Phase II Trial of Ubamatamab Alone or in Combination With Cemiplimab in MUC16-Expressing SMARCB1-Deficient Malignancies

Participants must not have any other malignancies within the past 2 years except for in situ carcinoma of any site, or adequately treated (without recurrence post-resection or post-radiotherapy) carcinoma of the cervix or basal or squamous cell carcinomas of the skin, ductal carcinoma in situ of the breast or low-risk early stage prostate adenocarcinoma with negligible risk of metastasis or death

Participants previously treated with T-cell-redirecting bispecific antibodies or MUC16-targeted therapies (including vaccines) are excluded. Participants who received CAR-T therapies within 30 days of first dose of study drug are also excluded. However, participants previously treated with immune checkpoint therapies such as anti-PD1, anti-PD-L1, anti-CTLA-4, or anti-LAG-3 immune checkpoint inhibitors are eligible, as long as they have been off these therapies for at least 60 days (~3 half-lives) prior to initiation of study treatment with ubamatamab.

Participants currently receiving anticancer therapies or who have received anticancer therapies (including chemotherapy and targeted therapies such as tazemetostat) within 2 weeks (14 days) prior to study Day 1 are excluded. Participants who have completed palliative radiation therapy more than 14 days prior to the first dose of the combination immunotherapy are eligible.

Participants with persistent grade ≥2 adverse events from prior systemic therapies that would confound timely detection of immune-related adverse events due to ubamatamab and/or cemiplimab or otherwise hinder patient participation in the clinical trial.