Interim safety summary of alemtuzumab vs. chlorambucil as front-line therapy for patients with progressive B-cell chronic lymphocytic leukemia (BCLL)

Abstract

6563 Background: CAM307, a Phase III, open-label, international, randomized trial compares efficacy and safety of alemtuzumab (CAMPATH, MABCAMPATH® [CAM]) to chlorambucil (CHLO) in B-CLL. Methods: Untreated Rai stage I-IV B-CLL patients are randomized 1:1 to CAM 30 mg IV 3 times a week for a maximum of 12 weeks or CHLO 40 mg/m2 PO once every 28 days, up to a maximum of 12 cycles. Patients with autoimmune thrombocytopenia, prior bone marrow transplant, active infection, positive CMV by quantitative PCR assay, secondary malignancy or CNS involvement are excluded. All CAM patients receive prophylactic antibiotic (trimethoprim/ sulfamethoxazole DS) and antiviral (famciclovir) during treatment and until CD4+ counts are ≥200 cells/μL. The primary endpoint is progression free survival; secondary endpoints include safety, overall survival and response rate. Results: Currently, 174 patients (123 males, 51 females; median age 59 years; 63% Rai I/II; 37% Rai III/IV) have been enrolled. Number and distribution of adverse events (AE) were similar: CAM 142; CHLO 130. CAM patients had more systemic infusion reactions, while CHLO patients had more gastrointestinal AEs. The mean grade for all adverse events was 1.5 for CAM and 1.6 for CHLO. Number and distribution of serious adverse events were similar: CAM 16, CHLO 15. CAM patients had infusion-related events involving fever and chills (none for CHLO) and CHLO patients had nausea/vomiting and thrombocytopenia (none for CAM). CMV infection reactivations occurred in 35 patients (CAM 32; CHLO 3). All 35 CMV reactivation cases resolved and 24 patients completed treatment per protocol. Only 7 of 32 CAM patients with CMV reactivation experienced symptomatic CMV infection, and they were successfully treated with IV ganciclovir or foscarnet. No treatment-related deaths have been reported. Conclusions: Preliminary reports show that therapy-naïve BCLL patients treated with CAM and CHLO have comparable safety profiles. Active screening allows for early diagnosis and effective CMV prophylaxis and CMV infection treatment. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration ILEX Products, Inc., an affiliate of ILEX Oncology ILEX Oncology, Inc. ILEX Oncology, Inc. ILEX Oncology ILEX Products, Inc., an affiliate of ILEX Oncology ILEX Products, Inc., an affiliate of ILEX Oncology