Cladribine activity in adult langerhans-cell histiocytosis.

Langerhans-cell histiocytosis (LCH) results from the accumulation of tissue histiocytes derived from the same progenitor cells as monocytes. Because cladribine is potently toxic to monocytes, we conducted a phase II trial of cladribine. Cladribine was administered to 13 LCH patients at 0.14 mg/kg per day by 2-hour intravenous infusion for 5 consecutive days, every 4 weeks for a maximum of six courses. Median age was 42 years (range, 19 to 72) and median pretreatment disease duration was 99 months (range, 6 to 252). One patient was untreated, one had received prior prednisone only, one prior radiation only, six prior radiation and chemotherapy, and four prior surgery, radiation, and chemotherapy. Seven patients had cutaneous involvement, six multifocal osseous, six pulmonary, two each with soft tissue and nodal involvement, and four had diabetes insipidus. Of 13 patients, 12 were evaluable for response and all for toxicity. After a median of three courses (range, 1 to 6), seven (58%) patients achieved complete responses (two pathologic and five clinical) and two (17%) patients achieved partial responses; overall response rate, 75%. Median response follow-up duration was 33 months (range, 1 to 65). Seven patients experienced grade 3 to 4 neutropenia. Only one patient had a documented infection, dermatomal herpes zoster. At a median follow-up of 42 months (range, 5 to 76), 12 patients remain alive and one patient has died. Thus, cladribine has major activity in adult LCH and warrants further investigation in both pediatric and adult LCH as a single agent and in combination with other drugs.

Filgrastim for cladribine-induced neutropenic fever in patients with hairy cell leukemia.

Cladribine treatment of hairy cell leukemia (HCL) is complicated by neutropenic fever in 42% of patients despite documented infections being relatively uncommon. We performed a study of priming filgrastim followed by cladribine and then filgrastim again to determine if filgrastim would lead to a reduction of neutropenia and febrile episodes. Thirty-five patients received filgrastim and cladribine and were compared with 105 historic controls treated with cladribine alone. Cladribine was administered at 0.1 mg/kg/d by continuous infusion for 7 days. Filgrastim was administered at 5 micrograms/kg/d subcutaneously on days -3, -2, and -1 and then again after the completion of cladribine until the absolute neutrophil count (ANC) was >/=2 x 10(9)/L on 2 consecutive days (days +8, +9, etc). After filgrastim priming, the median ANC increased from 0.9 x 10(9)/L to 2.26 x 10(9)/L (2.5-fold increase), and after cladribine, the median nadir ANC in the filgrastim-treated group was 0.53 x 10(9)/L compared with 0.29 x 10(9)/L among historic controls (P =. 04). The median number of days to an ANC greater than 1.0 x 10(9)/L was 9 days in the filgrastim-treated group versus 22 days among historic controls (P < 10(-5)). The percentage of febrile patients, number of febrile days, and frequency of admissions for antibiotics were not statistically different in the two groups. Filgrastim regularly increases the ANC in patients with HCL and shortens the duration of severe neutropenia after cladribine. This phase II study, with comparison to historical controls, failed to detect any clinical advantage from the use of filgrastim and cladribine in the treatment of HCL. Accordingly, the routine adjunctive use of filgrastim with cladribine in the treatment of HCL cannot be recommended.

Bolus administration of cladribine in the treatment of Waldenström macroglobulinaemia.

This phase II clinical trial evaluated bolus cladribine as a single agent in Waldenstrom macroglobulinaemia (WM). Cladribine was administered to 20 patients at a dose of 0.12 mg/kg/d by 2 h intravenous infusion for 5 consecutive days at monthly intervals for three courses. Partially responding patients were continued on therapy until maximal response and/or prohibitive toxicity, to a maximum of eight courses. Complete responders were treated with one additional course of cladribine. After a median of three courses of cladribine, all 20 patients were evaluable; one achieved a complete response (CR) (5%) and 10 achieved a partial response (PR) (50%). The median duration of response follow-up was 28 months (range 1-37 months). Four of 7 (57%) untreated and 7/13 (54%) previously treated patients responded. The major toxicity encountered was myelosuppression with 60% of patients demonstrating grade 3 or 4 neutropenia. Non-haematological toxicities included two patients with herpes zoster and two patients with non-melanoma skin cancers. At a median follow-up duration of 20 months, 17 patients remain alive and three have died. We confirm that bolus cladribine is an effective and safe method of drug delivery in WM patients. Recommendations regarding the equivalence of the continuous infusion and bolus methods in untreated patients requires further study. Bolus cladribine is more convenient and less costly than infusional cladribine since it obviates the need for central catheters and infusional devices.

Long-term follow-up of patients with hairy cell leukemia after cladribine treatment.

Hairy cell leukemia is a chronic B-cell disorder that follows an indolent, but progressive course. Cladribine (2-chlorodeoxyadenosine) induces complete remissions in the majority of patients after a single course. We report the long-term outcomes, including response rates and their duration; time-to-treatment failure (TTF) rates; retreatment results; toxicities; and survival rates of patients treated at Scripps Clinic (La Jolla, CA). A total of 358 patients with hairy cell leukemia were treated with cladribine at 0.087 or 0.1 mg/kg body weight per day by continuous intravenous infusion for 7 days. The expected number of second neoplasms was based on the National Cancer Institute's Surveillance Epidemiology and End Results data. Of 349 evaluable patients, 319 (91%) achieved an initial complete response and 22 (7%) a partial response with an overall median duration of response follow-up of 52 months. Ninety patients (26%) had relapsed at a median of 29 months. The TTF rate for all 341 responders was 19% at 48 months, 16% for complete responders, and 54% for partial responders. Of 53 evaluable patients treated with second courses of cladribine at first relapse, 33 (62%) achieved complete responses and 14 (26%) partial responses. Twenty-seven patients (8%) developed second neoplasms (only 1 hematopoietic) with an observed-to-expected ratio of 1.88 (95% confidence interval, 1.24 to 2.74). The overall survival rate was 96% at 48 months. Single courses of cladribine induced long-lasting complete responses in the vast majority of patients. Relapse rates for complete responders were low. Patients who relapse can be successfully retreated with cladribine. Cladribine has high efficacy and a favorable acute and long-term toxicity profile when administered to patients with hairy cell leukemia.

Taking new skills home: regional training program builds HIV / AIDS capacity in Asia.

PIP: The AIDS Control and Prevention (AIDSCAP) Project's Regional AIDS Training and Education (RATE) Program over the course of 1993-96 trained 111 professionals from Thailand, Cambodia, Laos, Nepal, India, Bangladesh, the Philippines, Mongolia, Sri Lanka, Indonesia, and the South Pacific islands. Training was on behavior change communication, sexually transmitted disease management, policy development in HIV/AIDS prevention, and the training of trainers. To build the capacity of regional institutions to sustain such training after the end of AIDSCAP's involvement, centers of excellence were created at the following Thai universities: Dhurakijpundit University's Asia-Pacific Development Communication Center for training and behavior change communication, Mahidol University's Institute for Population and Social Research for policy development and journalism training, and the Women's Studies Center at Chiang Mai University for gender issues. The director of the RATE program from AIDSCAP's Asia regional office in Bangkok discusses the program's success and lessons learned on sustainability and capacity building.^ieng

Centers of excellence in Asia: a regional approach to capacity building.

PIP: Without effective AIDS prevention programs, 55 million Asians could be infected with HIV by 2020. Through the Regional AIDS Training and Education (RATE) Program sponsored by the Asia and Near East Bureau of the US Agency for International Development (USAID), the AIDS Control and Prevention (AIDSCAP) Project has conducted training courses in HIV/AIDS communication, the management of sexually transmitted diseases. HIV/AIDS policy, quality news reporting on HIV/AIDS, and training skills for more than 140 people from 10 countries since 1993. These activities aim to help individuals and organizations in Asia combat the spread of HIV/AIDS. To ensure that these capacity building efforts can continue after the RATE program ends, AIDSCAP is working with three Thai organizations to develop regional centers of excellence in key areas for HIV/AIDS prevention. The Institute for Population and Social Research of Mahidol University was chosen as the center of excellence in AIDS policy training, the Women's Studies Center of Chiang Mai University is the center of excellence for women and AIDS, and the Asia-Pacific Development Communication Center of Dhurakijpundit University is the center of excellence in communication and training skill development.^ieng