Low-dose dasatinib is active and well tolerated among patients with chronic-phase chronic myeloid leukemia (CML-CP), and may have clinical utility in the first-line setting, according to a study published in Cancer.1

As the efficacy of anticancer medicine — and therefore survival — improves, one of the biggest goals in oncologic care is to maintain efficacy while minimizing adverse events (AE). Dasatinib, a highly potent second-generation tyrosine kinase inhibitor, is currently approved for CML-CP at 100 mg once daily but has been associated with high rates of AEs (eg, pleural effusion, myelosuppression). A reduction in dose may lead to even further improved outcomes.

For this single-arm study, researchers assigned 75 patients with newly diagnosed Philadelphia chromosome (Ph)-positive CML-CP to receive dasatinib 50 mg once daily. Treatment was interrupted for grade 3 to 4 non-hematologic AEs and grade 4 neutropenia/thrombocytopenia, and was resumed upon adequate resolution. Routine blood counts with differential and blood chemistry were performed every 1 or 2 weeks in the first month and then every 4 to 8 weeks thereafter.

After a median follow-up of 9 months, 60 patients were evaluable for a response at 3 months.

Of study participants, 93% and 72% of patients reached BCR-ABL1 transcript levels of 10% or less and 1% or less, respectively, at 3 months, and the complete cytogenic response rate was 86% at 6 months and 88% at 12 months.

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After 1 year, major molecular response, molecular response with a 4.0-log reduction, and molecular response with 4.5-log reduction was reached by 79%, 71%, and 46% of patients, respectively.

Dasatinib 50 mg had a good tolerability profile. Nine (12%) of patients had dose interruptions after 14 days or less during the first 3 months of treatment due to AEs, but resumed treatment upon resolution to grade 1 or lower; only 1 patient resumed treatment with dose-reduction.

Reduced-dose dasatinib was safe and effective in the frontline setting, achieving high rates of response and even cost savings. The authors concluded that “A confirmation of these findings is warranted. A randomized study comparing 50 mg of dasatinib with the standard dose could be considered.”

Reference

  1. Naqvi K, Jabbour E, Skinner J, et al. Early results of lower dose dasatinib (50 mg daily) as frontline therapy for newly diagnosed chronic-phase chronic myeloid leukemia [published online May 3, 2018]. Cancer. doi: 10.1002/cncr.31357