After just four patients Pfizer ends LTβR study

Only nine months ago Pfizer presented to investors its LTβR agonistic tetravalent antibody PF-07329640 at an R&D day, but already the project seems to be headed for the scrapheap. A phase 1 study began in May but was terminated in August having enrolled just four of a planned 220 patients, according to an update on the clinicaltrials.gov registry, which this week saw the trial marked as "terminated – strategic business decision". This doesn't necessarily mean that Pfizer has discontinued PF-07329640, but scrapping a trial that enrolled just four patients doesn't bode well; there are no other studies of PF-07329640 ongoing. The thinking behind this MAb was that it could activate LTβR (lymphotoxin-β receptor) to induce tertiary lymphoid structure formation and maturation. The development will be of interest especially to Roche, which in RO7567132 has the industry's only other clinical-stage LTβR agonist, according to OncologyPipeline. The precise format of this molecule is undisclosed. Meanwhile, the private UK biotech Mestag Therapeutics lists as its pipeline lead MST-0300, a MAb that conditionally agonises LTβR on co-engagement with FAP; MST-0300 had a preclinical poster at this year's AACR, and an IND filing is planned for 2025.

Industry projects with activity at LTβR

Source: OncologyPipeline.