Lacutamab in Patients with Relapsed and Refractory Sèzary Syndrome: Results from the Tellomak Phase 2 Trial

• Published in: Blood 2023-11, Vol.142 (Supplement 1), p.185-185
• Main Authors: Bagot, Martine, Kim, Youn H., Geskin, Larisa J., Ortiz-Romero, Pablo L., Kim, Ellen, Mehta-Shah, Neha, Dereure, Olivier, Oro, Saskia, Beylot-Barry, Marie, Dalle, Stéphane, Jacobsen, Eric, Lansigan, Frederick, Ram-Wolff, Caroline, Khodadoust, Michael S, Battistella, Maxime, Gru, Alejandro A, Moins-Teisserenc, Hélène, Zinzani, Pier Luigi, Viotti, Julien, Paiva, Christine, Muller, Marianna, Porcu, Pierluigi
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2023-173806

Introduction Cutaneous T-cell lymphoma (CTCL) is a rare form of non-Hodgkin lymphoma. Sézary syndrome (SS) is a rare, aggressive and advanced type of CTCL. It has a unique biology, with high expression of KIR3DL2, a killer immunoglobulin-like receptor, reported in more than 85% of patients. SS is characterized by erythroderma, significant blood involvement with malignant SS cells, and lymphadenopathy. These patients suffer from debilitating itching and recurrent skin infections, often affecting quality of life (QoL). SS is distinguished by its poor prognosis, as the median survival of patients is approximately 5 years. Lacutamab is a first-in-class monoclonal antibody designed to specifically deplete KIR3DL2-expressing cells via antibody-dependent cell-cytotoxicity and phagocytosis. Methods TELLOMAK is an international, open-label, Phase 2 trial with multiple cohorts (NCT03902184). We report here results from Cohort 1, designed to evaluate safety and efficacy of single agent lacutamab in patients with relapsed/refractory (R/R) SS after at least 2 prior systemic therapies including mogamulizumab. Patients had blood stage B2 (≥1000 circulating Sézary cells/mm 3) at screening based on central evaluation by flow cytometry. Patients with evidence of large cell transformation were excluded. Lacutamab 750 mg is administered as an intravenous infusion weekly × 5 weeks (w), every 2 w × 10, then every 4 w until progression or unacceptable toxicity. Primary endpoint was Objective Response Rate (ORR) by global response score based on the evaluation of 4 compartments: skin, blood, lymph nodes and viscera according to International Consensus criteria (Olsen 2011). Secondary endpoints included but not limited to additional efficacy endpoints, safety, QoL assessments. Results At the data cut-off of May 1, 2023, 56 SS patients were enrolled treated and evaluated in Cohort 1. Median age was 69 years (range: 42-86), the median prior lines of systemic therapies was 6.0 (range: 2-15), 60.7 % (n=34) had stage IVA1, 32.1 % (n=18) had stage IVA2 and 7.1% (n=4) had stage IVB disease at baseline, all patients (100%) had blood involvement (B2), 67.9% (n=38) had confluence of erythema covering ≥ 80% body surface area (T4), 35.7% (n=20) had lymph node lymphoma involvement (N3). Median follow-up was 14.4 months (95% CI 9.0-18.4). In the ITT population (n=56), Global confirmed ORR was 37.5% (n=21; 95% CI 26.0-50.6) including 2 CRs, with a median time to response of 2.8 months (range 1-9