Pfizer hopes Gilead’s CD47 issues aren’t catching

2022 has so far been a year of clinical holds, and yet another has come courtesy of Gilead, which has halted some studies of its anti-CD47 project magrolimab after seeing adverse events. This is another blow to Gilead’s deal strategy – it paid $4.9bn for magrolimab’s developer Forty Seven in 2020 – but the news could also make Pfizer nervous. The pharma giant recently made its own CD47 move, buying Trillium for $2.3bn. Gilead did not give details of the adverse events, but the issue seems to be specific to a combination of magrolimab plus the chemo azacitidine. Evercore ISI’s Umer Raffat speculated that it could be related to cytopenia rather than anaemia; the latter has previously been seen with magrolimab. Notably, Pfizer’s TTI-621 and TI-622 are not being trialled alongside azacitidine, but other CD47 contenders are, including ALX Oncology’s evorpacept and I-Mab/Abbvie’s lemzoparlimab. Even the best-case scenario for Gilead, a delay rather than the end of magrolimab, could see it lose first-mover advantage in a very crowded field. The news also puts more pressure on the imminent readout from the Tropics-02 trial of Trodelvy, gained through Gilead's $21bn purchase of Immunomedics, another deal that could prove too rich.