Impact of prognostic factors on outcome in a phase III study comparing alemtuzumab to chlorambucil as first-line therapy for B-cell chronic lymphocytic leukemia (BCLL)

Abstract

7035 Background: CAM307 is a phase III, open-label, randomized controlled trial comparing alemtuzumab (CAM) with chlorambucil (CHLO) for previously untreated B-CLL. Methods: The trial enrolled 297 previously untreated patients requiring therapy according to NCI-WG criteria. Patients were randomized 1:1 to CAM (n=149) vs CHLO (n=148) using standard dosing regimens. Diagnosis, Rai stage, response and disease progression were confirmed by an independent response review panel. In the overall study population, CAM demonstrated significantly higher overall response rates (ORR) than CHLO (83 % vs 55%) and a significant improvement in PFS (p= 0.0001) with manageable toxicities1. Outcomes according to Rai stage and cytogenetics have been previously reported.1,2 A pre-specified subgroup analysis of response rates (RR) and progression-free survival (PFS) by prognostic factors was performed. Results: Additional analyses revealed statistically significant PFS advantage in favor for CAM vs. CHLO for patients with β-2 microglobulin =3 mg/L (p<0.0001) or marrow infiltration =90% (p=0.0001). Conclusions: CAM is significantly superior to CHLO relative to overall and complete RR and PFS in the overall study population of previously untreated patients with CLL, and in patients < 65 years of age, < 70 years of age, maximum lymph node size < 5cm, and, performance status <2. Campath deserves further study in patients with age = 70, patients with massive lymphadenopathy, and in those with poor performance status. 1. Hillmen, P et al, Blood 108(11), abstract 301 2. Robak, T et al, Blood 108(11), abstract 2092 No significant financial relationships to disclose. [Table: see text]