Exceptional response to trastuzumab deruxtecan in recurrent neuroendocrine cervical cancer: A case report

Neuroendocrine cervical carcinomas (NECC) are a rare and aggressive cervical cancer subtype that account for 1-1.5 % of all cervical cancers. Treatment options for recurrent NECC are limited and anticipated response rates are low. Trastuzumab deruxtecan (T-DXd), an antibody drug conjugate with a topoisomerase I inhibitor payload, recently received FDA approval for previously treated patients with HER2+ (IHC3 + ) metastatic solid tumors. Data regarding use of T-DXd in NECC is very limited and it is unclear whether this histology was represented in the trial leading to approval. We sought to describe this unique case of a patient with recurrent NECC who experienced a complete and durable response to T-DXd.

This is a case report and review of the literature. Written informed consent was obtained by the patient prior to submission.

We describe a 44-year-old patient with recurrent, metastatic NECC who progressed following two prior lines of therapy, the most recent of which included a multi-drug regimen with topotecan (a topoisomerase I inhibitor). IHC of her tumor tissue demonstrated 3 + HER 2 expression leading to the decision to proceed with treatment with T-DXd. She experienced a partial response (64 % decrease by RECIST) at C6 and subsequent complete response which has now been maintained for > 1 year. She has tolerated therapy well with manageable toxicities and has not required treatment interruption to date.

This report demonstrates the role of biomarker driven therapy for rare and aggressive cancer subtypes such as NECC and demonstrates efficacy of T-DXd after previous exposure to topoisomerase I inhibitors.