FDA Approves New Treatment for Soft Tissue Sarcoma
Adding the newly approved therapeutic to standard treatment improved survival for patients with advanced disease.
Olaratumab is intended to be used in combination with the cytotoxic chemotherapeutic doxorubicin. This combination is approved for treating patients diagnosed with types of soft tissue sarcoma for which an anthracycline chemotherapeutic such as doxorubicin would be an appropriate initial treatment and whose cancer cannot be cured with either radiation or surgery.
According to Richard Pazdur, MD, director of the FDA’s Office of Hematology and Oncology Products and acting director of the FDA’s Oncology Center of Excellence, “This is the first new therapy approved by the FDA for the initial treatment of soft tissue sarcoma since doxorubicin’s approval more than 40 years ago.”
Soft tissue sarcomas arise in soft tissues of the body such as the muscles, tendons, fat, blood vessels, lymph vessels, nerves, and tissues around joints. They are a diverse and rare group of cancers: The World Health Organization lists more than 50 subtypes of soft tissue sarcoma and estimates that they account for about 1 percent of all new adult cancers.
Most patients with metastatic soft tissue sarcoma that cannot be removed by surgery are initially treated with doxorubicin, either alone or in combination with other therapeutics. However, new treatments are urgently needed, as a recent study found that just 10 percent of patients were alive five years after starting systemic treatment.
Olaratumab is a therapeutic antibody that targets the protein PDGFR-alpha. The rationale for testing it as a potential treatment for patients with soft tissue sarcoma came from numerous research studies, including one published in the American Association for Cancer Research journal Molecular Cancer Therapeutics, which showed that therapeutic targeting of PDGFR-alpha had antitumor activity in human sarcoma xenograft models.
The randomized phase II clinical trial that provided the basis for the FDA approval of olaratumab for soft tissue sarcoma showed that targeting PDGFR-alpha had the same effect in patients as it had had in preclinical models. Results from the trial, which included patients with more than 25 subtypes of metastatic soft tissue sarcoma, were published recently in The Lancet. They showed that adding olaratumab to doxorubicin improved median overall survival by almost a year. The median overall survival was 26.5 months for those who received olaratumab and doxorubicin compared with 14.7 months for those who received only doxorubicin.
Olaratumab is the third new therapeutic approved by the FDA for the treatment of soft tissue sarcomas in the past 12 months. In October 2015, trabectedin (Yondelis) was approved for treating patients with liposarcoma or leiomyosarcoma that has progressed despite treatment with a chemotherapy regimen that includes an anthracycline such as doxorubicin. Then, in January 2016, eribulin mesylate (Halaven) was approved for treating patients with liposarcoma that has progressed despite treatment with an anthracycline-containing chemotherapy regimen.
The FDA approval was rendered on October 19, 2016.