Long term treatment of advanced endometrial cancer with lenvatinib and pembrolizumab

To describe a case of sustained disease control for over five years in a patient with recurrent, advanced endometrial cancer treated with lenvatinib and pembrolizumab, despite significant treatment-related toxicities.

We present a 49-year-old patient with grade 3, stage IVB endometrioid endometrial adenocarcinoma. After cytoreductive surgery, carboplatin and paclitaxel chemotherapy, and radiation therapy, the patient experienced progression with widespread metastases. She was then treated with lenvatinib (20 mg daily) and pembrolizumab (200 mg every three weeks). The patient experienced multiple treatment-related adverse events, including hypertension, colitis, hypothyroidism, adrenal insufficiency, and ocular toxicity, requiring dose adjustments and treatment interruptions.

Despite frequent toxicities, the patient achieved a durable response to lenvatinib and pembrolizumab. Five years after treatment initiation, imaging showed no metabolically active disease, with only minimal stable residual lesions. Careful management of adverse effects, including supportive care, dose modifications, and temporary treatment pauses, enabled continued therapy.

This case underscores the potential for long-term disease control with lenvatinib and pembrolizumab in advanced endometrial cancer, even in patients with proficient mismatch repair (pMMR) and low tumor mutational burden. Although toxicities can require treatment adjustments, they can often be effectively managed, allowing for prolonged therapy. Further research is needed to determine the optimal treatment duration and strategies to mitigate long-term side effects.