Table summary of death rate dose-response coefficients.

Two-arm, randomized, open-label trial designed to evaluate the efficacy and safety of bosutinib alone compared to imatinib alone in subjects newly diagnosed with chronic phase Chronic Myelogenous Leukemia (CML). The primary endpoint is cytogenetic response rate at one year.

Introduction: The treatment of relapsed or refractory (R/R) Philadelphia chromosome (Ph)–positive acute lymphoblastic leukemia (ALL) remains challenging after failure to several tyrosine kinase inhibitors. This study evaluated the clinical outcomes of ponatinib in a real-world cohort with R/R Ph-positive ALL, including those treated at the stage of measurable residual disease (MRD) relapse.

Methods: We retrospectively analyzed 79 adults with R/R Ph-positive ALL treated with ponatinib monotherapy. At the start of treatment, 55 patients (69.6%) were in hematologic relapse, while 24 (30.4%) were in MRD relapse. We evaluated CR rate, MRD response, survival outcomes, and predictors of response and survival according to various clinical and genetic parameters.

Results: CR was achieved in 48 (60.7%) patients, and 22 of 46 with MRD data (47.8%) achieved CMR. Ponatinib initiation at MRD relapse was associated with higher odds of better molecular response. In multivariate analysis, age under 60 and MRD response better than MMR were linked to improved OS. However, 2-year OS remained poor at 29.5% (95% CI: 18.9–40.9%). Allo-HCT was performed in 38 patients (48.1%), with a 2-year post-transplant OS of 29.1% (95% CI: 12.9–47.6%). Prior allo-HCT was associated with inferior OS and DFS.

Conclusion: Ponatinib achieved an acceptable CR rate and MRD response in R/R Ph-positive ALL, but long-term survival remained poor despite allo-HCT. These results support earlier use of ponatinib in the salvage setting and highlight the need for combination strategies to overcome the limited durability of monotherapy in patients with R/R Ph-positive ALL.

SARS-CoV-2 is the viral agent responsible for the pandemic that in the first months of 2020 caused about 400,000 deaths. Among compounds proposed to fight the SARS-CoV-2-related disease (COVID-19), tyrosine kinase inhibitors (TKIs), already effective in Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myeloid leukemia (CML), have been proposed on the basis of their antiviral action already demonstrated against SARS-CoV-1. Very few cases of COVID-19 have been reported in Ph+ ALL and in CML Italian cohorts; authors suggested that this low rate of infections might depend on the use of TKIs, but the biological causes of this phenomenon remain unknown. In this study, the CML model was used to test if TKIs would sustain or not the viral replication and if they could damage patient immunity. Firstly, the infection and replication rate of torquetenovirus (TTV), whose load is inversely proportional to the host immunological control, have been measured in CML patients receiving nilotinib. A very low percentage of subjects were infected at baseline, and TTV did not replicate or at least showed a low replication rate during the follow-up, with a mean load comparable to the measured one in healthy subjects. Then, after gene expression profiling experiments, we found that several “antiviral” genes, such as CD28 and IFN gamma, were upregulated, while genes with “proviral” action, such as ARG-1, CEACAM1, and FUT4, were less expressed during treatment with imatinib, thus demonstrating that TKIs are not detrimental from the immunological point of view. To sum up, our data could offer some biological explanations to the low COVID-19 occurrence in Ph+ ALL and CML patients and sustain the use of TKIs in COVID-19, as already proposed by several international ongoing studies.