- MHLW approved the combination of mosunetuzumab (Lunsumio) subcutaneous and polatuzumab vedotin (Polivy) IV for relapsed or refractory large B‑cell lymphoma.
- Phase III SUNMO (NCT05171647) reported ORR 69.7% vs 44.1% with R‑GemOx and median PFS 11.5 vs 3.8 months, a 59% reduction in progression/death risk.
- Adverse events occurred in 97.0% of combo patients versus 95.3% with R‑GemOx; key events included injection‑site reactions 52.6%, neutropenia 45.9%, anemia 30.4% and cytokine‑release syndrome 25.9%.
- Dosing: Lunsumio subcutaneous—cycle 1 Day1 5 mg, Days 8 and 15 45 mg; from cycle 2 onward 45 mg Day1 for up to 8 cycles; Polivy IV 1.8 mg/kg every 3 weeks for six doses (initial 90‑min infusion, may shorten to 30 min).
Approval
Chugai obtained MHLW approval for the combination of mosunetuzumab (Lunsumio) subcutaneous and polatuzumab vedotin (Polivy) IV for relapsed or refractory large B‑cell lymphoma in patients not eligible for autologous hematopoietic stem cell transplantation; this is the first worldwide approval for the combination.
SUNMO Phase III results
The multinational randomized SUNMO (NCT05171647) compared Lunsumio+Polivy with R‑GemOx; interim ORR was 69.7% (95% CI 60.7–77.8) versus 44.1% (95% CI 31.2–57.6), with a between‑group difference of 25.7% (97.5% CI 7.4–43.9); median PFS was 11.5 months (95% CI 5.6–18) versus 3.8 months (95% CI 2.9–4.1), representing a 59% reduction in risk of progression or death.
Safety
Adverse events were reported in 97.0% (131/135) of patients on the combination and 95.3% (61/64) on R‑GemOx; key events in the combination arm included injection‑site reactions (52.6%), neutropenia (45.9%), anemia (30.4%) and cytokine release syndrome (25.9%).
Indications and dosing
Approved indications cover diffuse large B‑cell lymphoma, high‑grade B‑cell lymphoma and relapsed/refractory follicular lymphoma (Grade 3B requires experienced pathological diagnosis). Lunsumio SC: cycle 1 Day 1 5 mg, Days 8 and 15 45 mg, then 45 mg Day 1 from cycle 2 for up to 8 cycles. Polivy IV: 1.8 mg/kg every 3 weeks for six doses; initial infusion 90 minutes, may shorten to 30 minutes if tolerated, with dose adjustments as appropriate.
