Abbvie leaves I-Mab out in the cold

A couple of weeks ago I-Mab’s stock fell 20% on no apparent news, and it was only yesterday that many investors discovered the possible reason: Abbvie is slowly walking away from the companies’ 2020 collaboration on I-Mab’s anti-CD47 MAb lemzoparlimab. Formally the companies “continue to collaborate on ... anti-CD47 MAb therapy”, with no change in milestones available, according to I-Mab’s SEC filing. But the writing for lemzoparlimab is on the wall: last month Abbvie terminated a multiple myeloma trial, and now it is scrapping the remaining western study, in AML and MDS. Though the multiple myeloma move was said to be down to strategic considerations, at Asco lemzoparlimab showed 70% and 50% rates of anaemia and thrombocytopenia respectively in an azacitidine combo in MDS; perhaps the focus is to avoid such toxicity with follow-on projects. Lemzoparlimab studies in China, where Abbvie never had rights, continue, and I-Mab says it plans to start a phase 3 MDS trial in the near term. With no involvement from the big pharma group lemzoparlimab now joins the growing list of CD47 disappointments.