Key Points: UDS demonstrated that BCR-ABL KD mutations detectable with conventional methods may just be the tip of the iceberg. The information provided by conventional Sanger sequencing may not always be sufficient to predict responsiveness to a given TKI.

The most frequent BCR‐ABL1 fusion transcripts in chronic myeloid leukemia (CML) are the e13a2 (b2a2) and the e14a2 (b3a2) ones. In the imatinib era few studies addressing the prognostic significance of the BCR‐ABL1 transcript type in early chronic phase CML have been published. Overall, these studies suggest that in e14a2 patients the response to imatinib is faster and deeper. To evaluate if the BCR‐ABL1 transcript type (e13a2 compared to e14a2) affect the response to imatinib and the clinical outcome in newly diagnosed adult CML patients, 559 patients enrolled in 3 prospective studies (NCT00514488, NCT00510926, observational study CML/023) were analyzed. A qualitative PCR was performed at baseline: 52% patients had a e14a2 transcript, 37% a e13a2 transcript, 11% co‐expressed both transcripts and 1% had other rare transcripts. The median follow‐up was 76 months (95% of the patients had at least a 5‐year observation). The complete cytogenetic response rates were comparable in e14a2 and e13a2 patients. The median time to MR^3.0(6 and 12 months) and MR^4.0(41 and 61 months) was significantly shorter for e14a2 patients compared to e13a2 patients, with a higher cumulative probability of MR^3.0(88% and 83%,P < .001) and MR^4.0(67% and 52%,P = .001). The 7‐year overall survival (90% and 83%,P = .017), progression‐free survival (89% and 81%,P = .005) and failure‐free survival (71% and 54%,P < .001) were significantly better in patients with e14a2 transcript. In conclusion, patients with e13a2 transcript had a slower molecular response with inferior response rates to imatinib and a poorer long‐term outcome.

Nilotinib is a second-generation tyrosine kinase inhibitor that has been approved for the first-line treatment of chronic-phase chronic myeloid leukemia, based on the results of a prospective randomized study of nilotinib versus imatinib (ENESTnd). Apart from this registration study, very few data are currently available on first-line nilotinib treatment. We report here the long-term, 6-year results of the first investigator-sponsored, GIMEMA multicenter phase 2, single-arm trial with nilotinib 400 mg twice daily as first-line treatment in 73 patients with chronic-phase chronic myeloid leukemia. Six-year overall survival and progression-free survival rates were 96%, with one death after progression to blast phase. At 6 years, 75% of the patients were still on nilotinib. The cumulative incidence of major molecular response was 98%; only one patient had a confirmed loss of major molecular response. The cumulative incidence of deep molecular response (MR 4.0) was 76%. Deep molecular response was stable (≥2 years) in 34% of these patients. Cardiovascular adverse events, mainly due to arterial thrombosis, occurred in 11/73 patients (15%), after 24 to 76 months of therapy. They were more frequent in elderly patients, and in those with baseline cardiovascular risk factors. None was fatal, although there was a relevant morbidity. This is the study with the longest follow-up of a high dose of nilotinib (400 mg twice daily): it highlights the high efficacy and the cardiovascular toxicity of the drug (CTG.NCT.00481052).

The new Regulation (EU) No. 536/2014 for clinical trials of medicinal products for human is part of a European regulatory framework in which the European Commission has wished to give a strong impetus to scientific research and industrial progress. It is a new regulation that fills a series of regulatory gaps in the Clinical Trials through the creation of a uniform framework for the authorization of clinical trials by all interested Member States with a single assessment of the results. The Regulation thus facilitates cross-border cooperation to make the clinical tests wider and encourage the development of special treatments, for example for rare diseases, but above all streamlines the rules on clinical trials across European Union (EU), introducing simplified rules for experimentation so-called 'low level of intervention', on which much has been discussed and still arouses concern, providing for authorized medicines or used off-label in the presence of scientific evidence published on efficacy and safety and to benefit from they will be mainly the pediatric and oncological therapeutic areas. The applications and any communication will be submitted paperlessly via a new electronic EU portal. The complex processing procedures and shorter time limits are to be stressed in comparison to the previously valid regulations. This is a major challenge for all stakeholders, but on the other hand it should contribute to the future role of the EU in the development of innovative medicines.

Specific myeloid-related and inositide-specific gene mutations can be linked to myelodysplastic syndromes (MDS) pathogenesis and therapy. Here, 44 higher-risk MDS patients were treated with azacitidine and lenalidomide and mutations analyses were performed at baseline and during the therapy. Results were then correlated to clinical outcome, overall survival (OS), leukemia-free-survival (LFS) and response to therapy. Collectively, 34/44 patients were considered evaluable for response, with an overall response rate of 76.25% (26/34 cases): 17 patients showed a durable response, 9 patients early lost response and 8 patients never responded. The most frequently mutated genes were ASXL1, TET2, RUNX1, and SRSF2. All patients early losing response, as well as cases never responding, acquired the same 3 point mutations during therapy, affecting respectively PIK3CD (D133E), AKT3 (D280G), and PLCG2 (Q548R) genes, that regulate cell proliferation and differentiation. Moreover, Kaplan–Meier analyses revealed that this mutated cluster was significantly associated with a shorter OS, LFS, and duration of response. All in all, a common mutated cluster affecting 3 inositide-specific genes is significantly associated with loss of response to azacitidine and lenalidomide therapy in higher risk MDS. Further studies are warranted to confirm these data and to further analyze the functional role of this 3-gene cluster.

Cryptic BCR-ABL fusion gene as variant rearrangement in chronic myeloid leukemia: molecular cytogenetic characterization and influence on TKIs therapy Cryptic BCR-ABL fusion gene as variant rearrangement in chronic myeloid leukemia: molecular cytogenetic characterization and influence on TKIs therapy