SORAYA Data Shed Light on Responses to Mirvetuximab Soravtansine Based on Prior Bevacizumab Exposure

Clinicians now have more nuanced information on how the antibody drug conjugate mirvetuximab soravtansine (Elahere, Immunogen) works in patients with folate receptor alpha-high (FRα-high) platinum-resistant ovarian cancer based on their prior exposure to bevacizumab (Avastin), thanks to updated data from the phase 3 SORAYA trial (NCT04296890) presented recently.¹

Final overall survival (OS) and additional efficacy data were presented last month at the Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancer in Tampa, Florida. This followed the November 14, 2022, FDA accelerated approval of mirvetuximab soravtansine for adult patients with FRα-high platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have received 1 to 3 prior systemic treatments regimens.²

Approval was based on initial SORAYA results, which reported the primary end point, overall response rate (ORR), was 31.7% % (95% CI, 22.9-41.6) and the key secondary end point, median duration of response, (DOR), was 6.9 months (95% CI; 5.6-9.7) in 104 patients.³

All patients in the study had received prior bevacizumab—some in the frontline setting, some in the platinum-sensitive setting, and some in the platinum-resistant setting. (Six patients had bevacizumab in more than 1 setting). Results for 105 patients published in the Journal of Clinical Oncology (JCO) in January, after a median follow-up of 13.4 months, showed that 51% of the patients in SORAYA had 3 prior lines of therapy and 48% and a prior poly-ADP-ribose polymerase (PARP) inhibitor.⁴

Robert L. Coleman, MD, FACOG, FACS, presented the subgroup analysis of the SORAYA trial. The updated data showed a confirmed ORR of 32.4% (95% CI, 23.6%-42.2%), including 5 complete responses.¹ In the subgroup analysis involving previous bevacizumab exposure, results were as follows:

• The 94 patients treated with mirvetuximab soravtansine after receiving bevacizumab for platinum-sensitive ovarian cancer achieved an ORR of 34.0% (95% CI, 24.6%-44.5%).
• The 17 patients given mirvetuximab soravtansine after receiving bevacizumab in the platinum-resistant setting had an ORR of 17.6% (95% CI, 3.8%-43.4%).
• Among the 66 patients given mirvetuximab soravtansine as their first treatment in the platinum-resistant setting, investigators reported an ORR of 34.8% (95% CI, 24%-44.5%); among the 39 who had other therapies as their first treatment in this setting, ORR was 28.2% (95% CI, 15.0%-44.9%).

The presentation noted that updated safety outcomes for mirvetuximab soravtansine were consistent with prior data from SORAYA. Data reported after a median follow-up of 13.4 months in JCO showed that the most common treatment-related adverse events, all grade and grade 3-4, were blurred vision (41% and 6%), keratopathy (29% and 9%), and nausea (29% and 0%). Treatment-related AEs led to discontinuations in 9% of patients.⁴

References

1. Coleman RL. Mirvetuximab soravtansine(MIRV) in patients with platinum-resistant ovarian cancer with high folate receptor alpha (FRα) expression: evaluation of sequence of therapy on anti-tumor activity in the SORAYA study. Presented at: 2023 Society of Gynecologic Oncology Annual Meeting on Women’s Cancer; March 25-28; Tampa, Florida.
2. Joszt L. FDA approves mivetuximab soravtansine-gynx for platinum resistant ovarian cancer. The American Journal of Managed Care® website. November 15, 2022. Accessed April 26, 2023. https://www.ajmc.com/view/fda-approves-mirvetuximab-soravtansine-gynx-for-platinum-resistant-ovarian-cancer
3. Matulonis U, 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 trial (LBA 4). Gynecol Oncol. 2022;166(suppl_1):S50. doi:https://doi.org/10.1016/S0090-8258(22)01297-5
4. 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.