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

Trial ID # NCT03709316; PRIME
Phase III
Drug Class DNA Damage Repair Pathway Inhibitors: PARP
Drug Name Niraparib
Alternate Drug Names MK4827, Zejula
Drugs in Trial Niraparib
Eligible Participant

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

Patients Enrolled

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

Therapy Setting


Study Design

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)

Clinically Significant Adverse Events

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

Contact Us
Contact Us

We are here to help! Send us a message below or give us a call at (858) 657-0282.