SUBCUTANEOUS INJECTIONS OF 2-CHLORODEOXYADENOSINE FOR SYMPTOMATIC HAIRY-CELL LEUKEMIA

Purpose: To evaluate the clinical efficacy and safety of 2-chlorodeoxy adenosine (CdA) when administered by subcutaneous injection to patient s with symptomatic hairy cell leukemia (HCL), and to evaluate predicti ve factors for response.Patients and Methods: Seventy-three patients w ere given CdA as a subcutaneous injection once daily for 7 days. Compl ete remission (CR) required normalised blood counts and the absence of B-ly 7-positive bone marrow cells by flow cytometry. CdA concentratio ns in plasma following the first injection were analyzed by high-press ure liquid chromatography. Results: Fifty-nine patients (81%) achieved a durable CR after one (n = 55) or two courses, and 10 had a partial remission (PR). With a median follow-up duration of 20 months, no pati ent had a clinical relapse. Neutropenic fever that required intravenou s antibiotics occurred in 28 patients (38%). No toxicity at injection sites was observed. Incomplete response was predicted by an elevated l ymphocyte count and serum beta(2)-microglobulin level, and by a high p ercentage of hairy cells in the bone marrow. Plasma CdA levels were si milar to those achieved from intravenous administration. Conclusion: S ubcutaneous injection of CdA is safe and as effective as continuous in fusion without problems associated with the mode of administration. Ou r schedule simplifies CdA treatment and can be generally recommended. J Clin Oncol 13:989-995. (C) 1995 by American Society of Clinical Onco logy.