Open-label, Non-randomized, Multi-cohort, Phase 1b/2 Trial Investigating the Safety, Tolerability, and Antitumor Activity of STC-15 (a METTL3 Inhibitor) as a Part of Combination Therapy With Toripalimab in Participants With Selected Advanced Cancers
This early phase oncology trial will be conducted at various study centers to investigate the safety, tolerability, and antitumor activity of STC-15 (a METTL3 inhibitor) in combination with toripalimab (anti- programmed cell death 1 \[PD-1\]) in four different locally advanced unresectable or metastatic tumors such as indications: (1) in combination with toripalimab (anti- programmed cell death 1 \[PD-1\]) in locally advanced and unresectable or metastatic non-small cell lung cancer (NSCLC), (2) in combination with toripalimab in locally advanced unresectable or metastatic melanoma, (3) in combination with toripalimab in locally advanced unresectable or metastatic endometrial cancers, and (4) in combination with toripalimab in locally advanced or metastatic head and neck squamous cell carcinoma (HNSCC). This study comprises of 2 parts: a combination dose escalation part (Phase 1b) followed by an assessment of the combination treatment's antitumor activity (Phase 2). This study will be conducted in adult participants with advanced malignancies to characterize the safety, tolerability, PK, and clinical activity of STC-15 in combination with toripalimab.
• Estimated life expectancy ≥ 3 months.
• ECOG performance status 0 or 1.
• Measurable disease according to RECIST v1.1 as assessed by the local site investigator/radiology.
• Documented radiologic assessment of progression on the prior therapy before study entry.
• Have the ability to swallow, retain, and absorb oral medication.
• NSCLC (when applicable): Participants with AGAs (actionable genetic alterations) must have received targeted therapy unless contraindicated. Participants must not have received more than three previous lines of systemic treatment for unresectable locally advanced or metastatic disease. This must include at least a prior anti-PD-1/L1 alone or in combination with chemotherapy. Participants must have disease progression on prior anti-PD-1/L1.
• HNSCC (when applicable): Participants must have progressed on following prior lines: 2L or 3L recurrent/metastatic disease; regardless of PD-L1 score. Participants must not have received more than three previous lines of systemic treatment for unresectable locally advanced or metastatic disease. This must include at least a prior anti-PD-1/L1 alone or in combination with chemotherapy.
• Endometrial (when applicable): Participants must not have received more than three previous lines of systemic treatment for unresectable locally advanced or metastatic disease. This must include at least a prior anti-PD-1/L1 alone or in combination with chemotherapy. Participants must have disease progression on prior anti-PD-1/L1
• Melanoma (when applicable): Participants must not have received more than three previous lines of systemic treatment for unresectable locally advanced or metastatic disease. This must include at least a prior anti-PD-1/L1 alone or in combination with chemotherapy. Participants must have disease progression on prior anti-PD-1/L1.