Pegylated liposomal doxorubicin combined with trabectedin as a treatment option in uterine sarcomas: a single-institution retrospective analysis.

Objective: The use of conventional doxorubicin in combination with trabectedin leads to a considerable prolongation of progression-free survival in the treatment of uterine sarcomas but is associated with dose-limiting toxicities. Significant progression-free survival improvement was recently obtained through treatment prolongation with trabectedin single agent. We hypothesize that the therapeutic index of pegylated liposomal doxorubicin combined with trabectedin could be superior to the combination with conventional doxorubicin due to a more favorable toxicity profile.

Methods: In this retrospective cohort study, the clinical outcome was analyzed in patients with advanced or recurrent uterine sarcomas with measurable disease treated with pegylated liposomal doxorubicin 30 mg/m plus trabectedin 1.5 mg/m given every 3 weeks between January 2011 and April 2023 at the University Hospital in Innsbruck. Response evaluation was done every three cycles. Toxicity was evaluated according to the National Cancer Institute (NCI) Common Terminology Criteria on 107 administered cycles.

Results: A total of 21 patients were included in the study. In 67% (n=14) of patients, pegylated liposomal doxorubicin plus trabectedin was given as first-line treatment. One patient (5%) achieved a complete response and four (19%) a partial response, resulting in an objective response rate of 24%. Four other patients (19%) had stable disease. The median duration of the response was 14 months (range 3-74). Progression was recorded in 12 patients (57%). Median progression-free survival was 6 months (95% CI 1 to 11 months), while median overall survival was 26 months (95% CI 9 to 43 months). A median of 6 (range 1-11) cycles per patient were administered. Regarding grade ≥3 toxicity, neutropenia was recorded in 29%, thrombocytopenia in 14%, and febrile neutropenia in 19% of patients. Hematologic toxicity was the most frequent reason for dose delays (n=16) and dose reductions (n=5).

Conclusion: Our study found an overall clinical benefit for the combination of pegylated liposomal doxorubicin plus trabectedin in metastatic uterine sarcomas of 43% and appears to exhibit a favorable toxicity profile which allows prolonged administration of this regimen.