Bristol is no Lag3-ard

The giveaway about Bristol Myers Squibb’s bullishness on its anti-Lag3 MAb relatlimab came in 2016, when it unveiled a clinical programme comprising nearly 2,000 patients. Such faith was rewarded today when a key phase 3 study, Relativity-047, read out positively. True, this was in front-line melanoma, a relatively well-served cancer and not the biggest of all oncology indications, and the win was on progression-free survival; overall survival data are as yet immature. But Bristol should be congratulated for running a clearly designed head-to-head trial, in which relatlimab plus Opdivo beat Opdivo alone. Assuming that the data translate into an OS benefit, and that no serious toxicities emerge, a best-case scenario would give Bristol a brand new immuno-oncology strategy in Lag3 inhibition, which the group might conceivably use to replace its active but toxic CTLA-4 blocker Yervoy. Other groups developing Lag3-targeting assets will also take note; one of these is Australia’s Immutep, whose founder and chief medical officer is Frédéric Triebel, who back in 1988 first cloned Lag3. Immutep stock traded up 30% this morning.