Phase 2 Trial of Abemaciclib in Dedifferentiated Liposarcoma Meets Primary End Point

Treatment with abemaciclib resulted in progression-free survival in 74% patients with advanced progressive dedifferentiated liposarcoma (DD LPS), researchers from Memorial Sloan Kettering Cancer Center in New York, New York, reported at the Connective Tissue Oncology Society (CTOS) 2018 Annual Meeting in Rome, Italy.¹ In addition, a subset of patients saw a prolonged clinical benefit, and had stable or responding disease 2 years or longer following initial receipt of the medication.

Abemaciclib is a CD4K inhibitor, meant to address the CDK4 amplification that occurs in more than 90% of patients with well-differentiated/dedifferentiated liposarcoma (WD/DD LPS). According to presenter Mark Dickson, MD, this sarcoma subtype is characterized by a CDK4 expression level that is 10-fold that seen in normal fat cells, and the expression is specific to the WD/DD LPS subtype.

To investigate the clinical benefit of abemaciclib in patients with WD/DD LPS, the investigators sought to enroll up to 30 patients in a single-center, phase 2 trial. The trial would be considered positive if at least 15 patients did not experience progression.

During the period of August 2016 to June 2018, the investigators were able to enroll 24 patients, although 1 patient became inevaluable for the primary end point because of consent withdrawal.

Of the 23 evaluable participants, 17 individuals with DD LPS were progression-free at 12 weeks (95% confidence interval [CI], 58%-94%) and median progression-free survival was 30 weeks. One patient had a partial response, with a response rate of 4%. By October 2018, the data cutoff date, 9 patients maintained stable disease.

The investigators noted an analysis of paired tumor biopsies is ongoing; this research seeks to uncover predictors of clinical benefit across this small sarcoma subset.

Read more of Cancer Therapy Advisor‘s coverage of the CTOS 2018 meeting by visiting the conference page.

Reference

1. Dickson MA, D’Angelo S, Gounder M, et al. Phase 2 study of the CDK4 inhibitor abemaciclib in dedifferentiated liposarcoma. Presented at: CTOS 2018 Annual Meeting; Rome, Italy: November 14-17. Paper 020.