The Efficacy and Tolerability of Generic of Imatinib in a Very Specific Group of Chronic Myeloid Leukemia (CML)

Introduction:

Most of the patients with CML started to receive a generic formulation of imatinib (IM) in May 2013, available in the Public Health in Brazil.

The lack of information about the tolerability and efficacy of generics was a concern to patients and doctors who have been treating with Glivec, the original IM from Novartis since 2002.

Objectives:

To evaluate the efficacy and tolerability of generic of IM in CML chronic phase (CP) patients who had achieved a stable major molecular response (MMR) with Glivec before May 2013.

Methods:

The absolute level of BCR-ABL transcript from peripheral blood was serially measured every 3 to 6 months by RT-qPCR. Only level variation > 0,1% expressed on the International Scale and adverse events were noted.

Results:

Forty CML-CP patients in MMR defined as BCR-ABL (IS) £ 0,1% in at least to consecutive times, who started the generic IM in May 2013 were evaluated. All of them received 400 mg of generic IM during 24 months.

Of 40 patients, 24 (60%) had no variation on sequential analysis and 13 (32,5%) had one or two variation of BCR-ABL/BCR between 0,1% to 1,16%, but re-achieved MMR.

Two patients, due to compliance issue, lost MMR. One re-achieved MMR with generic imatinib, the other one with nilotinib.

One patient presented hepatic toxicity grade 3, and was switched to dasatinib, without lack of MMR.

Overall, MMR was maintained in all but one patient (98%).

Conclusion:

In this specific MMR group, the use of generic IM was found to be safe and highly effective in maintaining MMR.