Mirvetuximab Soravtansine Demonstrates Safety, Efficacy in Platinum-Resistant Ovarian Cancer With High Folate Receptor Alpha Expression

Mirvetuximab soravtansine demonstrated promising efficacy and safety for patients with platinum-resistant ovarian cancer with high folate receptor alpha (FRα) expression, according to results from the SORAYA trial published in the Journal of Clinical Oncology.

The current approved cytotoxic regimens available for platinum-resistant ovarian cancer “are associated with low response rates and considerable toxicities,” wrote lead author Ursula A. Matulonis, MD, Dana-Farber Cancer Institute, Boston, MA, and coauthors, adding, “Each successive line of therapy in [platinum-resistant ovarian cancer] is associated with progressively lower response rates, and unfortunately, fewer patients are healthy enough to tolerate further rounds of treatment.”

The single-arm phase 2 SORAYA study enrolled 105 evaluable patients with high FRα-expressing, platinum-resistant, advanced high-grade serious ovarian cancer between June 2020 and May 2021. All patients had received prior bevacizumab, 51% had 3 prior lines of therapy, and 48% had received a prior poly ADP-ribose polymerase (PARP) inhibitor. The primary end point of the study was confirmed objective response rate (ORR) with a secondary end point of duration of response (DOR).

With the median follow-up duration of 13.4 months, treatment with the ORR was 32.4% (95% confidence interval [CI], 23.6 to 42.2), including 5 complete and 29 partial responses. The median DOR was 6.9 months (95% CI, 5.6 to 9.7). Among patients with 1 to 2 prior lines of treatment, the ORR was 35.3% (95% CI, 22.4 to 49.9) vs 30.2% (95% CI, 18.3 to 44.3) in patients with 3 prior lines of treatment. In patients previously treated with a PARP inhibitor, the ORR was 38% (95% CI, 24.7 to 52.8) vs 27.5% (95% CI, 15.9 to 41.7) in those not previously treated with a PARP inhibitor.

The most common grade 3/4 treatment-related adverse events were blurred vision (6% grade 3) and keratopathy (8% grade 3, 1% grade 4). Treatment-related adverse events led to dose delay in 33% of patients, dose reduction in 20% of patients, and discontinued treatment in 9% of patients.

“Given the lack of effective therapies and poor prognosis for patients in this setting, the findings reported here underscore the potential for [mirvetuximab soravtansine] to become a biomarker-driven, standard-of-care option in this difficult-to-treat population,” concluded Dr Matulonis and colleagues.

Source:

Matulonis UA, Lorusso D, Oaknin A, et al. Efficacy and safety of mirvetuximab soravtansine in patients with platinum-resistant ovarian cancer with high folate receptor alpha expression: Results from the SORAYA study. J Clin Oncol. Published online January 30, 2023. doi:10.1200/JCO.22.01900