Pfizer drops diabetes and cancer drugs from clinical pipeline

Pfizer sign
Publicly available evidence of the advancement of PF-06342674 has dried up in recent years. (Tracy Staton)

Pfizer has culled Type 1 diabetes and cancer drugs from its early-phase pipeline (PDF). The actions affect anti-IL7R antibody PF-06342674 and third-generation, mutant-selective EGFR tyrosine kinase inhibitor PF-06747775.

PF-06342674 has languished in Pfizer’s early-phase pipeline for years but PF-06747775, also known as mavelertinib, looked to be moving forward until recently. Mavelertinib’s status changed earlier this month when Pfizer stopped enrolling patients in a phase 1/2 non-small cell lung cancer (NSCLC) trial, despite being almost 100 subjects short of its target. The trial is continuing but won’t add to the 65 participants recruited to date.

Pfizer advanced mavelertinib into clinical development to meet the need for drugs that inhibit the secondarily acquired resistance mutation EGFR T790M. If Pfizer had shown mavelertinib was such a drug, it could have positioned the asset as a more selective way to target EGFR and nullify resistance. 

In October, Pfizer revised the phase 1/2 trial to assess the use of mavelertinib in combination with its CDK4-CDK6 inhibitor Ibrance or PD-L1 checkpoint inhibitor Bavencio. Pfizer planned to administer the combinations to patients after testing mavelertinib as a single agent, both in previously treated and treatment-naïve patients. However, nine months after making the changes, Pfizer stopped enrolling patients in the trial. 

Pfizer is yet to explain the action. The FDA approved AstraZeneca’s Tagrisso in EGFR-mutated NSCLC earlier this year.
The demise of PF-06342674 was more gradual. Pfizer terminated a phase 1b trial of the antibody in multiple sclerosis in 2015 after enrolling four of an anticipated 60 participants. The Big Pharma said the termination was “a corporate decision” unrelated to the safety or efficacy seen in the trial. A phase 1b trial of the drug in Type 1 diabetes continued and went on to wrap up in September 2016. 

Since then, publicly available evidence of the advancement of PF-06342674 has dried up but the drug has remained listed in Pfizer’s phase 1 pipeline. That changed this week when Pfizer dropped the drug in one of its periodic pipeline culls.