Study of REGN6569 and Cemiplimab in Adult Patients With Advanced Solid Tumor Malignancies

• Status: Recruiting
• Trial end date: 2026-06-08
• Target enrollment: 0
• Participant gender: All

Summary

For dose escalation cohorts, the primary objective is to evaluate the safety and tolerability of REGN6569 as monotherapy lead-in and in combination with cemiplimab.

For dose expansion cohorts, the co-primary objectives are:

• To assess the preliminary efficacy of REGN6569 in combination with cemiplimab, as measured by objective response rate (ORR)

• To assess the preliminary pharmacodynamic activity of REGN6569 as lead-in monotherapy, as measured by intratumoral Glucocorticoid-Induced Tumor necrosis factor receptor-Related (GITR)+ Treg depletion

Secondary Objectives are:

For dose escalation cohorts:

• To assess preliminary efficacy of REGN6569 in combination with cemiplimab, as measured by ORR, disease control rate (DCR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS)

• To characterize the pharmacokinetics (PK) of REGN6569 alone and in combination with cemiplimab

• To assess the immunogenicity of REGN6569 and cemiplimab

For expansion cohorts:

• To characterize the safety profile in each expansion cohort

• To assess preliminary efficacy of REGN6569 in combination with cemiplimab, as measured by DCR, DOR, PFS, and OS

• To characterize the PK of REGN6569 alone and in combination with cemiplimab

• To assess the immunogenicity of REGN6569 and cemiplimab

• Phase: Phase 1
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Regeneron Pharmaceuticals
• Treatments: Cemiplimab

Criteria

Key Inclusion Criteria:

1. Dose escalation cohorts: Advanced stage (unresectable or metastatic) solid tumor malignancy, confirmed histologically or cytologically as defined in the protocol

2. Dose expansion cohorts: Advanced stage (unresectable or metastatic) head and neck squamous cell carcinoma, confirmed histologically or cytologically as defined in the protocol

3. Mandatory biopsies: Able and willing to provide tumor tissue at baseline and while on treatment, with at least 1 soft tissue lesion amenable to biopsy by ultrasound or computed tomography (CT)-guided biopsy

All Cohorts:

4. Has no prior history of immune checkpoint blockade (ICB) therapy

5. Has exhausted all approved available treatment options for their disease, with no standard therapy likely to convey clinical benefit as defined in the protocol

Key Exclusion Criteria:

1. Has previously received GITR-targeted therapy

2. Has received any previous systemic biologic therapy within 5 half-lives of first dose of study therapy as defined in the protocol

3. Has any condition that requires ongoing/continuous corticosteroid therapy (>10 mg prednisone/day or anti-inflammatory equivalent) within 14 days prior to the first dose of study therapy

4. Has ongoing or recent (within 5 years) evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments as defined in the protocol

5. Has a known history of, or any evidence of, interstitial lung disease, or active, non-infectious pneumonitis in the past 5 years. A history of radiation pneumonitis in the radiation field is permitted as long as pneumonitis resolved ≥6 months prior to first dose of study therapy

6. Has uncontrolled infection with human immunodeficiency virus, hepatitis B or hepatitis C infection, or diagnosis of immunodeficiency

7. Has received a live vaccine within 4 weeks of planned start of study medication. For dose escalation only: Has received a COVID-19 vaccination within 1 week of planned start of study medication or for which the planned COVID-19 vaccinations would not be completed 1 week prior to start of study.

8. Has had prior allogeneic stem cell transplantation or received organ transplants at any time, or autologous stem cell transplantation

Note: Other protocol-defined Inclusion/ Exclusion criteria apply