Pfizer Halts Phase 2 Trial of CD47 Drug Maplirpacept Amid $2.3B Trillium Acquisition Setback

2025Year6Month30Day,Pfizer Announces Termination of a Key Clinical Trial for Its2021Year of AcquisitionTrillium TherapeuticsThe two obtainedCD47The Second Drug——maplirpacept(Formerly known asTTI-622). ThisIIThe original aim of the study was to exploremaplirpaceptIn combination with the chemotherapy drug lenalidomide, it is used to treat recurrent or refractory diffuse large B-cell lymphoma.BPatients with lymphoma.

Pfizer spokesperson revealed that the reason for the trial termination was“Difficult to Recruit”, rather than issues related to the safety or efficacy of the drug. However, it is worth noting that the trial was originallymaplirpaceptThe most advanced project currently under research. Pfizer is still“Various Hematologic Malignancies”(such as multiple myeloma) to test this drug.

 Different Fates of Two CD47 Drugs

In Pfizer's acquisitionTrilliumWhen,maplirpaceptAndontorpacept（TTI-621) are the two majorCD47Main Project. Previously, Pfizer had terminatedontorpaceptDevelopment. According to Pfizer inSECDescription in the file,ontorpaceptCorrectCD47The“Don't Eat Me”Signal present“Strong”Inhibitory effect, andmaplirpaceptThe effect is“Medium”。

From the current results, the intensity of effect may not be the only determining factor; the complexity of drug development and practical challenges in clinical trials, such as patient recruitment, could also influence the final direction of research and development.

 The Continuous Setbacks Behind the Acquisition

This trial termination is another blow to Pfizer's M&A team.2021Year, Pfizer23Billion-dollar acquisitionTrillium Therapeutics, and those affected this timemaplirpaceptIt is one of the core assets of the transaction.

This is not Pfizer's only recent acquisition.“Waterloo”。2022Year, Pfizer54Billion-dollar acquisitionGlobal Blood TherapeuticsHowever, last year Pfizer withdrew a sickle cell disease drug that had been approved.Continuous setbacks have led the industry to reflect more on the effectiveness of Pfizer's mergers and acquisitions.

 The Dilemma of the CD47 Target

This incident once again highlightedCD47The Dilemma in Target Development —— This target, once regarded as the hope for new cancer drugs, is now encountering numerous obstacles. In2025At the beginning of the year,maplirpaceptStill only two of them remain at 2Phase and above research stagesCD47One of the drugs, the other isALX OncologyTheevorpacept。However,evorpaceptFailed in the stomach cancer trial earlier this year,ALXThe share price in the past12Plummeted in a few months93%。

CD47Pathways play a role in healthy cells within the immune system “Don't Eat Me” The role of signals, which cancer cells hijack to protect themselves. Most earlyCD47The drug indiscriminately targets the protein on both healthy cells and tumor cells, leading to safety concerns.

 Industry Insights

CD47Target from“Highly sought after”To“Repeated setbacks”, sounding the alarm for the entire biopharmaceutical industry. Even seemingly promising targets may face numerous unforeseen challenges during the drug development process, including safety issues, difficulties in clinical trial design and execution, and more.

For large pharmaceutical companies' M&A strategies, this incident also reminds them that when evaluating acquisition targets, they should not only focus on the potential of the target and the early data of the drug but also comprehensively consider various practical obstacles that may be encountered in subsequent R&D to reduce investment risks.

In the future,maplirpaceptThe trial results in hematologic malignancies will become the focus of attention in the industry, and whether it can reverseCD47The downturn in target research and development remains to be seen.