Genmab ends lung cancer drug development

Denmark's Genmab has decided not to continue the development of a drug for cancer, acasunlimab, which had reached phase 3 testing, after a review of its medicines pipeline.

The decision to end the programme comes 18 months after Genmab's former partner for the acasunlimab, BioNTech, pulled out of the alliance on the drug, a PD-L1x4-1BB bispecific antibody that was developed using Genmab's DuoBody technology platform and BioNTech’s expertise in immunomodulatory antibodies.

The drug is designed to bring about an antitumour response by activating T-cells and natural killer cells in PD-L1-expressing tumours, and was being tested in the phase 3 ABBIL1TY NSCLC-06 study as a monotherapy and in combination with MSD's PD-1 inhibitor Keytruda (pembrolizumab) in patients with non-small cell lung cancer (NSCLC) who had failed previous standard of care treatments with checkpoint inhibitors.

4-1BB, a T-cell co-stimulatory receptor also known as CD137, has long been a compelling target in cancer, with drugs targeting it triggering strong immune responses in lab and early-stage clinical testing. So far, no drugs targeting the receptor have reached the market, and several have been shelved after initial testing in human studies.

In a statement, Genmab said that the decision to shelve acasunlimab "reflects prioritisation of higher‑impact opportunities" across its late‑stage pipeline, as well as an "increasingly competitive landscape" in lung cancer.

The company's chief executive, Jan van de Winkel, said data for acasunlimab had been "encouraging", but that it has decided to focus its efforts on candidates with greater impact.

He highlighted AbbVie-partnered CD20xCD3 bispecific Epkinly (epcoritamab), Merus-partnered EGFRxLGR5 bispecific petosemtamab, and rinatabart sesutecan (Rina‑S), an FRα-directed antibody-drug conjugate that Genmab bolted on with its $1.8 billion acquisition of ProfoundBio in 2024, but which has been named in litigation between Genmab and AbbVie.

Already-marketed Epkinly is growing fast as a therapy for non-Hodgkin lymphoma (NHL) subtypes, with sales reaching $333 million in the third quarter of 2025, while petosemtamab made waves at the ASCO 2025 congress in head and neck cancer, and Rina-S has shown promise in ovarian cancer. All three are in various late-stage clinical studies.

"We remain committed to executing these programmes with speed and rigour," said van de Winkel. Genmab said the decision to abandon acasunlimab would not affect its 2025 financial guidance.