FAZ053 Monotherapy Shines in Rare Sarcomas Despite Combination Setbacks

In this first-in-human, phase I trial, FAZ053—an anti-PD-L1 monoclonal antibody—was evaluated as monotherapy and in combination with spartalizumab in 154 patients with advanced solid tumors. While around half of the patients experienced treatment-related adverse events (with few grade ≥3 events), FAZ053 showed a dose-proportional pharmacokinetic profile and a terminal half-life of 20.6 days at 1200 mg Q3W, establishing this dose for expansion. Notably, in dose expansion cohorts, FAZ053 monotherapy yielded encouraging responses in rare, typically "immune cold" sarcomas, with a 50% objective response rate in advanced alveolar soft part sarcoma and 30% in chordoma. However, the expected synergistic effect with combined PD-1 and PD-L1 inhibition was not observed.

These findings suggest that FAZ053 monotherapy may offer an effective treatment option for challenging sarcoma subtypes by overcoming inherent resistance to immunotherapy, while combination strategies may require further refinement to realize additional benefit.