What is the optimal treatment for biphenotypic acute leukemia? Authors’ reply

First of all we would like to thank Dr. Zheng et al.1 for their interest in our paper published in this issue of Haematologica and for sharing their experience with a cohort of 19 BAL patients. They raised the question “what is the optimal treatment to biphenotypic acute leukemia?” which we are also interested in.

Based on our data and the observation of Dr. Zheng and colleagues, they proposed that remission induction for BAL patients with ALL or ALL-like regimens may lead to higher CR rate than with AML regimens. Here we would like to share some experience and thoughts with our colleagues. Based on our experience and the pathology of BAL, we believe that a combined regimen for both AML and ALL might be the best choice for the induction therapy for BAL, a unique entity with biological and clinical features of both myeloid and lymphoid leukemia. The ALL or ALL-based induction regimens Dr Zheng et al. mentioned, such as DVLD, DVLD+cytarabine in their center or DVP, CDVP, CDVLP, VPDA, VPHA in our department, all included anthracyclines and/or Ara-C. It has already been widely accepted that anthracycline is a main component in the treatment of both AML and ALL. In other words, the protocol described by Zheng et al. should be effective for BAL with both ALL and AML features. On the other hand, AML-type induction regimen did not include the effective component such as steroids for ALL, so the outcome was poor.

During our data analysis, our first conclusions were that it was better to adopt ALL-type regimens such as VPDA than AML-type regimens such as DA. After an extensive exchange of ideas with our colleagues and reviewers during revision of our manuscript, we finally gave up this conclusion since case numbers in our report are too small for statistical analysis and we just left a few comments in the text.

With the above facts in mind, we think that it is too early to draw a conclusion that induction treatment in BAL patients with ALL or ALL-based protocol may lead to higher CR rate than treatment with AML protocol until we can obtain more evidence from a well conducted prospective multi-center clinical trial.