Maintenance treatment with niraparib plus best supportive care (BSC) does not improve outcomes, compared with BSC alone, in patients with advanced urothelial carcinoma (UC) that did not progress after first-line chemotherapy, a phase 2 trial suggests.
“Clinical selection based on platinum sensitivity did not succeed in selecting patients who may benefit from niraparib,” said Francesca Vignani, MD, of Ordine Mauriziano Hospital in Turin, Italy.
Dr Vignani presented these findings at the ASCO Genitourinary Cancers Symposium 2022.
The multicenter, phase 2 Meet-URO12 trial (ClinicalTrials.gov Identifier: NCT03945084) included 58 patients with unresectable, locally advanced, or metastatic UC. All patients had received 4 to 6 cycles of platinum-based chemotherapy as first-line treatment and had no evidence of disease progression.
The patients were randomly assigned 2 to 1 to receive niraparib plus BSC (n=39) or BSC alone (n=19). Sex distribution and median age were similar across the arms. Overall, the median age was 69.6 (range, 44.4-84.8) years, and 74.1% of patients were men.
Patients in the niraparib arm most commonly had visceral (48.7%) or bone (23.1%) disease, but patients in the BSC-alone arm most commonly had visceral (57.9%) or lymph node-only (31.6%) disease. Patients in the niraparib arm were more likely to have received cisplatin (61.5%) than patients in the BSC-alone arm (31.6%).
The median progression-free survival (PFS) was similar between the treatment arms — 2.1 months with niraparib and 2.4 months with BSC alone (adjusted hazard ratio, 0.87; 95% CI, 0.46-1.67; P =.68). This translated to a 6-month PFS rate of 28.2% for the niraparib arm and 26.3% for the BSC-alone arm.
There were 47 patients with known molecular profiles, and 21 harbored homologous recombination repair (HRR) mutations, including 6 with HRR mutations that were known to be pathogenic.
When the researchers evaluated only patients with HRR mutations, the median PFS was not different between the treatment arms; it was 2.0 months in both arms. Dr Vignani pointed out, however, that this analysis was limited by the small number of patients.
The incidence of grade 3 or higher treatment-emergent adverse events (TEAEs) was higher in the niraparib arm than in the BSC-alone arm — 65.8% and 15.8%, respectively.
The most common grade 3 or higher TEAEs in the niraparib arm were anemia, thrombocytopenia, and fatigue.
Although the trial did not meet its primary endpoint of improving PFS, Dr Vignani suggested that “future studies could evaluate potential synergy of PARP inhibitors in combination with other therapies, such as immune checkpoint inhibitors.”
Disclosures: This study was sponsored by the University of Turin in collaboration with Tesaro, Inc. Niraparib was supplied by GlaxoSmithKline. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Vignani F, Tambaro R, De Giorgi U, et al. Randomized phase II study of niraparib plus best supportive care (BSC) versus BSC alone as maintenance treatment in patients with advanced urothelial carcinoma (UC) whose disease did not progress after first-line platinum-based chemotherapy (PBCT): The Meet-URO12 trial. Presented at ASCO GU 2022; February 17-19, 2022. Abstract 442.
This article originally appeared on Cancer Therapy Advisor