Take the L.

Is there a difference between PD-1 and PD-L1 inhibitors? Well, obviously, but what about when it comes to treatment outcomes? That’s hard to say since they never really go up against one another on study.  This systematic review and meta-analysis asks just that. Across 19 prospective trials randomizing >11K patients to an inhibitor of PD-1 (e.g., pembro, nivo, cemiplimab) or PDL-1 (e.g., atezo, avelumab, durvalumab) versus something else, anti-PD-1 inhibitors conferred superior progression-free (HR 0.73) and even overall (HR 0.75) survival. This advantage with PD-1 inhibitors persisted across sensitivity analyses. Why the difference? One thought is that blocking PD-1 blocks all its interactions whereas blocking PD-L1 still allows for PD-1 to bind to PD-L2, which yes apparently is a thing. TBL: Anti-PD-1 may work better than anti-PD-L1 agents. | Duan, JAMA Oncol 2019