DR-01 is a non-fucosylated human IgG antibody targeting CD94, expressed on terminal effector CD8+T cells, γδT cells, and NK cells leading to depletion of CD94-expressing malignant cells by antibody-dependent cellular cytotoxicity. Patients with relapsed/refractory (R/R) cytotoxic T cell lymphomas (CTLs) have no effective treatment options. This Phase 1/2 open-label study (NCT05475925) is assessing DR-01 safety, pharmacokinetics (PK), pharmacodynamics, and initial efficacy in R/R CTL patients.
As of May 2025, 64 patients with CTL (37 males) received intravenous DR-01 (0.3–10 mg/kg) in one of three induction regimens followed by monthly dosing. Median age was 53 (18–82 years) with a median of 3 (1–14) prior lines of therapy. Infusion-related reactions were the predominant treatment-related adverse events, occurring in 22 (34%) patients, primarily during initial administration and managed effectively with standard mitigation measures. At the selected dose (1 mg/kg; n=28), ORR was 54% (8 CR, 7 PR), with responses across multiple histologic subtypes; longest duration of response was ongoing at 16 months.
Of 35 baseline CTL study and 48 sourced samples (Samsung Medical Center, Stanford) evaluated for CD94 expression, 82 (98.8%) were CD94-positive by immunohistochemistry, consistent with literature showing high CD94 expression across CTL histological subtypes. Patients across a wide range of baseline CD94 expression (H-score range, 15–295) responded.
DR-01 continues to demonstrate promising safety and efficacy, supporting development as a potential CTL treatment. Preliminary data suggest that patients with CTL may benefit from DR-01 regardless of baseline CD94 expression.
