Serplurfluous?

Top Line: By now we all realize PD-1 axis inhibitors are a game changer for extensive-stage small cell lung cancer (ES-SCLC).

The Study: In the international double-blind phase 3 ASTRUM-005 trial, 585 patients with ES-SCLC receiving standard (at the time of trial design) first-line carbo/etoposide q3 weeks x 4 cycles were randomized 2:1 to +/- the addition of serplulimab. Serplu-what? That’s right, there’s now more PD-1 axis inhibitors on the market than ibuprofen brands. As hoped, median overall survival was significantly longer with the addition of serplulimab (15.4 months) than without (10.9 months), as was median progression-free survival (5.7 months versus 4.3 months). This benefit held across subgroups based on age, smoking status, and PD-1 expression—the latter again appearing to have little to no bearing on treatment response. Where does this leave us? Well, this will be the first PD-1 inhibitor to prove it is worth its weight for this indication, remembering the grandfather of PD-1 inhibition pembrolizumab failed where PD-L1 inhibition with atezolizumab and durvalumab prospered. These Henlius (read: the Chinese Big Pharma producer of serplulimab) -sponsored authors are quick to suggest the exceptional median survival here (15.4 months versus 12.3 with atezo and 12.9 with durva) is due to this fully humanized IgG4 monoclonal antibody binding to unique epitopes in PD-1. That or this is a completely different patient population from an opposite side of the world.

TBL: Serplulimab improves overall survival when added to first-line chemo for ES-SCLC, and its Chinese manufacturer would like to point out it achieved the longest median survival time on record. | Cheng, JAMA 2022