Efficacy of cyclin-dependent kinase 4/6 inhibitors in combination with hormonal therapy in patients with recurrent granulosa cell tumor of the ovary: A case series

Cyclin-dependent kinase inhibitors are approved in combination with hormonal therapy for treatment of hormone receptor expressing breast cancers. Activity in hormone receptor expressing gynecologic cancers has been postulated. Granulosa cell tumor of the ovary is one such cancer, which is relatively resistant to traditional cytotoxic chemotherapy. We report a case series of 7 heavily pre-treated patients with recurrent granulosa cell tumor of the ovary with a cyclin-dependent kinase inhibitor in combination with hormonal therapy, with 3 patients demonstrating partial response and 2 with stable disease. As of the data cutoff, 3 patients remained on treatment and 5 were alive, with true medians for duration of treatment and overall survival not reached (medians at data cutoff of 64 weeks and 62 months respectively). The treatment was generally well tolerated, with 1 patient choosing to discontinue treatment due to grade 3 fatigue. This regimen represents a possible option in the treatment of granulosa cell tumor of the ovary, warranting further prospective study for this unmet need in this indolent disease which often requires many lines of treatment.