Pfizer has decided it will no longer try to bring its cholesterol-lowering antibody bococizumab to market, blaming the decision in part on payer resistance in the US.
The company's chief executive Ian Read said that experience with already-marketed drugs in the PCSK9 inhibitor class suggests that restrictions are being placed on prescribing "which has meaningfully dampened our initial expectations for the market potential".
The two marketed drugs in the class - Amgen's Repatha (evolocumab) and Sanofi/Regeneron's Praluent (alirocumab) - have yet to make significant headway in the market despite predictions they could become blockbusters. One reason seems to be kickback against their high prices compared to widely-used statin drugs.
Payer resistance is not the only reason for the decision, however, as Read also pointed to evidence that bococizumab's ability to reduce LDL cholesterol seemed to tail off over time, something that has not been reported with Repatha and Praluent.
There was also a higher-level of immunogenicity and injection site reactions compared to its rivals, which could suggest that the drug is stimulating neutralising antibodies that result in a reduction in efficacy.
With two expensive phase III trials already in hand, Pfizer is clearly reluctant to invest any more on obtaining the cardiovascular outcomes data that will be necessary to persuade payers to back the drug. This is not the first time it has had to take such a difficult decision - a few years ago it pulled another cholesterol-lowerer - CETP inhibitor torcetrapib - after re-evaluating its commercial potential.
Bernstein analyst Tim Anderson said the decision was unexpected given that the programme was in such a late-stage and is a blow to Pfizer's "already thin" pipeline, taking away a candidate that had been expected to approach $1bn in sales.
It is expected to lend further momentum to Pfizer's push for more acquisitions to bolster its R&D portfolio, just a few weeks after the company completed its $14bn takeover of cancer specialist Medivation.
"Our appetite for continued acquisitions or investments in business development remains firm," said Read.
News of the decision added to the discomfort at Pfizer, which also missed its earnings targets thanks to a poorer-than-expected sales performance by breast cancer blockbuster Ibrance (palbociclib) in the US.
The company still expects Ibrance to top $1bn in sales this year, however, and analysts have predicted it will eventually become a multibillion-dollar brand.