Melissa Burgess, MD
Pembrolizumab (Keytruda) reduced the size of tumors in patients with a subtype of soft tissue sarcoma, according to updated interim results from the phase II SARC028, multicenter clinical trial, which were reported at the most recent meeting of the Connective Tissue Oncology Society (CTOS) in Lisbon, Portugal.
Although the response rate was approximately 20% in the overall cohort of patients with soft tissue and bone sarcomas, a response of 44% was shown in a subgroup of patients with undifferentiated pleomorphic sarcoma, who also experienced a reduction in tumor size.
"I think that the results from the correlative analysis of SARC028 will help to move the field forward, and they’ve laid out a nice foundation," said Melissa Burgess, MD.
Pembrolizumab has been approved to treat patients with melanoma, lung, and head and neck cancer, and continues to be explored in several other cancer types.
In an interview with OncLive
, Burgess, medical oncologist, assistant professor of Medicine, University of Pittsburgh Cancer Institute, discusses the significant findings from SARC028 and sheds light on the importance that clinical trials and immunotherapeutic agents will have in the future treatment of patients with sarcoma.
OncLive: Could you provide an overview of SARC028?
: SARC028 was a multi-institutional study, supported and sponsored by SARC, in which we had 12 different sites in the U.S. looking at single-agent pembrolizumab, an anti-PD1 inhibitor, in 2 cohorts of patients. We looked at soft tissue sarcomas, as well as bone sarcomas. In each of these cohorts, our goal was to look at 40 patients each, and, intentionally, in the soft tissue sarcoma arm, we specifically balanced our cohort among 4 different types of soft tissue sarcoma, including the 3 most common soft tissue sarcomas: undifferentiated pleomorphic sarcoma, leiomyosarcoma, as well as dedifferentiated, or high-grade, liposarcoma, and synovial sarcoma. In the bone sarcoma cohort, we looked at 3 different subtypes, including osteosarcoma, high-grade or dedifferentiated chondrasarcoma, as well as Ewing sarcoma.
Each of these patients received pembrolizumab as a single agent, at 200 mg through IV every 3 weeks. We examined them with the radiologic assessment first at 8 weeks, then every 12 weeks thereafter. These patients were also mandated to have biopsies done, so each patient had to have a biopsy done during screening, as well as at the 8-week mark. We also took samples of peripheral blood at multiple time points throughout the study.