Genetic Predictors of Ibrutinib-related Cardiovascular Side Effects in Patients with Chronic Lymphocytic Leukemia

PURPOSE

Patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib are at risk of developing cardiovascular side effects (CVSE). The molecular determinants of CVSEs have not been fully elucidated. We interrogated genetic polymorphisms in the Bruton tyrosine kinase (BTK) signaling pathway for their association with ibrutinib-related CVSEs.

EXPERIMENTAL DESIGN

We conducted a retrospective/prospective observational pharmacogenetic study of 50 patients with newly diagnosed or relapsed CLL who received ibrutinib at a starting daily dose of 420 mg for at least 6 months. CVSEs, primarily atrial fibrillation and hypertension, occurred in 10 patients (20%), of whom 4 discontinued therapy. DNA was isolated from buccal swabs of all 50 patients and genotyped for 40 SNPs in GATA4, SGK1, KCNQ1, KCNA4, NPPA, and SCN5A using a customized next-generation sequencing panel. Univariate and multivariate logistic regression analysis were performed to determine genetic and clinical factors associated with the incidence of ibrutinib-related CVSEs.

RESULTS

GATA4 rs804280 AA (P = 0.043), KCNQ1 rs163182 GG (P = 0.036), and KCNQ1 rs2237895 AA (P = 0.023) genotypes were univariately associated with ibrutinib-related CVSEs. On the basis of multivariate analysis, a high genetic risk score, defined as the presence of at least two of these genotypes, was associated with 11.5-fold increased odds of CVSEs (P = 0.019; 95% confidence interval, 1.79-119.73).

CONCLUSIONS

Our findings suggest possible genetic determinants of ibrutinib-related CVSEs in CLL. If replicated in a larger study, pretreatment pharmacogenetic testing for GATA4 and KCNQ1 polymorphisms may be a useful clinical tool for personalizing treatment selection for CLL and/or instituting early risk mitigation strategies.

Identification of genetic markers associated with ibrutinib-related cardiovascular toxicity

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Background: Cardiovascular side effects (CVSEs: atrial fibrillation, hypertension, etc.) are common in patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib and often lead to dose reductions or discontinuation. However, the etiology of ibrutinib related CVSEs has not been elucidated. This study sought to interrogate the association between ibrutinib related CVSEs and polymorphisms in genes of the Bruton Tyrosine Kinase (BTK) signaling pathway (identified through Ingenuity Pathway Analysis) Methods: Newly diagnosed and relapsed patients with CLL who underwent treatment with ibrutinib between December 2019 and November 2020 at Levine Cancer Institute were identified. Buccal swabs were collected through an IRB approved specimen collection protocol. Data extraction included: demographics, CLL stage, cytogenetics, previous treatments, ibrutinib start dates and dose, drug related SEs, and other medications. DNA isolated from buccal swabs was genotyped for 40 single nucleotide polymorphisms (SNPs) in GATA4, SGK1, KCNQ1, KCNA4, NPPA and SCN5A genes using a custom NGS panel. Logistic regression analysis evaluated the association between SNPs and CVSEs. Results: In 50 evaluable patients, the median age was 71 years (range:48-90) and 50% received frontline ibrutinib monotherapy. CVSEs occurred in 20% of patients (n=10). In univariate analysis, 4 SNPs in 3 genes were significantly associated with CVSEs (Table). Because the genes were in the same pathway, a genetic risk score was developed which indicated that patients with at least 2 SNPs had a 12-fold increase in risk of CVSEs (Table). Conclusions: Our findings provide insights into the genetic determinants of ibrutinib related CVSEs. If replicated in a larger study, this will facilitate utility of pharmacogenetic testing (for GATA4, KCNQ1 and KCNA5 polymorphisms ) as a clinical tool to individualize ibrutinib treatment.[Table: see text]

Patient navigation plus hospital at home to improve COVID-19 outcomes for cancer patients

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Background: Reports suggested cancer patients were at greater risk for increased morbidity and mortality from COVID-19. A process to mitigate these risks was established at Levine Cancer Institute (LCI) in partnership with Atrium Health’s (AH) Hospital at Home (HAH) initiative. This virtual health navigation process employed expertise from the departments of Hematologic Oncology and Blood Disorders, Oncology, and Supportive Oncology, including a specialized nurse navigation team, to rapidly identify COVID-19 positive LCI patients, monitor them under physician supervision, and escalate care as needed with AH HAH program. Methods: AH Information Services created an automated list of LCI COVID-19 positive patients with a daily database. Each patient was reviewed by a nurse navigator. Review included hematologic or oncologic diagnosis, outpatient or inpatient status, and any COVID-19 symptoms. Once a malignant diagnosis was confirmed, a diagnosis-specific navigator contacted and screened the patient with a COVID assessment tool. Documentation was forwarded to the primary oncologist/hematologist. The tool scored patients for surveillance and treatment needs. A score of 0-2 prompted phone assessment every 48-72 hours, and score of 3-5 required every 24-48 hour calls with physician involvement when appropriate. If score of ≥6, care was escalated to LCI nurse/physician for admission to AH acute care HAH or conventional inpatient admission. Results: From inception on 3/20/2020 to data review date of 12/2/2020, 974 LCI patients were identified as COVID-19 positive and reviewed for nurse navigation (Table). Of the 974, 488 were navigated. Given limited resources, patients with benign conditions were not assigned a navigator, though a similar process was created for sickle cell disease. Of the 974, 75 are now deceased. Only 25 are deceased among the 488 navigated. Conclusions: The COVID-19 pandemic presented unprecedented circumstances to our patients and their clinicians. LCI expeditiously put policies and procedures in place to mitigate the intersection of COVID-19 and cancer. The multidisciplinary response strategy liaising between AH HAH and LCI followed, assessed, and assisted LCI COVID-19 positive patients. With our embedded nurse navigation team’s specialized attention along with enhanced physician oversight and close collaboration with AH HAH, opportunities for care escalation or adjustments in cancer-focused care were promptly identified. Analysis is ongoing to elucidate the lower mortality rate observed among navigated patients.[Table: see text]

Outcomes in minority patients (pt) with aggressive B cell lymphoma (BCL) if optimally managed with equal access to care and nurse navigation (NN)

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Background: Aggressive BCL is curable but previous studies have shown that minorities have inferior survival, partly due to socioeconomic barriers and poor access to care. NN programs are designed to reduce barriers to care via various methods. We present disease characteristics, treatment, and outcomes of Caucasian (C) & non-Caucasian (NC) pts with aggressive BCL at Levine Cancer Institute which has an active NN program. Methods: We collected demographic, insurance, disease characteristics, treatment, and outcomes for pts with aggressive BCL [diffuse large B cell lymphoma (DLBCL), primary mediastinal B cell lymphoma (PMBCL), or high grade B cell lymphoma (HGL)] between Jan 2016 and Jun 2019. Race (C or NC) was self-reported. NN encounters were characterized as low intensity (basic needs) or high (moderate/high needs). OS and PFS were calculated using Kaplan Meier. Demographics were compared using Fisher's Exact tests. Results: 204 pts (186 = DLBCL, 14 = PMBCL, 4 = HGL) were included (NC = 47; C = 157). NC were younger at diagnosis (median age 56 vs 62 yrs, p = 0.03) and more likely to be uninsured/Medicaid (26% vs 4%, p < 0.0001). There were no significant differences in prognostic scores (44% vs 50% R-IPI score 3-5, p = 0.5), incidence of double hit (11% vs 13%, p = 0.8), frontline rituximab/anthracycline containing chemotherapy (98% vs 96%, p = 0.9), and incidence of relapsed/refractory (R/R) disease (40% vs 37%, p = 0.7) for NC compared to C. For R/R BCL, similar % of pts underwent hematopoietic stem cell transplant (SCT) (32% NC vs 28% C, p = 0.8) or CAR-T cell therapy (16% NC vs 19% C, p = 0.9). Enrollment in clinical trials was comparable (17% NC vs 14% C, p = 0.6). The % of pts receiving NN was similar (81% NC, 87% C, p = 0.4) but NC had higher intensity NN encounters (42% vs 21%, p = 0.01). With median follow up of 35 mo, OS and PFS were comparable between both groups. The 2 yr OS was 81% for NC and 76% for C, p = 0.3; 2 yr PFS was 62% for NC and 64% for C, p = 0.8. Conclusions: We show equivalent survival between Caucasian and non-Caucasian pts with aggressive BCL. Disease biology and treatment patterns--including access to SCT, CAR-T and clinical trials--were similar in both groups. Differences in insurance coverage favored Caucasians. Similar proportion of pts in both groups received nurse navigation, but non-Caucasian pts had higher intensity navigation needs. Providing equal access to care and availability of an active nurse navigation program may overcome racial heath disparities. This study has implications for national health policy.

Myc enhances B-cell receptor signaling in precancerous B cells and confers resistance to Btk inhibition

Dysregulation of the oncogenic transcription factor MYC induces B cell transformation and is a driver for B cell non-Hodgkin lymphoma (B-NHL). MYC overexpression in B-NHL is associated with more aggressive phenotypes and poor prognosis. Although genomic studies suggest a link between MYC overexpression and B cell receptor (BCR) signaling molecules in B-NHL, signaling pathways essential to Myc-mediated B-cell transformation have not been fully elucidated. We utilized intracellular phospho-flow cytometry to investigate the relationship between Myc and BCR signaling in pre-malignant B cells. Utilizing the Eμ-myc mouse model, where Myc is overexpressed specifically in B cells, both basal and stimulated BCR signaling were increased in precancerous B lymphocytes from Eμ-myc mice compared to wild-type littermates. B cells overexpressing Myc displayed constitutively higher levels of activated CD79α, Btk, Plcγ2, and Erk1/2. Notably, Myc overexpressing B cells maintained elevated BCR signaling despite treatment with ibrutinib, a Bruton’s tyrosine kinase inhibitor. Furthermore, PI3K/Akt pathway signaling was also increased in Eμ-myc B cells, and this increase was partially suppressed with ibrutinib. Additionally, experiments with Btk-null B cells revealed off-target effects of ibrutinib on BCR signaling. Our data show that in pre-malignant B cells, Myc overexpression is sufficient to activate BCR and PI3K/Akt signaling pathways and further enhances signaling following BCR ligation. Therefore, our results indicate precancerous B cells have already acquired enhanced survival and growth capabilities prior to transformation, and that elevated MYC levels confer resistance to pharmacologic inhibitors of BCR signaling, which has significant implications for B-NHL treatment.