First-line sacituzumab tirumotecan with tagitanlimab in advanced non-small-cell lung cancer: a phase 2 trial

Sacituzumab tirumotecan (sac-TMT, also known as MK-2870 or SKB264) is an antibody-drug conjugate targeting trophoblast cell surface antigen 2. We report the initial findings from the ongoing phase 2 OptiTROP-Lung01 study, evaluating the combination of sac-TMT and tagitanlimab (KL-A167), an anti-PD-L1 antibody, as first-line therapy in patients with advanced or metastatic non-small-cell lung cancer who lack actionable genomic alterations (cohorts 1A and 1B). Cohort 1A received sac-TMT (5 mg kg^-1, every 3 weeks) plus tagitanlimab (1,200 mg, every 3 weeks) in each 3-week cycle, whereas cohort 1B was treated with sac-TMT (5 mg kg^-1, every 2 weeks) plus tagitanlimab (900 mg, every 2 weeks) in each 4-week cycle, in a nonrandomized manner until disease progression or unacceptable toxicity. The primary endpoints included safety and objective response rate. This study was not powered for formal hypothesis testing. A total of 40 and 63 patients were enrolled in cohorts 1A and 1B, respectively. The median age was 63 years in both cohorts. An Eastern Cooperative Oncology Group performance status of 1 was observed in 97.5% and 85.7% of patients in cohorts 1A and 1B, respectively. In cohorts 1A and 1B, the most common grade ≥3 treatment-related adverse events were decreased neutrophil count (30.0% and 34.9%), decreased white blood cell count (5.0% and 19.0%) and anemia (5.0% and 19.0%). No treatment-related deaths were observed. After median follow-ups of 19.3 months for cohort 1A and 13.0 months for cohort 1B, the confirmed objective response rate in the full analysis set was 40.0% (16 of 40) and 66.7% (42 of 63), the disease control rate was 85.0% and 92.1% and median progression-free survival was 15.4 months (95% confidence interval 6.7-17.9) and not reached for cohorts 1A and 1B, respectively. sac-TMT plus tagitanlimab showed promising efficacy as a first-line treatment for advanced or metastatic non-small-cell lung cancer, with a manageable safety profile. ClinicalTrials.gov registration: NCT05351788 .