Clinical Trial: Pembrolizumab and Gemcitabine Chemotherapy in Leiomyosarcoma and Undifferentiated Pleomorphic Sarcoma

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional

Official Title: A Phase I Study to Assess the Safety and Tolerability of Pembrolizumab in Combination With Fixed Rate Gemcitabine Chemotherapy in Patients With Leiomyosarcoma and Undifferentiate

Brief Summary:

Soft tissue sarcomas (STS) are a group of rare mesenchymal neoplasms affecting all ages. STS most commonly present as localised disease but despite surgery and adjuvant treatment more than half of patients will develop recurrent or metastatic disease. Leiomyosarcoma (LMS), a malignancy of smooth muscle, is one of the most common STS and undifferentiated pleomorphic sarcoma (UPS) is a common sarcoma sub-type with aggressive symptoms.

Recent studies have demonstrated reasonable sensitivity of LMS to gemcitabine monotherapy with an objective response rate of 8-19%. However the overall survival is still only about 12 months which illustrates the critical clinical need for improved therapies for advanced STS and sarcoma in general.

In this study the investigators propose to combine the immune synapse checkpoint inhibitor with the cytotoxic and immune modulating agent, gemcitabine. It is hoped that this dual immunomodulatory approach will enhance the effect of pembrolizumab on PD-L1 expressing LMS and UPS, leading to a safe treatment with patient outcomes. This is a two part, phase I, single centre dose escalation and dose expansion study in the total of 24 patients with newly diagnosed metastatic or inoperable LMS and UPS. There will be approximately 12 patients in the dose escalation cohort (part A) and the starting dose will be a fixed dose rate (FDR) gemcitabine of 800 mg/m2 on day 1 and 8 of 21 days cycles in combination of 200 mg of pembrolizumab given as an infusion on day 1 every 3 weeks. The MTD cohort (part B) will then be expanded to a total of 12 patients in order to further evaluate the safety and tolerability of that dose as well as to preliminarily assess response to therapy.

The study is sponsored by Royal Marsden NHS Foundation trust and the funding for the study

Detailed Summary:

This is a two part, phase I, single centre dose escalation and dose expansion study to establish the safety, tolerability and pharmacokinetics of pembrolizumab in combination with different dose levels of fixed dose rate gemcitabine in patients with newly diagnosed metastatic or inoperable leiomyosarcoma and undifferentiated pleomorphic sarcoma (UPS), for whom gemcitabine monotherapy is deemed appropriate, or in patients with previously treated leiomyosarcoma and undifferentiated pleomorphic sarcoma, not including gemcitabine, with disease progression documented in the 12 weeks prior to enrolment.

There will be a maximum of 18 patients in the dose-escalation cohort (part A) and the starting dose will be a fixed dose rate (FDR) gemcitabine of 800 mg/m2 on day 1 and 8 of 21 days cycles in combination of 200 mg of pembrolizumab given as an infusion on day 1 every 3 weeks. There will be a minimum of three and a maximum of six evaluable patients entered per dose cohort and each patient will continue to receive treatment cycles of gemcitabine in combination with pembrolizumab for as long as he/she is, in the opinion of the investigator, deriving clinical benefit and continues to meet re-treatment criteria. Treatment will continue until disease progression or is stopped because of toxicity. There will be an option to continue pembrolizumab alone in patients with SD or response who stop gemcitabine for toxicity before completing 6 cycles of combination therapy. During the dose-escalation phase, safety, tolerability, biological and clinical activity will be assessed and the maximum tolerated dose (MTD) will be established.

The MTD cohort (part B) will then be expanded to a total of 12 patients in order to further evaluate the safety and tolerability of that dose as well as to preliminarily assess response to therapy.

primary outcome