Pfizer undeterred in CD47 plans as competitors face pitfalls

Maybe it’s the result of pent up confidence accrued from dominating the COVID-19 landscape for almost two years, but Pfizer is certain that its CD47 portfolio won't get gobbled up by the kind of clinical woes that have befallen its rival Gilead. 

Pfizer executives were bullish during a second quarter earnings call Thursday that its two CD47 meds would not face the same setbacks seen from rivals Gilead and others. As a result, the New York pharma is staying the course. The update came from Chief Development Officer William Pao, M.D., Ph.D. during the earnings call. 

“Internally, we remain confident in our program with Trillium and we proceed with the programs that we are planning and we'll let the data speak for itself when they come in,” he said. 

The meds came from Pfizer's $2.3 billion buyout of Trillium Therapeutics last year, which brought two early-phase inhibitors of the CD47 macrophage checkpoint under the pharma's wing. The two candidates are designed to block CD47 while simultaneously delivering an “eat me” signal to macrophages. Pfizer snagged TTI-622, now called PF-07901801, and TTI-621, which focus mainly on hematological cancers. Only PF-07901801 made an appearance in Pfizer's pipeline update document (PDF) issued with earnings, noting that the therapy is in phase 2 development. 

Other companies have fared poorly in the CD47 field. Gilead had clinical holds placed on a number of its CD47 trials in January after an “apparent imbalance” in adverse effects in the study arms. Most of the holds were lifted in April, but not all. Gilead's magrolimab came from the $4.9 billion acquisition of Forty Seven in March 2020. 

AbbVie is also in the CD47 space thanks to a $2 billion upfront-biobucks R&D deal with Shanghai-based I-Mab, granting the U.S. company with access to the anti-CD47 monoclonal antibody lemzoparlimab. At the time of the September 2020 deal, AbbVie clearly had high hopes for the therapy, putting billions on the line. Fast forward to 2022, though, and one early-stage study in multiple myeloma has been terminated due to "strategic considerations," while another plugs away in myelodysplastic syndrome. 

The latest phase 2 data on lemzoparlimab will be presented at the European Society for Medical Oncology Congress 2022 in September, according to a July 18 press release from I-Mab.