Marstacimab prophylaxis in hemophilia A/B without inhibitors: results from the phase 3 BASIS trial.

Previous phase 1 and 2 trials established marstacimab safety and efficacy in adults with severe hemophilia A (HA) or B (HB).

先前的1期和2期试验确立了Marstacimab在患有严重血友病A（HA）或B（HB）的成人中的安全性和有效性。

BASIS is an open-label, marstacimab phase 3 trial in males aged 12 to 74 years with severe HA (factor VIII <1%) or moderately severe to severe HB (factor IX ≤2%).

BASIS 是一项开放标签、marstacimab 第 3 期试验，针对 12 至 74 岁男性重度血友病 A（因子 VIII <1%）或中度至重度血友病 B（因子 IX ≤2%）患者。

Participants without inhibitors received on-demand (OD) or routine prophylaxis (RP) therapy during a 6-month observational phase (OP) before receiving once-weekly subcutaneous 150 mg marstacimab during a 12-month active treatment phase (ATP).

在 6 个月的观察阶段（OP）中，没有抑制物的参与者接受了按需（OD）或常规预防（RP）治疗，然后在为期 12 个月的主动治疗阶段（ATP）中每周一次皮下注射 150 mg marstacimab。

Primary end points were annualized bleeding rate (ABR) for treated bleeds vs previous OD or RP during the OP, and safety.

主要终点是治疗性出血的年化出血率（ABR）与之前的开放标签（OD）或随机对照（RP）期间的比较，以及安全性。

Of 128 participants enrolled in the OP, 116 received marstacimab in the ATP.

在OP期间，共有128名参与者入组，其中116名在ATP中接受了marstacimab治疗。

In the OD group (n = 33), mean ABR decreased from 39.86 (95% confidence interval[CI], 33.05-48.07) in the OP to 3.20 (95% CI, 2.10-4.88) in the ATP, demonstrating superiority of marstacimab (estimated ABR ratio, 0.080 [95% CI, 0.057-0.113]; P < .0001).

在OD组（n = 33）中，平均ABR从OP的39.86（95%置信区间[CI]，33.05-48.07）降低到ATP的3.20（95% CI，2.10-4.88），显示了marstacimab的优越性（估计ABR比率，0.080 [95% CI, 0.057-0.113]；P < .0001）。

In the RP group (n = 83), mean ABR decreased from 7.90 (95% CI, 5.14-10.66) in the OP to 5.09 (95% CI, 3.40-6.78) in the ATP, demonstrating noninferiority and superiority of marstacimab (estimated ABR difference, -2.81 [95% CI, -5.42 to -0.20]; P = .0349).

在RP组（n = 83）中，平均ABR从OP的7.90（95% CI, 5.14-10.66）降低到ATP的5.09（95% CI, 3.40-6.78），显示了marstacimab的非劣效性和优越性（估计ABR差异，-2.81 [95% CI, -5.42至-0.20]；P = .0349）。

There were no deaths or thromboembolic events.

没有发生死亡或血栓栓塞事件。

Weekly subcutaneous marstacimab reduced ABR vs OD or RP therapy in the OP in individuals with severe HA or moderately severe to severe HB without inhibitors.

每周皮下注射marstacimab在严重HA或中度至重度HB患者中，与每日或间歇性治疗相比，降低了ABR，且这些患者没有抑制物。

Marstacimab was safe and well tolerated with no unanticipated side effects.

Marstacimab 安全且耐受性良好，未出现意外的副作用。

This trial was registered at www.clinicaltrials.gov as #NCT03938792.

本试验已在 www.clinicaltrials.gov 注册，注册号为 #NCT03938792。