Cell Therapeutics, Inc. has achieved the primary efficacy endpoint of its phase III EXTEND (PIX301) trial of pixantrone (BBR2778) for patients with advanced, relapsed aggressive non-Hodgkin's lymphoma (NHL) based on a preliminary intent to treat efficacy analysis.
Patients randomized to treatment with pixantrone achieved a high rate of confirmed and unconfirmed complete remissions compared to patients treated with standard chemotherapy (14/70 (20.0%) for pixantrone arm compared to 4/70 (5.7%) for the standard chemotherapy arm, p = 0.02). No patient (0%) in the standard chemotherapy arm achieved a confirmed complete remission compared to 8/70 (11%) of pixantrone recipients. Pixantrone treatment also significantly increased the overall response rate (CR/uCR+PR) with (26/70 (37.1%) for pixantrone arm compared to 10/70 (14.3%) for the control arm, p = 0.003). CR/uCR and ORR were determined by an independent assessment panel that was blinded to the treatment assignments.
The most common serious toxicities (>5%) seen in previous trials of pixantrone include grade 3 and 4 neutropenia and febrile neutropenia. Complete safety information is not yet available for the study, however, the study was monitored on an ongoing basis by an independent Data Safety Monitoring Committee and no serious concerns were raised. Seventy-four percent of patients discontinued therapy for disease progression or death, the majority of which were in the standard chemotherapy control arm.
CTI plans to submit complete study data for presentation at a major scientific conference. CTI also intends to request a pre-NDA meeting with the FDA and expects to begin submission of a rolling New Drug Application (NDA) to the FDA in early 2009.