Preclinical studies of tifcemalimab (anti-BTLA antibody) in combination with toripalimab (anti-PD-1 antibody) demonstrated synergistic anti-tumor effects. We present the outcomes of tifcemalimab with or without toripalimab in lymphoma patients. This is a 2-part, phase I study (NCT04477772). In Part A (dose escalation based on 3 + 3 design), patients with relapsed or refractory lymphoma received tifcemalimab monotherapy 1, 3 or 10 mg/kg for dose escalation and 3 mg/kg or 200 mg for dose expansion. For Part B (indication expansion), only classical Hodgkin's lymphoma (cHL) patients were included to receive tifcemalimab 100 or 200 mg plus toripalimab 240 mg due to poor tumor response in other subtypes. The primary endpoints were safety, maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). 25 patients in Part A and 46 in Part B were enrolled. No dose-limiting toxicities were observed, and MTD was not reached. The RP2D for tifcemalimab was 200 mg. Adverse events were predominantly Grade 1/2. Grade 3/4 treatment-related adverse events occurred in 3 patients (12·0%) in Part A and 15 patients (32·6%) in Part B. No fatal adverse events were observed. Tifcemalimab with or without toripalimab demonstrated a favorable safety profile in lymphoma patients.