Dasatinib falls short of its response target in a small lymphoma trial
Four of 17 evaluable patients responded to dasatinib in a Japanese phase 2 trial of previously treated T follicular helper cell lymphoma. The single study missed its prespecified response threshold. Responses clustered in a small genetic subgroup, but the uncontrolled design leaves that finding exploratory and provides no validated rule for choosing patients.
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The primary endpoint fell short
Dasatinib produced four responses among 17 evaluable patients with previously treated T follicular helper cell lymphoma, a response rate of 23.5 per cent. That missed the prespecified 30 per cent threshold in this single peer-reviewed phase 2 study. Three responses were complete and one partial under CT-based assessment. A separate PET assessment counted five responses, but that secondary measure cannot replace the trial’s primary result. The 95 per cent confidence interval was wide, at 3.4–43.7 per cent.[1]
An older, previously treated patient group
The trial ran at 13 Japanese centres and enrolled nineteen people whose disease had relapsed or resisted earlier chemotherapy. Treatment was given to 18; central pathology review found a different diagnosis in one, excluding that person from efficacy analysis. The treated group’s median age was 73. Among 11 participants with treatment-related adverse events, four experienced events of grade three or higher. There were no reported deaths attributed to treatment. Such a small population cannot rule out uncommon harms or represent all newly diagnosed patients.[1]
A genetic clue still needs a comparison arm
The RHOA p.G17V mutation was present in 11 evaluable patients, including all four who responded; the six without this mutation had no responses. This exploratory subgroup observation raises a question for a future biomarker-selected trial. Without a control arm, the study cannot establish whether the mutation specifically predicts benefit from dasatinib. Interpretation is further limited by subgroup size and the absence of tumour samples after treatment. The genetic signal remains a hypothesis for investigation alongside the overall trial’s failure to meet its response target.[1]
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