ASCO 2024 – acasunlimab impresses on overall survival

Genmab and BioNTech’s anti-PD-L1 x 4-1BB bispecific acasunlimab looked like one of the early losers of this year’s ASCO meeting, but full data reported yesterday, from a phase 2 post-checkpoint inhibitor NSCLC trial, might have given the project a chance. Overall response rates were still nothing to write home about, but a median overall survival of 17.5 months in one of the acasunlimab plus Keytruda arms was described by Truist analysts as “hands down the best efficacy data we have seen in second-line PD-1 progressed NSCLC”. On the downside, liver events still looked troublesome, and high patient dropout rates could raise eyebrows, though Truist noted that any grade 3 adverse event triggered discontinuation. The partners are planning to start a phase 3 trial by year-end; acasunlimab is the most advanced western PD-(L)1 x 4-1BB project, but Nanjing Leads Biolabs was recently cleared to begin a pivotal Chinese study. While activating the 4-1BB co-stimulatory pathway hasn’t always gone well, Genmab and BioNTech also have an anti-CD40 x 4-1BB bispecific, GEN1042, and are expecting to make a decision on that project’s pivotal development this year.

Acasunlimab’s updated ASCO results

Note: cutoff date 22 Mar 2024 for ORR & 1 May 2024 for OS. Source: ASCO 2024 poster.