Serotonin re-uptake transporter gene polymorphisms are associated with imatinib-induced diarrhoea in chronic myeloid leukaemia patients.

Tyrosine kinase inhibitors (TKIs), the treatment of choice for chronic myeloid leukaemia (CML), can cause lower gastrointestinal (GI) toxicity which is manifested as diarrhoea. The mechanisms are not fully understood. The enteroendocrine signalling compound, serotonin (5-HT), is important for regulating peristaltic motion, fluid secretion and visceral hypersensitivity in the GI tract, and has been implicated in diseases such as irritable bowel syndrome. In this study, we have evaluated whether TKI-induced diarrhoea may be related to variation in the serotonin re-uptake transporter (SERT) gene. CML patients with and without diarrhoea on the SPIRIT2 trial (imatinib, n = 319; and dasatinib, n = 297) were genotyped for the promoter 5-HTTLPR, intron 2 VNTR and rs25531 polymorphisms by PCR-based methods. Diarrhoea was more prevalent in imatinib, than in dasatinib treated patients (P = 0.015), which when stratified by gender was seen to be driven by female patients (P = 0.036). Logistic regression analysis revealed that age, and the dominant HTTLPR with the rs25531 single nucleotide polymorphism (SNP) model, explained the occurrence of diarrhoea in ~10% of imatinib-treated female CML patients. These data suggest SERT polymorphisms influence imatinib-induced diarrhoea but not that of dasatinib

Recurrent histone mutations in T-cell acute lymphoblastic leukaemia.

Mutations affecting key modifiable histone type 3 (H3; Supplementary Table 1) residues are frequent oncogenic events in certain solid tumours (Feinberg, et al 2016), and have also recently been implicated in a subset of acute myeloid leukaemia (AML)(Lehnertz, et al 2017). Here, we systematically reviewed the somatic mutations in >20,000 cancer specimens to identify tumours harbouring H3 mutations. In a subset of T-cell acute lymphoblastic leukaemia (T-ALL) we identified non-methionine mutations of the key modifiable H3 residues, lysine (K) 27 and 36

Triple Negative Breast Cancers Have a Reduced Expression of DNA Repair Genes

DNA repair is a key determinant in the cellular response to therapy and tumor repair status could play an important role in tailoring patient therapy. Our goal was to evaluate the mRNA of 13 genes involved in different DNA repair pathways (base excision, nucleotide excision, homologous recombination, and Fanconi anemia) in paraffin embedded samples of triple negative breast cancer (TNBC) compared to luminal A breast cancer (LABC). Most of the genes involved in nucleotide excision repair and Fanconi Anemia pathways, and CHK1 gene were significantly less expressed in TNBC than in LABC. PARP1 levels were higher in TNBC than in LABC. In univariate analysis high level of FANCA correlated with an increased overall survival and event free survival in TNBC; however multivariate analyses using Cox regression did not confirm FANCA as independent prognostic factor. These data support the evidence that TNBCs compared to LABCs harbour DNA repair defects

A randomised Phase II trial of Hydroxychloroquine and Imatinib versus Imatinib alone for patients with Chronic Myeloid Leukaemia in Major Cytogenetic Response with residual disease

In chronic-phase chronic myeloid leukaemia (CP-CML), residual BCR-ABL1+ leukaemia stem cells are responsible for disease persistence despite TKI. Based on in vitro data, CHOICES (CHlorOquine and Imatinib Combination to Eliminate Stem cells) was an international, randomised phase II trial designed to study the safety and efficacy of imatinib (IM) and hydroxychloroquine (HCQ) compared with IM alone in CP-CML patients in major cytogenetic remission with residual disease detectable by qPCR. Sixty-two patients were randomly assigned to either arm. Treatment ‘successes’ was the primary end point, defined as ≥0.5 log reduction in 12-month qPCR level from trial entry. Selected secondary study end points were 24-month treatment ‘successes’, molecular response and progression at 12 and 24 months, comparison of IM levels, and achievement of blood HCQ levels >2000 ng/ml. At 12 months, there was no difference in ‘success’ rate (p = 0.58); MMR was achieved in 80% (IM) vs 92% (IM/HCQ) (p = 0.21). At 24 months, the ‘success’ rate was 20.8% higher with IM/HCQ (p = 0.059). No patients progressed. Seventeen serious adverse events, including four serious adverse reactions, were reported; diarrhoea occurred more frequently with combination. IM/HCQ is tolerable in CP-CML, with modest improvement in qPCR levels at 12 and 24 months, suggesting autophagy inhibition maybe of clinical value in CP-CML

De-escalation of tyrosine kinase inhibitor dose in patients with chronic myeloid leukaemia with stable major molecular response (DESTINY): an interim analysis of a non-randomised, phase 2 trial

BACKGROUND: Discontinuation of tyrosine kinase inhibitor (TKI) therapy is feasible for some patients with chronic myeloid leukaemia (CML) with deep molecular responses, defined as stable MR4 (BCR-ABL1/ABL1 ratio 0.1%) on two consecutive samples. The study endpoint is the proportion of patients who lose their MMR on de-escalation and regain MMR on TKI resumption. The trial was registered at https://clinicaltrials.gov/ as NCT 01804985.FINDINGS: During the 12 months of half-dose therapy, 12 patients had molecular recurrence, all of whom regained MMR within 4 months of full dose TKI resumption. Recurrence was lower in the MR4 cohort (3 of 121 evaluable patients; 2.5%, 90% CI: 0.2-4.8%) than in the MMR cohort (9 of 48 evaluable patients; 18.8%, 90% CI: 9.5-28%) (p = 0.0007), but was unrelated to prior TKI or TKI therapy duration. Many adverse events improved during the first 3 months of de-escalation, though not thereafter. Overall, de-escalation saved 46.7% from an expected TKI budget (without de-escalation) of £4,156,969.INTERPRETATION: TKI de-escalation is safe for the vast majority of patients with excellent responses to TKI therapy, and is associated with improvement in symptoms and significant financial savings. The data imply that lower TKI doses may maintain responses in these patients

Structural studies on the human Vk locus and on immunoglobulin gene rearrangements in leukaemic cells

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