ZEAL-1L: Niraparib Fails to Boost Pembrolizumab Maintenance in Advanced NSCLC
核心洞察
The phase III ZEAL-1L trial found that adding niraparib to pembrolizumab maintenance did not improve progression-free survival in advanced NSCLC without a targetable driver alteration.
Median PFS was 5.55 months in both arms among patients responding to first-line chemoimmunotherapy, with a hazard ratio of 1.00 and one-sided P=0.502.
Descriptive overall survival and CNS progression results showed no benefit, while grade 3-5 treatment-related adverse events rose to 31% with niraparib versus 14% with pembrolizumab alone.
The phase III ZEAL-1L trial, published in the Journal of Thoracic Oncology, tested whether adding the PARP (搜索) inhibitor niraparib to pembrolizumab maintenance could prolong benefit after first-line platinum chemotherapy plus pembrolizumab in advanced or metastatic NSCLC without a known targetable driver alteration. The randomized, double-blind, placebo-controlled study enrolled 666 patients with stage IIIB or IIIC disease unsuitable for definitive chemoradiotherapy or stage IV disease, randomizing 331 to niraparib plus pembrolizumab and 335 to placebo plus pembrolizumab.
The primary endpoint was unequivocally negative. Among the 401 patients entering maintenance with a complete or partial response, median PFS was 5.55 months in both arms (HR 1.00; 95% CI, 0.79-1.27; one-sided P=0.502). In the full intention-to-treat population, median PFS was 4.40 versus 4.37 months (HR 0.99; 95% CI, 0.82-1.19). Because the study used hierarchical testing, overall survival and CNS progression were analyzed descriptively after the primary endpoint failed; median OS was 24.77 versus 32.49 months in the response population (HR 1.20) and 21.36 versus 25.26 months in the ITT population (HR 1.16). The subdistribution HR for time to CNS progression was 0.98, despite niraparib's ability to cross the blood-brain barrier.
Subgroup analyses showed no clear benefiting population, including by histology or PD-L1 (搜索) status, and an exploratory PFS signal in patients with baseline brain metastases (HR 0.71) had a confidence interval crossing 1. Toxicity favored pembrolizumab alone: any treatment-related adverse event occurred in 74% versus 66%, grade 3-5 treatment-related events in 31% versus 14%, and any-cause grade 3-5 events in 44% versus 35%, with anemia, thrombocytopenia and neutropenia the main additions. One case each of acute myeloid leukemia (搜索) and myelodysplastic syndrome (搜索) occurred in the niraparib arm. The investigators place the result alongside negative PARP (搜索)-immunotherapy studies including ORION and the KEYLYNK program, and are conducting tumor biomarker analyses to assess whether homologous recombination repair deficiency identifies a more sensitive subset.