SKB264, a groundbreaking anti-TROP2 ADC, targets the poor prognosis marker overexpressed in 70% of NSCLC. Unleashing its potential with a sulfonyl pyrimidine-CL2A-carbonate linker, SKB264 strikes an optimal balance between circulation stability and tumor cell payload release, bolstered by an impressive drug-to-antibody ratio (DAR) of 7.4. According to the data presented at the ASCO 2023, as of February 9, 2023, around 43 patients were enrolled, and among them, 39 response-evaluable patients were there. The median follow-up was 11.5 months, with a median treatment duration of 5.7 months. Among the evaluable patients, the ORR was found to be 44%, followed by median DoR of 9.3 months.
For the EGFR wild type subgroup (previously received median 2 lines of therapy including anti-PD-1/L1), the ORR was 26% (5/19), DCR was 89% (17/19), median PFS was 5.3 months, and the 9-month OS rate was 80.4%. Apart from that, for the subgroup with TKI resistant EGFR mutant NSCLC, the ORR was 60% (12/20), DCR was 100% (20/20), median PFS was 11.1 months, and the 9-month PFS rate was 66.7%.
In terms of safety results, around 67.4% (29/43) of patients had grade ≥ 3 treatment-related adverse events (TRAEs). The most common grade ≥3 TRAEs were neutrophil count decreased (32.6%), anemia (30.2%), white blood cell count (WBC) decreased (23.3%,; stomatitis (9.3%), rash (7.0%), and lymphocyte count decreased (7.0%). Grade 4 TRAEs solely occur in neutropenia and white blood cell reduction. Lastly, there are no TRAEs that led to treatment discontinuation or death.
KOL insights
“Kelun's anti-Trop2 ADC SKB-264 / MK-2870, which Merck licensed along with other ADCs for $175m.” –Expert Opinion.
Conclusion
SKB264 at 5 mg/kg Q2W revealed promising antitumor activity and a well-tolerated safety profile in patients with relapsed or refractory locally advanced/metastatic NSCLC. Most importantly, the hematologic toxicities take the spotlight as the main TRAEs. Lastly, a Phase III study of SKB264 for the treatment of patients with locally advanced or metastatic EGFR mutant NSCLC who have failed EGFR-TKI therapy is ongoing in China, and global Phase III studies in NSCLC are planned
