In a comparison of generic and branded imatinib as first-line and second-line treatment of chronic myeloid leukemia (CML), researchers found that generic imatinib may produce inferior long-term outcomes.
The Novartis patent on imatinib expired in 2016, allowing for approval of generic products that offer a more affordable alternative to the branded drug. The multicenter retrospective cohort study, published in Clinical Lymphoma, Myeloma & Leukemia, evaluated efficacy outcomes in 41 patients with CML categorized into two groups: Group 1 (n=27) included newly diagnosed patients who received frontline generic imatinib, and group 2 (n=14) consisted of patients who began treatment with branded imatinib and were mandated to switch to generic imatinib as second-line treatment.
At a median follow-up of 36 months, overall survival in group 1 was 85 percent, with 81 percent of patients achieving a complete cytogenetic response. At 24 months, 48 percent of patients achieved a major molecular response. Notably, 14 patients (52%) switched to nilotinib because of treatment failure and side effects.
In group 2, 13 patients (93%) achieved cytogenetic and molecular response at 36 months follow-up. One patient receiving branded imatinib lost complete cytogenetic and major molecular response, then switched to generic imatinib after five months.
The authors concluded that “generic imatinib as second-line therapy does not have deleterious effects on patient outcomes, [but] first-line generic imatinib showed suboptimal efficacy compared with branded imatinib.” The study may be limited by the small sample size of the location.
Source: Islamagic E, Hasic A, Kurtovic S, et al. The efficacy of generic imatinib as first- and second-line therapy: three year follow-up of chronic myeloid leukemia patients. Clin Lymphoma Myeloma Leuk. 2017 February 16. [Epub ahead of print]