The objective of this subgroup analysis was to report phase 1/2 efficacy and safety data for sonrotoclax monotherapy in patients in China with relapsed or refractory mantle cell lymphoma (MCL) enrolled in the global BGB–11417–201 study.
BGB–11417–201 is an ongoing, global, open–label, phase 1/2 study. Eligible adults had prior exposure to ≥1 anti–CD20–based therapy and ≥1 Bruton tyrosine kinase (BTK) inhibitor. Patients received once–daily oral sonrotoclax in part 1 dose escalation and safety expansion at 160 mg or 320 mg, and in the part 2 efficacy expansion at 320 mg, using a gradual ≈4–week ramp–up. This subgroup analysis evaluated safety in parts 1 and 2 and efficacy in part 2. Efficacy endpoints included overall response rate assessed by independent review committee or investigator, time to response, duration of response, progression–free survival, and overall survival.
As of July 18, 2025, 55 patients in China were enrolled, with 45 treated at the 320–mg dose across parts 1 and 2. Median age was 66 years, and 73% were male. At baseline, 89% had stage III/IV disease, 27% had bulky disease, 64% had an intermediate or high simplified MCL International Prognostic Index, and 24% had TP53 mutation. Patients had received a median of 2 prior lines of therapy (range, 1-8); 47% had received ≥3 prior therapies, 20% had received ≥2 prior BTK inhibitors, and 80% discontinued their last therapy due to disease progression. Median study follow-up was 14.1 months (range, 0.1-28.7).
In part 2 (n=34), the overall response rate by independent review committee was 62%. Median time to response was 1.8 months, median duration of response was 15.8 months, and median progression–free survival was 11.9 months; median overall survival was not reached. Efficacy assessments by independent review committee and investigator were reported as similar.
Among patients in China treated with sonrotoclax 320 mg across parts 1 and 2 (n=45), neutrophil count decreased was the most common any–grade treatment–emergent adverse event (TEAE; 53%) and the most common grade ≥3 event (20%). Serious TEAEs occurred in 27%, most commonly pneumonia and platelet count decreased (each 7%). At data cutoff, 27% of patients remained on treatment and 58% discontinued treatment due to disease progression. TEAEs led to treatment discontinuation in 9% of patients and death in 2 patients (multi-organ disorder and respiratory failure; both assessed as related to disease under study and study treatment). Tumor lysis syndrome occurred in 7% (2 laboratory and 1 clinical), with all cases transient and resolving without sequelae, and none led to treatment discontinuation. The incidences of grade ≥3 and serious TEAEs and TEAEs leading to death or treatment discontinuation/modification were generally similar in patients in China versus the global population.
