A Randomized, Double-Blind, Placebo-Controlled, Multi-Center, Phase III Clinical Trial Evaluating the Efficacy and Safety of ZL-2306 (Niraparib) for Maintenance Treatment in Patients With Advanced Ovarian Cancer, Fallopian Tube Carcinoma or Primary Peritoneal Cancer (Collectively Referred to as Ovarian Cancer) Who Have Achieved Effective Response After First-line Platinum-containing Chemotherapy

Stage III, inoperable, or after debulking surgery (R1 or R2 score), stage IV, and patients after neoadjuvant therapy, with CR or PR after first-line therapy

384; 72% stage III/28% stage IV; 32% BRCA MUT

Maintenance

Double Blind, Randomized

PFS, OS, TFST, evaluated per RECIST

HRD by BGI assay (BGI Genomics, Shenzhen, China)

Nir maint (n=255) vs Placebo (n=129):

All patients (ITT):
PFS: 24.8 vs 8.3 months, HR: 0.45 (0.34-0.60, p<0.001)
OS: NR vs NR, HR: 0.63 (0.38-1.03, p=0.061)(16.9% data maturity)
TFST: 29.2 vs 11.9 months, HR: 0.45 (0.34-0.59, p<0.001) (57.0% data maturity)

HRD+ (incl. BRCA MUT):
NR vs 11.0 months, HR: 0.48 (0.34-0.68, p<0.001)

Exploratory analysis:
gBRCA MUT: NR vs 10.8 months, HR: 0.40 (0.23-0.68, p<0.001)
non-gBRCA MUT: 19.3 vs 8.3 months, HR: 0.48 (0.34-0.67, p<0.001)
HRD+ (excl gBRCA MUT): 24.8 vs 11.1 months, HR: 0.58 (0.36-0.93, p=0.022)
HRD-: 16.6 vs 5.5 months, HR: 0.41 (0.22-0.75, p<0.001)

Nir maint vs Placebo:
Serious AE: overall (14.9 vs 3.9%); 1 AML and 1 MDS in Nir maint arm (1 death from AML)
Grade 3-4 AE: overall (49 vs 7%), anemia (18 vs 1.6%), decreased neutrophil counts (17.3 vs 1.6%), decreased platelet counts (14.1 vs 0.8%)

Niraparib with individually starting dose (ISD regimen) significantly improves PFS compared with placebo and is associated with a better safety profile

Li N et al. Treatment With Niraparib Maintenance Therapy in Patients With Newly Diagnosed Advanced Ovarian Cancer: A Phase 3 Randomized Clinical Trial. JAMA Oncol (2023) 9(9):1230-1237
https://pubmed.ncbi.nlm.nih.gov/37440217/