Interferon-α Revisited: Individualized Treatment Management Eased the Selective Pressure of Tyrosine Kinase Inhibitors on BCR-ABL1 Mutations Resulting in a Molecular Response in High-Risk CML Patients.

Bone marrow transplantation or ponatinib treatment are currently recommended strategies for management of patients with chronic myeloid leukemia (CML) harboring the T315I mutation and compound or polyclonal mutations. However, in some individual cases, these treatment scenarios cannot be applied. We used an alternative treatment strategy with interferon-α (IFN-α) given solo, sequentially or together with TKI in a group of 6 cases of high risk CML patients, assuming that the TKI-independent mechanism of action may lead to mutant clone repression. IFN-α based individualized therapy decreases of T315I or compound mutations to undetectable levels as assessed by next-generation deep sequencing, which was associated with a molecular response in 4/6 patients. Based on the observed results from immune profiling, we assumed that the principal mechanism leading to the success of the treatment was the immune activation induced with dasatinib pre-treatment followed by restoration of immunological surveillance after application of IFN-α therapy. Moreover, we showed that sensitive measurement of mutated BCR-ABL1 transcript levels augments the safety of this individualized treatment strategy

Summary of sequential lines of treatment, therapy responses and mutation status.

<p>Summary of sequential lines of treatment, therapy responses and mutation status.</p

Patient’s characteristics.

<p>Patient’s characteristics.</p

Dynamics of total and mutated BCR-ABL1 transcript levels.

<p>(A) Patient no 1: The patient achieved MMR on solo IFN-α and maintained MMR for 88 months; the T315I mutation was persistently undetectable for 62 months due to the overall low levels of total BCR-ABL1 transcripts. (B) Patient no 2: Compound mutations M351T/F317L (100%) developed after sequential therapy with imatinib and dasatinib. The patient has now been on IFN-α/nilotinib therapy with undetectable mutations for 29 months. MR⁵ was achieved on the 15^th month of the combined treatment. (C) Patient no 3: Poor compliance to imatinib treatment within the 24^th– 30^th month; the T315I mutation burden decreased on solo IFN-α therapy down to undetectable levels after the combination of IFN-α and nilotinib. The patient achieved MR⁵ in the 22^nd month from IFN-α treatment initiation. (D) Patient no 4: The T315I mutation decreased on solo IFN-α therapy and was not detected for the subsequent 46 months on solo nilotinib therapy. The relatively slow reduction of the BCR-ABL1 transcript level and MMR achievement might have been caused by a problematic compliance to nilotinib. (E) Patient no 5: The T315I mutation decreased on solo IFN-α therapy, but the F317L and E255V mutations appeared and expanded. Death of this patient was related to lung tuberculosis. (F) Patient no 6: IFN-α therapy did not contribute to the T315I reduction and response improvement. Therefore, the patient has been switched to ponatinib with CCgR achievement after 7 months from ponatinib treatment initiation. IMA-imatinib, NILO-nilotinib, DASA-dasatinib, IFN-α –interferon alpha, HU-hydroxyurea, PONA-ponatinib. Note: A mutation burden of 0% represented undetectable levels of mutated BCR-ABL1 transcripts when the sequencing depth was 1,000 to 8,000 sequence reads per each nucleotide position.</p

Flow cytometry results.

<p>Flow cytometry results.</p

ENIGMA CHEK2gether Project : a comprehensive study identifies functionally impaired CHEK2 germline missense variants associated with increased breast cancer risk

Purpose: Germline pathogenic variants in CHEK2 confer moderately elevated breast cancer risk (odds ratio, OR ∼ 2.5), qualifying carriers for enhanced breast cancer screening. Besides pathogenic variants, dozens of missense CHEK2 variants of uncertain significance (VUS) have been identified, hampering the clinical utility of germline genetic testing (GGT). Experimental Design: We collected 460 CHEK2 missense VUS identified by the ENIGMA consortium in 15 countries. Their functional characterization was performed using CHEK2-complementation assays quantifying KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1–CHEK2-knockout cells. Concordant results in both functional assays were used to categorize CHEK2 VUS from 12 ENIGMA case–control datasets, including 73,048 female patients with breast cancer and 88,658 ethnicity-matched controls. Results: A total of 430/460 VUS were successfully analyzed, of which 340 (79.1%) were concordant in both functional assays and categorized as functionally impaired (N = 102), functionally intermediate (N = 12), or functionally wild-type (WT)–like (N = 226). We then examined their association with breast cancer risk in the case–control analysis. The OR and 95% CI (confidence intervals) for carriers of functionally impaired, intermediate, and WT-like variants were 2.83 (95% CI, 2.35–3.41), 1.57 (95% CI, 1.41–1.75), and 1.19 (95% CI, 1.08–1.31), respectively. The meta-analysis of population-specific datasets showed similar results. Conclusions: We determined the functional consequences for the majority of CHEK2 missense VUS found in patients with breast cancer (3,660/4,436; 82.5%). Carriers of functionally impaired missense variants accounted for 0.5% of patients with breast cancer and were associated with a moderate risk similar to that of truncating CHEK2 variants. In contrast, 2.2% of all patients with breast cancer carried functionally wild-type/intermediate missense variants with no clinically relevant breast cancer risk in heterozygous carriers