A Multicenter, Single-Arm, Open-Label, Phase II Trial of Mosunetuzumab in Combination With Tislelizumab for r/r FL

A Multicenter, Single-Arm, Open-Label, Phase II Trial of Mosunetuzumab in Combination With Tislelizumab for Relapsed/Refractory Follicular Lymphoma (r/r FL)

This is a multicenter, single-arm, open-label, investigator-initiated, phase II clinical trial designed to evaluate the feasibility, efficacy, and safety of Mosunetuzumab in combination with Tislelizumab in patients with relapsed/refractory follicular lymphoma (r/r FL).

The study aims to enroll approximately 22 adult patients who have received at least two prior systemic therapies, including anti-CD20 monoclonal antibody treatment. The primary endpoint is the complete response rate (CR), while secondary endpoints include objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety assessment. The trial will be conducted at multiple centers in China, with an estimated study duration from May 2025 to May 2027.

Inclusion Criteria:

1. Signed written informed consent.

2. Age ≥18 years.

3. Histologically confirmed relapsed/refractory follicular lymphoma (r/r FL).

4. Received at least two prior systemic therapies, including anti-CD20 monoclonal antibody therapy.

5. ECOG performance status 0-1.

6. Expected survival ≥12 weeks.

7. Measurable disease (longest diameter >1.5 cm).

8. Adequate organ function:

   • Hepatic function: Total bilirubin ≤1.5×ULN; AST/ALT ≤3×ULN.
   • Hematologic function: ANC ≥1.5 × 10⁹/L; Platelets ≥75,000/μL; Hemoglobin ≥10.0 g/dL.
   • Renal function: Serum creatinine ≤1.5×ULN or CrCl ≥50 mL/min (Cockcroft-Gault formula).

9. Women of childbearing potential must have a negative serum pregnancy test and agree to use contraception.

Exclusion Criteria:

1. Inability to comply with study hospitalization and restrictions.
2. Active infections (including tuberculosis) or immunocompromised status.
3. Prior history of severe hypersensitivity to similar agents.
4. CNS involvement of lymphoma.
5. Pregnant or breastfeeding women.
6. Uncontrolled comorbid conditions, including cardiovascular or autoimmune diseases.
7. Receipt of live attenuated vaccines within 4 weeks before enrollment.
8. Use of systemic immunosuppressants within 2 weeks prior to first dose.
9. History of drug or alcohol abuse in the past 12 months.
10. Any condition deemed inappropriate for study participation by the investigator.