Pfizer is ringing the changes as it exits the second quarter, tossing out a midstage pneumococcal vaccine candidate and a handful of phase 1 assets including a respiratory syncytial virus (RSV) prospect it picked up in last year’s ReViral takeover.
The quarterly pipeline update (PDF) features the removal of two phase 2 assets, including the previously disclosed defenestration of its oral obesity and diabetes candidate lotiglipron over safety concerns. The other phase 2 candidate to get the ax in the update is PF-06842433, a vaccine that was in development for the prevention of invasive and noninvasive pneumococcal infections in infants and children.
Pfizer ran (PDF) a phase 1/2 clinical trial of the seven-valent pneumococcal conjugate vaccine from 2018 to 2020. The vaccine candidate was designed to complement the pneumococcal coverage provided by Prevnar 13, but, with Prevnar 20 now approved, Pfizer has moved on from the program.
The update also covers the discontinuation of six phase 1 assets, including PF-07923567. The N-protein inhibitor, also known as RV-299, is one of the RSV candidates that Pfizer added to its pipeline in a deal to buy ReViral for $436 million upfront last year. Work on the most advanced program included in the deal, sisunatovir, continues, but Pfizer has decided it can do without PF-07923567.
Pfizer is also jettisoning a pair of atopic dermatitis programs and another pair of solid tumor assets. In atopic dermatitis, the Big Pharma followed up the discontinuation of one topical “soft” JAK inhibitor last year by axing a similar molecule that it was studying in the same phase 1 trial. Alongside that, it has cut PF-07242813, a CD1a inhibitor, after wrapping up a phase 1 trial in healthy volunteers and atopic dermatitis patients.
The solid tumor discontinuations fall on the AXL/MERTK inhibitor PF-07265807 and the IL15 activator PF-07209960. Pfizer acquired the AXL/MERTK inhibitor in the Array BioPharma buyout, but evidence the mechanism lowers the immune activation threshold and boosts anti-tumor immunity has failed to yield a clinical candidate the drugmaker thinks warrants further development.
Finally, Pfizer has thinned its sickle cell pipeline 10 months after its buyout of Global Blood Therapeutics positioned it as a force in the indication. The discontinuation affects PF-07209326, an anti-E-selectin inhibitor that was in development at Pfizer prior to the Global Blood takeover. The confirmation follows the news last week that Pfizer is walking away from a sickle cell disease licensing deal with Syros Pharmaceuticals that it inherited from its takeover of Global Blood.