The array of kinase-activating alterations in Philadelphia chromosome (Ph)-like acute lymphoblastic leukemia (ALL) has important therapeutic implications, according to an evaluation involving nearly 800 individuals.

Investigators assessed the frequency of Ph-like ALL via gene expression profiling of participants, all of whom had B-cell ALL. They looked at event-free and overall survival in Ph-like ALL (n=194) vs non-Ph-like ALL (n=604) patients. Among the results:

• 28% of young adults had Ph-like ALL; 20% of those 40 to 59 years of age and 24% of older adults had the Ph-like subtype.
• Overall, 23% of patients with Ph-like ALL experienced 5-year event-free survival, compared with 43% of those with non-Ph-like ALL.
• Kinase-activating alterations were seen in 88% of patients with Ph-like ALL.
• 11 new kinase rearrangements were identified, including 4 involving new kinase or cytokine receptor genes and 7 involving new partners for previously identified genes.