Response to Sotorasib in a patient with recurrent KRAS G12C-mutated low-grade serous ovarian cancer: a case report and literature review

Objectives: Low-grade serous ovarian carcinoma (LGSOC) is a rare subtype of ovarian cancer characterized by slow disease progression and relative resistance to conventional chemotherapy. Disease recurrence is common, and guideline-directed treatment options may become exhausted, underscoring the need for novel therapeutic approaches. This case report describes the clinical course and treatment response of a patient with recurrent, KRAS G12C-mutated LGSOC after 5 lines of previous therapy who was treated with the KRAS G12C small-molecule inhibitor sotorasib. Methods: In this case study, a patient with recurrent Stage IC3 LGSOC, whose tumor tested positive for a KRAS G12C mutation, received sotorasib 960 mg as an off-label therapy after disease progression on available guideline-directed therapies. Results: Treatment with sotorasib resulted in an ongoing, partial response on CT scans at 2 and 7 months after therapy initiation. CA-125 normalized rapidly and remains within normal limits to date. The patient has experienced no adverse events and has been able to maintain adherence to therapy. Conclusions: This case study documents a clinically successful treatment using sotorasib in LGSOC. This represents a novel targeted therapy approach for patients with KRAS G12-mutated recurrent LGSOC, suggesting benefit in this population that has not been documented to date.