Single Agent Cladribine Therapy for Hairy Cell Leukaemia: A 10-Year Retrospective Analysis with Focus on Drug Access Challenges and Need for Policy Change in Pakistan

Abstract

Objective: Hairy cell leukemia is an indolent B cell lymphoma presenting with constitutional symptoms, splenomegaly and cytopenia. Cladribine remains the standard first line therapy, used with or without rituximab with a remission rate of 85%-90%. We aim to analyze the results of using single agent cladribine in hairy cell leukemia, keeping in mind drug availability issues in our resource limited setting.

Methodology: A retrospective, descriptive cross-sectional study was conducted at a tertiary care hospital in Lahore. Medical records from 2015 to 2024 of patients who received single agent cladribine were reviewed and data collected. The complete remission rate and overall survival was documented. Moreover, source of drug procurement, cost borne by the patient and difficulty in drug access was documented.

Results: A total of 11 patients were included in the study. Common presenting symptoms were infection (81%) and fatigue (72%). On clinical examination splenomegaly was present in all patients. All patients received cladribine at dose of 0.1mg/kg/day IV continuous infusion for 7 days. 82% of patients achieved complete remission. In patients who achieved complete remission, no relapse was reported till date. All patients bought drug through unofficial channels with no support from government health insurance programs.

Conclusion: Cladribine demonstrates excellent efficacy in this cohort with a remission rate of 90.9% comparable to international data. However, it is not registered with drug regulatory authority of Pakistan and not available through official drug sources. Its lack of availability in Pakistan causes inequity in access and treatment delay for patients of hairy cell leukemia.