Kelun-Biotech announced on July 15 that its antibody-drug candidate sacituzumab tirumotecan, or sac-TMT, developed in partnership with Merck, succeeded in a late-stage non-small cell lung cancer trial when combined with Merck’s Keytruda. The company said the Phase 3 trial met its primary endpoint by meaningfully improving progression-free survival alongside Keytruda and chemotherapy. A positive trend was also observed in overall survival compared to the combination of Keytruda and chemotherapy alone.
According to Kelun, sac-TMT addresses the PD-L1-negative non-squamous NSCLC population, which typically does not respond well to therapies like Keytruda. “The introduction of a TROP2 ADC to a PD-1 [monoclonal antibody] not only delivers ADC’s precise targeting and killing of tumor cells, but also activates the immune microenvironment through their synergetic mechanisms,” Kelun said in its release. “This strategy is expected to unlock the therapeutic potential of the PD-1 mAb in patients with PD-L1-negative or limited immune responses, breaking this therapeutic bottleneck.”
Analysts at Leerink Partners said this result provides the first direct proof-of-concept for an antibody-drug conjugate replacing platinum-based chemotherapy as part of first-line treatment for NSCLC. RBC analysts called it “another positive for Merck’s sac-TMT franchise, as it extends the validated sac-TMT + Keytruda combination from the PD-L1-positive population . . . into the more challenging PD-L1-negative segment,” where immuno-oncology agents plus chemotherapy remain standard care.
Merck partnered with Kelun through a $1.4 billion licensing agreement signed in December 2022 that covers seven antibody-drug conjugate candidates for cancer. Dean Li, president of Merck Research Laboratories, said at that time, “Advances in ADC technologies are yielding a new generation of candidates designed to more precisely target and deliver potent anticancer agents to the tumor site.”
The latest results follow a May victory when sac-TMT demonstrated significantly better overall survival and progression-free survival compared to physician’s choice intervention among certain patients with advanced or recurrent disease. RBC analysts are monitoring upcoming milestones including data expected at October's European Society for Medical Oncology meeting and further regulatory updates from global trials anticipated by 2028.
