.
“Although initial trials on Repligen’s product RG3039 came back positive, later tests in Phase I were not so convincing for which Pfizer openly expressed their concerns back in June last year. However, with Repligen picking up a $1m milestone payment from Pfizer as late as January this year it looked like the collaboration might still be on track.”
She also questioned the wisdom of Pfizer’s withdrawal amid growing Big Pharma interest in the SMA market.
“Given that SMA affects 1 in 6000-10000 children and that Pfizer´s competitors are increasingly searching for potential SMA treatments to take hold of this hugely valuable market share, the move by Pfizer may not be such a smart one.”
Cincotta added that: “Pfizer will need to act quickly to regain investor confidence and seem to be proactive in their ability to take control of this market share.”
At present there are not drugs for SMA, although several drugmakers are working on them. Roche, for example, will buy its way into the market when it buys France’s Trophos and its post-Phase II drug candidate, olesoxime, later this year.
Similarly, Biogen Idec paid Isis Pharmaceuticals $7m (€6.1m) in January after their co-developed SMA drug candidate – SMNRx – made progress in clinical trials.