Dr. Naqash and Dr. Chen on the Efficacy of Atezolizumab in Advanced Alveolar Soft Part Sarcoma

Abdul Rafeh Naqash, MD, an advanced fellow in the Early Clinical Trials Development Program and the Developmental Therapeutics Clinic at the National Cancer Institute, and Alice Chen, MD, head of the Early Clinical Trials Development Program and Developmental Therapeutics Clinic, at the National Cancer Institute, discuss the phase 2 trial evaluating the efficacy of atezolizumab (Tecentriq) in patients with advanced alveolar soft part sarcoma.

As of April 2021, 46 of 53 patients have been enrolled on a phase 2 trial (NCT03141684) studying the agent, 45 of whom have already received treatment, according to Naqash. Investigators reported an objective response rate of 37.2%, with a median duration of confirmed response of 16.6 months, and a median time to confirmed response of 3.5 months.

Interestingly, 3 patients who had been on a treatment holiday as per protocol had maintained their partial responses for a median duration of 8.6 months. These evaluations suggest that atezolizumab has promising clinical activity in patients with alveolar soft part sarcoma, Naqash says.

Future direction will focus on the addition of bevacizumab (Avastin) as an anti-angiogenesis agent in patients who have progressed on atezolizumab, according to Chen. Additionally, previous reports have indicated that a combination of pembrolizumab (Keytruda) and axitinib (Inlyta) have demonstrated promising activity in this patient population. Moreover, bevacizumab and atezolizumab have been examined in other histologies, such as hepatocellular carcinoma, with positive results, Chen says.

The combination is currently being examined in patients with alveolar soft part sarcoma in order to overcome resistance to atezolizumab, as the anti-angiogenesis component of bevacizumab could change the microenvironment and immunotherapy effect, Chen concludes.