Switch From Imatinib to Dasatinib May Benefit Certain Patients With CML-CP

Study findings support early monitoring of patients with chronic myeloid leukemia in chronic phase (CML-CP) treated with first-line imatinib, and suggest that switching to dasatinib in cases of suboptimal response may be clinically beneficial (Leukemia. 2020 Apr 7. Epub ahead of print).

“Early molecular response is associated with improved probability of deep molecular response and superior survival in patients with CML-CP. However, ~1 in 3 patients on first-line imatinib do not achieve this threshold,” explained Jorge E. Cortes, MD, Georgia Cancer Center, Augusta University, and colleagues.

Thus, Dr Cortes et al conducted the open-label, phase 2b DASCERN trial in which outcomes of early switch to dasatinib in adults with CML-CP and suboptimal response to first-line imatinib were evaluated.

Patients in the study were randomized in a 2:1 ratio to receive dasatinib 100 mg (n = 174) or continue imatinib at ≥400 mg (n = 86) for up to 60 months after randomization of the last patient, or until disease progression, treatment failure, unacceptable toxicity, withdrawal of consent, or study discontinuation occurred.

The main end point of the study was the 12-month rate of major molecular response (MMR), which was found to be 29% and 13% with dasatinib and imatinib, respectively (P = .005).

After ≥2 years of follow-up, 45 (52%) patients originally randomized to continue imatinib had crossed over to receive dasatinib. When treatment crossover was factored in, the 2-year cumulative MMR rate was 64% with dasatinib versus 41% with imatinib.

Both drugs yielded adverse events that were consistent with their respective, established safety profiles.

“The results of this first prospective study support early monitoring of patients treated with first-line imatinib, and suggest that switching to dasatinib in cases of suboptimal response may offer clinical benefit,” Dr Cortes and colleagues concluded.

“Further follow-up is needed to assess the long-term clinical benefit of early switching,” they added.—Hina Porcelli