Pfizer: CD47 Blocker Discontinued, Trillium Acquisition Fails Pfizer abandoned all Trillium clinical candidates. This marks a complete $2.3 billion acquisition failure. CD47 blocker, T-cell engager, was discontinued. The drug class faces persistent development challenges. Pfizer has discontinued its remaining clinical-stage CD47 blocker and T-cell engager, acquired via the $2.3 billion Trillium Therapeutics acquisition. This action follows earlier pipeline cuts, signaling a total failure of the 2021 deal. The specific trial phase and endpoint triggering this event were not disclosed, but the decision reflects insufficient clinical promise. This discontinuation impacts Pfizer's oncology pipeline. Under FDA and EMA regulations, such decisions require formal notification to regulatory bodies and trial investigators. Pfizer will now proceed with trial termination protocols, including patient safety follow-up and data archiving. This aligns with 21 CFR Part 312.44, governing investigational new drug application withdrawal. No prior EMA action for this specific drug was found in BrunoSan's database. The failure underscores the high-risk nature of biotech M&A, particularly in challenging drug classes like CD47. Competitors like Gilead (magrolimab) and AbbVie (navitoclax) also face hurdles in this space. This event may shift investor focus towards more de-risked assets. Pfizer's strategic pipeline review will likely prioritize other oncology modalities moving into Q3 2026.