A Phase 2 Study of Coltuximab Ravtansine (SAR3419) Monotherapy in Patients with Relapsed or Refractory Acute Lymphoblastic Leukemia (ALL)

• Published in: Clinical lymphoma, myeloma and leukemia myeloma and leukemia, 2016, Vol.16 (3), p.139-145
• Main Authors: Kantarjian, Hagop M., Lioure, Bruno, Atallah, Ehab, Leguay, Thibaut, Kelly, Kevin, Marolleau, Jean-Pierre, Escoffre-Barbe, Martine, Thomas, Xavier G., Kim, Stella K., Cortés, Jorge, Jabbour, Elias, O’brien, Susan, Bories, Pierre, Oprea, Corina, Hatteville, Laurence, Dombret, Hervé
• Format: Article
• Language: English
• Subjects: Cancer; Life Sciences; Medication; Pharmaceutical sciences
• ISSN: 2152-2650; 2152-2669
• DOI: 10.1016/j.clml.2015.12.004

Background Long-term disease-free survival in adult patients with acute lymphoblastic leukemia (ALL) remains unsatisfactory, and treatment options are limited for those patients who relapse or fail to respond following initial therapy. We conducted a dose-escalation/expansion phase 2, multicenter, single-arm study to determine the optimal dose of coltuximab ravtansine (SAR3419), an anti-CD19 antibody-drug conjugate, in this setting. Patients and Methods The dose-escalation part of the study determined the selected dose of coltuximab ravtansine for evaluation of efficacy and safety in the dose-expansion phase. Patients received coltuximab ravtansine induction therapy (up to 8 weekly doses); responding patients were eligible for maintenance therapy (biweekly administrations for up to 24 weeks). Three dose levels of coltuximab ravtansine were examined: 55, 70, and 90 mg/m2. The primary endpoint was objective response rate (ORR). Secondary endpoints included duration of response (DOR) and safety. Results A total of 36 patients were treated: 19 during dose escalation; 17 during dose expansion. One dose-limiting toxicity was observed at 90 mg/m2 (grade 3 peripheral motor neuropathy), and therefore 70 mg/m2 was selected for the dose-expansion phase. Five patients discontinued therapy due to adverse events (AEs). The most common AEs were pyrexia, diarrhea, and nausea. Of 17 evaluable patients treated at the selected dose, 4 responded (estimated ORR using Bayesian methodology: 25.47% [80% confidence interval: 14.18-39.6%]); DOR was 1.94 (range: 1-5.6) months. Based on these results, the study was prematurely discontinued. Conclusions Coltuximab ravtansine is well tolerated but is associated with a low clinical response rate in patients with relapsed/refractory ALL