New Treatment Shows Promise for Ovarian Cancer Patients
A groundbreaking study has revealed promising results for the use of niraparib (Zejula) as a first-line maintenance therapy for patients with ovarian cancer. The study, known as the PRIMA/ENGOT-OV26/GOG-3012 trial, expanded access to PARP inhibitors, such as niraparib, to patients with both BRCA-mutated and non-mutated tumors.
Led by Dr. Leslie M. Randall, MD, MAS, Professor and Director of Gynecologic Oncology at Virginia Commonwealth University, the study enrolled patients with newly diagnosed advanced ovarian cancer who were at high risk for recurrence after responding to first-line platinum-based chemotherapy. These patients either underwent neoadjuvant chemotherapy and achieved a complete or partial response, or had residual disease after frontline surgery. Participants were randomized in a 2:1 ratio to receive either niraparib or a placebo.
The primary endpoint of the study was progression-free survival (PFS), assessed through a blinded independent review. Secondary endpoints included overall survival (OS) and time to first and subsequent therapies. The study also stratified patients based on their response to platinum therapy and their tissue’s homologous recombination status.
The baseline demographics of the participants were similar to those of previous studies. The majority of patients had stage IIIC or IV disease, and around 67% had undergone neoadjuvant chemotherapy. Most patients received at least six cycles of chemotherapy. The study demonstrated a significant PFS benefit for patients receiving niraparib, particularly in the BRCA-mutated group. The HRd BRCA-wild-type group and HRp group also experienced benefits, although to a lesser extent.
Longer-term follow-up data further supported the use of niraparib in patients with ovarian cancer. The HRd group showed a highly significant PFS benefit, and the HRp group also demonstrated statistically significant results. While cross-trial comparisons are not statistically fair, the data for niraparib were comparable to those for bevacizumab (Avastin) alone in ovarian cancer treatment.
Regarding overall survival, the data for patients receiving niraparib are not as mature as those for other treatments. However, initial findings showed numerically favorable outcomes for niraparib compared to the placebo. Notably, patients in the HRp group exhibited a trend toward improved survival rates at 2 years. Additional research is required to draw conclusive results on the overall survival benefits of niraparib.
The safety profile of niraparib revealed some adverse events, with patients experiencing higher rates of thrombocytopenia, anemia, and neutropenia compared to the placebo group. However, it is worth noting that these toxicities are not solely attributed to PARP inhibitors but are also influenced by the advanced stage of ovarian cancer and previous treatments. Interestingly, niraparib also demonstrated off-target effects, including hypertension.
In conclusion, the PRIMA study provides compelling evidence for the use of niraparib as a first-line maintenance therapy for ovarian cancer patients. The trials demonstrated significant PFS benefits, particularly for the BRCA-mutated group, while still showing advantages for other biomarker subgroups. Although long-term OS data are still immature, the study suggests a potential trend toward improved survival rates with niraparib. Further investigation is necessary to fully understand the drug’s benefits and potential side effects.