D7404C00001 (SOUNDTRACK-B)

Adults >=18 with R/R B-NHL after >=2 prior systemic lines, ECOG 0–2, measurable FDG-avid disease, adequate marrow/liver/renal/cardiac function, required tumor sample, and module-specific histology/prior-treatment requirements.

Participants are eligible only if all core criteria and relevant module criteria are met. Core inclusion criteria: 1. Signed informed consent and compliance with protocol requirements. 2. Age >=18 years. 3. ECOG performance status 0-2. 4. Relapsed/refractory disease after at least 2 prior lines of systemic therapy (relapse after response, or SD/PD as best response to last line). 5. Histologically confirmed B-NHL by WHO classification (module-specific subtypes apply). 6. Fresh or FFPE tumor sample for histologic/molecular testing and MRD variant identification (region-specific exception noted in protocol). 7. If prior CD19-directed therapy received: locally confirmed CD19 expression after completion of CD19-directed therapy. 8. FDG-avid measurable disease: at least one bidimensionally measurable nodal lesion >1.5 cm or extranodal lesion >1.0 cm in longest dimension. 9. Prior nonhematologic toxicity resolved to Grade <=1 (except alopecia/fatigue; prior CRS/ICANS fully resolved; peripheral neuropathy <=Grade 2). 10. Adequate liver function: - total bilirubin <1.5 x ULN (or <3 x ULN with known Gilbert syndrome), - AST/ALT <=3 x ULN (or <5 x ULN with liver involvement by lymphoma). 11. Adequate hematologic function: - ANC >=1.0 x 10^9/L, - platelets >=75,000/uL, - hemoglobin >=9 g/dL, - absolute lymphocyte count <5 x 10^9/L, with protocol-defined transfusion/growth-factor stability windows. 12. Adequate renal function: CrCl >=45 mL/min (Cockcroft-Gault). 13. Adequate cardiac function: LVEF >=45% by ECHO or MUGA. 14. Reproductive criteria, including negative pregnancy test (WOCBP) and protocol-defined highly effective contraception windows for men and women. Module 1 (FL) additional inclusion: 15. Histologically confirmed classical follicular lymphoma (cFL; previously FL grades 1-3A). 16. R/R disease after >=2 prior systemic lines including >=1 anti-CD20 monoclonal antibody and >=1 alkylating agent or lenalidomide. Module 2 additional inclusion: 17. Histologically confirmed large B-cell lymphoma (WHO 2022), including transformed indolent B-cell lymphomas and FLBL (previously FL grade 3B).

CLL/Burkitt/Richter transformation, active CNS lymphoma, leukemic presentation, severe prior CRS/ICANS from CAR-T/TCE, active uncontrolled infection or uncontrolled viral hepatitis/HIV status per protocol, major recent cardiac disease, recent prohibited anti-cancer/transplant/T-cell engager therapies, pregnancy/breastfeeding.

Core exclusion criteria include: 1. Diagnosis of CLL, Burkitt lymphoma, or Richter transformation. 2. Active CNS involvement by B-NHL (limited protocol exception for remote, treated CNS history without recent recurrence). 3. Leukemic presentation of NHL (circulating malignant monoclonal lymphoid cells). 4. History of Grade >=3 CRS or ICANS after prior CAR-T or T-cell engagers. 5. Clinically relevant CNS condition/pathology that may interfere with safety evaluation (protocol examples include seizure disorders, stroke, severe brain injury, dementia, psychosis, etc.). 6. CNS involvement from active or prior autoimmune disease. 7. Concurrent or recent malignancy within 2 years (except protocol-defined negligible-risk/treated exceptions). 8. Medical/psychiatric conditions that increase risk or interfere with safe treatment/evaluation. 9. Active/uncontrolled infection requiring systemic therapy (including EBV) or recent unresolved COVID-19 per protocol conditions; known history of HLH/MAS. 10. HIV, active/chronic HBV or HCV, except protocol-defined controlled/eligible subgroups (including viral load/PCR requirements and monitoring/prophylaxis requirements). 11. Major cardiac abnormalities (eg, recent MI <=12 weeks, NYHA >=3 CHF, unstable arrhythmia/angina, QTcF >480 msec). 12. Residual nonhematologic AEs >=Grade 2 from prior therapy (except protocol-listed exceptions). 13. Prior T-cell engager therapy within 8 weeks before first planned surovatamig dose. 14. Prior CAR-T within 6 months, autologous HSCT within 12 weeks, or allogeneic HSCT/solid organ transplant within 24 weeks (plus immunosuppression/GVHD restrictions). 15. Chronic immunosuppressive therapy (except protocol-permitted limited steroid uses). 16. Any anticancer therapy or major surgery within 14 days (or 5 half-lives, whichever shorter) before first dose; live attenuated vaccine within 28 days. 17. Recent participation in another interventional study (within 28 days or 5 half-lives, whichever shorter). 18. Prior exposure to surovatamig or hypersensitivity to surovatamig/excipients. 19. Study staff/sponsor personnel involved in planning/conduct, prior enrollment in this study, unlikely compliance by investigator judgment. 20. Pregnancy or breastfeeding. Module 1 specific exclusions: 21. FLBL/FL grade 3B (for Module 1 cohort). 22. History of transformation to aggressive lymphoma (eg, LBCL, high-grade B-cell lymphoma).