Dasatinib Tops Imatinib for Ph+ Acute Lymphoblastic Leukemia

In continuation of my update on dasatinib and imatinib

Dasatinib is associated with improved survival for pediatric patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL), according to a study published online Jan. 16 in JAMA Oncology.

Shuhong Shen, M.D., Ph.D., from the Shanghai Jiao Tong University School of Medicine, and colleagues conducted an open-label randomized trial at 20 hospitals in China involving patients aged 0 to 18 years with Philadelphia chromosome-positive ALL. Patients were randomly assigned to either daily dasatinib or imatinib (92 and 97 patients, respectively) in the context of intensive chemotherapy without prophylactic cranial irradiation.

The researchers found that the four-year event-free and overall survival rates were 71.0 and 88.4 percent, respectively, in the dasatinib group and 48.9 and 69.2 percent, respectively, in the imatinib group. The four-year cumulative risk for any relapse was 19.8 and 34.4 percent in the dasatinib and imatinib groups, respectively; the four-year cumulative risk for an isolated central nervous system relapse was 2.7 and 8.4 percent, respectively. There was no difference between the treatment groups in the frequency of severe toxic effects.

"The present study provides promising early outcome data supporting the use of a dasatinib-based regimen for Philadelphia chromosome-positive ALL," write the authors of an accompanying editorial. "It also highlights some key challenges that remain in the management of this disease."

Several authors disclosed financial ties to pharmaceutical companies, including Bristol-Myers Squibb, which manufactures dasatinib.

https://en.wikipedia.org/wiki/Dasatinib

FDA Expands Approval of Sprycel (dasatinib) to Include Treatment of Children with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia in Chronic Phase

In continuation of my update on Sprycel(dasatinib)

Bristol-Myers Squibb Company (NYSE:BMY) announced the U.S. Food and Drug Administration (FDA) has expanded the indication for Sprycel(dasatinib) tablets to include the treatment of children with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) in chronic phase (CP). This approval for Sprycel in pediatric patients with Ph+ CML in chronic phase was granted under priority review, and the indication received orphan drug designation from the FDA. The safety and efficacy of Sprycel in pediatric patients was evaluated in two pediatric studies of 97 patients with CP-CML: an open-label, non-randomized, dose-ranging trial (NCT00306202) and an open-label, non-randomized, single-arm trial (NCT00777036). Among the 97 patients in the two studies, 51 patients (exclusively from the single-arm trial) had newly diagnosed CP-CML, and 46 patients (17 from the dose-ranging trial and 29 from the single-arm trial) were resistant or intolerant to previous treatment with imatinib.

Sprycel is associated with the following Warnings and Precautions: myelosuppression, bleeding-related events, fluid retention, cardiovascular events, pulmonary arterial hypertension, QT prolongation, severe dermatologic reactions, tumor lysis syndrome, embryo-fetal toxicity and effects on growth and development in pediatric patients.¹.

“While chronic myeloid leukemia is rare in children, accounting for less than three percent of all pediatric leukemias, it is often more aggressive in younger patients than in adults and until recently, there have been few available treatment options,”^2,3 said Vickie Buenger, President, Coalition Against Childhood Cancer. “The FDA’s decision to approve the expanded use of Sprycel in children with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase may bring new hope to these patients and their families.”

“Our decision to pursue an expanded indication for Sprycel is indicative of our commitment to exploring pediatric applications within our broad development program,” said Johanna Mercier, head, U.S. Commercial, Bristol-Myers Squibb. “We are pleased this option is now available for appropriate pediatric chronic phase CML patients and their physicians.”

As part of its commitment to children and adolescents with cancer, Bristol-Myers Squibb continues to explore pediatric applications for investigational oncology agents within its broad development program. In addition, Bristol-Myers Squibb supports organizations and initiatives focused on pediatric patients and their families.

Long-term dasatinib findings support first-line use in CML

In continuation of my update on dasatinib

Final DASISION study findings confirm dasatinib to be an effective, long-term treatment for patients with a new diagnosis of chronic phase-chronic myeloid leukaemia (CP-CML).

 dasatinib

After 5 years, 61% of 259 patients randomly assigned to receive dasatinib 100 mg/day were still taking the tyrosine kinase inhibitor (TKI), while 63% of the 260 patients started on imatinib 400 mg/day continued with their treatment, the investigators report in the Journal of Clinical Oncology.

The primary endpoint of complete cytogenetic response (CCyR) at 5 years had been achieved by 28% of dasatinib-treated patients and 26% of their imatinib-treated counterparts, although the researchers note that these values may have been higher if bone marrow samples had been tested in the patients at the end of the study.

Cumulative 5-year rates of major molecular response (MMR) and molecular responses with a 4.5-log (MR4.5) reduction in BCR-ABL1 transcripts from baseline were also comparable in the dasatinib and imatinib treatment arms, at 76% versus 64%, and 42% versus 33%, respectively, say Jorge Cortes, from the University of Texas MD Anderson Cancer Center in Houston, USA, and co-authors.

Five-year estimated overall survival was 91.0% for the dasatinib group and 90.0% for those given imatinib. And estimated progression-free survival was a corresponding 85.0% and 86.0% with 4.6% and 7.3% of patients transforming to accelerated or blast phase CML during a period of follow-up that continued beyond TKI discontinuation.

In all, 84% of dasatinib-treated patients and 64% of imatinib-treated patients achievedBCR-ABL1 of 10% or less within 3 months of treatment. Compared with patients who did not reach this target, these individuals were more likely to achieve CCyR, MMR and MR4.5over 5 years, had higher rates of overall and progression-free survival, and were less likely to have transformation.

Cortes et al note that no new adverse effects were reported for dasatinib or imatinib by the end of the 5-year study period and just 15% and 11% of adverse effects were grade 3 or 4 in the groups, respectively.

Patients given dasatinib had higher rates of grade 3 or 4 neutropenia (29 vs 24%), anaemia (13 vs 9%) and thrombocytopenia (22 vs 14%) but lower rates of other nonhaematological side effects, except for any grade of pleural effusion (28.0 vs 0.8%). Discontinuation for drug-related side effects occurred in 16% and 7% of dasatinib- and imatinib-treated patients, respectively.

Pulmonary hypertension was reported in 5.0% and 0.4% of the dasatinib and imatinib groups, respectively, with 12 of the 14 diagnoses deemed to be drug related. Arterial ischaemic events were "uncommon" in both groups, affecting 5.0% and 2.0%, respectively.

However, there was a "disproportionate number" of deaths from infection in the dasatinib versus imatinib groups (11 vs 1), with seven deaths reported between 69 days and 4.5 years after dasatinib discontinuation.

"It will be important to prospectively and intentionally look at a possible imbalance in the occurrence of infections and, if present, determine a possible mechanism(s) for dasatinib-related infectious complications", the investigators comment.

"These results suggest that first-line dasatinib should continue to be considered a standard first-line therapy for patients with newly diagnosed CML-CP", the researchers conclude.

While patients given dasatinib were more likely to achieve early treatment milestones, the authors explain that the high rates of CCyR and overall survival in both treatment arms mean a longer follow-up period and larger study population are likely needed to demonstrate any significant difference in survival between the TKIs.