Intermittent infusion of cladribine (CdA) in Previously treated patients with low-grade non-hodgkin's lymphoma

Thirty-six patients with previously treated low-grade non-Hodgkin's lymphoma (LG-NHL) were included in a phase II study between August 1990 and February 1994 and treated with 0.12 mg/kg CdA as a 2 h.i.v. infusion daily x V, q 28 days up to 6 courses. Twenty-three were refractory to previous chemotherapy while 13 were relapsed. Four patients had mantle cell lymphoma, 17 follicle centre cell derived lymphoma, 7 lymphoplasmacytoid lymphomas and, 8 had small lymphocytic lymphoma. The response rate was 42%, with 5 (14%) CR and 10 (28%) PR while 6 (16%) patients progressed during treatment. The median number of delivered CdA courses was 3 (1-6) in non-responding cases and 6 (2-6) in responders. The median time to progression was 9 mo for all patients, 23 mo for CR and 16 mo for PR patients. Toxicity was sometimes severe with 3 infectious deaths (1 pneumocystis carinii pneumonia, 1 gram negative septicemia, and 1 fungal pneumonia), and 6 grade 3 or 4 infectious episodes. We conclude that responses to CdA in this group of heavily pre-treated patients is impressive. However, toxicity is considerable and the rate of opportunistic infections is worrisome.