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Background:We have previously reported that ∼50% of CLL patients (pts) experience rapid flare of disease when they discontinue ibrutinib therapy due to progression of disease (CLL or Richter's transformation [RT]) (Hampel et al, JCO suppl, 2018). This lead to the clinical practice of overlapping venetoclax with ibrutinib for combination therapy in this setting to prevent ibrutinib withdrawal.Aims:To evaluate the role of continuing ibrutinib beyond the start of salvage venetoclax in pts who have progression of disease on ibrutinib monotherapy, both in preventing ibrutinib withdrawal associated with ibrutinib discontinuation and in disease response.Methods:We identified all CLL pts at Mayo Clinic (3/2017–11/2018) who had disease progression on ibrutinib therapy, where venetoclax was added as subsequent treatment while ibrutinib was continued. CLL‐specific characteristics, treatment timeline and toxicities, and disease course following combination therapy were ascertained. All pts started venetoclax according to the weekly ramp‐up per the package instructions.Results:Eighteen pts treated with the addition of venetoclax to ibrutinib therapy were identified; indications were CLL progression (n = 13) and RT (n = 5). BTK or PLCG2 mutations were present in 8/13 pts. Median duration of follow‐up was 9.6 months after the start of combination therapy.The target venetoclax dose was reached by 5 weeks in 13 pts; reasons for delaying or stopping dose escalation included diarrhea (n = 2), sepsis (n = 2), and neutropenia (n = 1). No patient experienced a disease flare during venetoclax ramp‐up.The median duration of combination ibrutinib and venetoclax therapy was 3 months (range, 0–14 months). Of 18 pts who started combination therapy with ibrutinib and venetoclax, ibrutinib was discontinued in 10 pts. Reasons included hematopoietic stem cell transplant (n = 2), planned stop after adequate disease control (n = 4), financial reasons (n = 1), toxicity (neutropenia n = 1, immune thrombocytopenia/bleeding risk n = 1), and death (n = 1). Only 1 patient experienced ibrutinib withdrawal, which occurred following planned discontinuation after clinical complete response (CR) with a 41 day overlap and toleration of venetoclax 400 mg daily; management with re‐initiation of ibrutinib was effective in regaining disease control. Of 9 pts who stopped ibrutinib, 4 pts had a slow taper over 2–8 weeks, and 2 pts also received corticosteroids at the time of ibrutinib discontinuation.Among the other 8 pts who did not discontinue ibrutinib, 6 pts remain on the combination with venetoclax (median duration 6.5 months, range 3–14 months), and 2 pts continued on ibrutinib following venetoclax discontinuation due to disease progression (both pts received further combination of ibrutinib with multi‐agent chemotherapy).The overall response rate (ORR) to combination therapy with ibrutinib and venetoclax was 81% (CR/clinical CR n = 9, partial response n = 4, stable disease n = 1, and primary refractory disease n = 2). The duration of combination therapy was <4 weeks in 2 pts, precluding response assessment. The estimated 12‐month event‐free survival was 54% (95% CI 33–87%), and the estimated 12‐month overall survival from start of combination therapy was 79% (95% CI 60–100%); see Figure 1.Summary/Conclusion:Among CLL pts who develop progression of disease on ibrutinib monotherapy, continued ibrutinib therapy with addition of venetoclax was feasible, ameliorated ibrutinib withdrawal, and was associated with high ORR.image

Abstract Introduction: Laboratory studies have demonstrated that zinc and zinc transporters play important roles in the development of urological cancers, including prostate, bladder, and renal cell cancer. To date however, there have been no efforts to evaluate whether germline variation in zinc transporter genes alter the risk of developing these cancers. Motivated by this, we evaluated associations of known variants in zinc transporter genes with risk of prostate, bladder, and renal cell cancer using three NCI Genome Wide Association Study (GWAS) data sets downloaded from dbGaP. Methods: Data consisted of GWAS data from the PLCO Screening Trial (prostate; 1172 cases, 1157 controls); Bladder Cancer study (3527 cases, 5119 controls); and Renal Cancer study (1453 cases, 3531 controls). All genotyped variants in 10 ZNT family genes (ZNT1-ZNT10) and 14 ZIP family genes (ZIP1-ZIP14) in each data set were analyzed by logistic regression models to evaluate the association of each variant with risk of developing prostate, bladder, and renal cancer, respectively. We evaluated these associations in a univariable setting, after adjusting for available covariates, such as age and gender. Correction for multiple comparisons used Max T permutation tests. Results: One variant in ZIP11, rs8081059, was associated with increased risk of renal cancer (OR=1.28, 95% CI= 1.13-1.45; corrected p= 0.049). Another ZIP11 variant, rs11871756, was associated with an increased risk of bladder cancer risk (OR=1.43, 95% CI 1.24-1.63; corrected p=0.0002). We also found three variants in ZIP11 associated with a decreased risk of bladder cancer: rs11077654 (OR=0.76, 95% CI 0.68-0.85; corrected p=0.001), rs9913017 (OR=0.76, 95% CI= 0.68-0.85; corrected p=0.002), and rs4969054 (OR=0.78, 95% CI 0.69-0.88; corrected p=0.02). Interestingly, these three protective variants are within the same LD block. There were no associations between zinc transporter variants and prostate cancer risk. Conclusion: We report for the first time that specific genetic variants of a zinc transporter gene, ZIP11, are associated with risk of renal and bladder cancer. If validated in larger, more focused studies, further investigations are warranted to explore the functional significance of ZIP11 in these two cancers. Citation Format: Lang Wu, Kari G. Rabe, Alexander S. Parker, Gloria M. Petersen. ZIP11 and susceptibility to renal and bladder cancer. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A52.

Abstract Background: Pancreatic cancer is the fourth-leading cause of cancer death in both men and women in the United States. The currently identified common susceptibility loci account for a small fraction of estimated heritability. We sought to estimate overall heritability of pancreatic cancer and partition the heritability by variant frequencies and functional annotations. Methods: Analysis using the genome-based restricted maximum likelihood method (GREML) was conducted on Pancreatic Cancer Case-Control Consortium (PanC4) genome-wide association study (GWAS) data from 3,568 pancreatic cancer cases and 3,363 controls of European Ancestry. Results: Applying linkage disequilibrium- and minor allele frequency-stratified GREML (GREML-LDMS) method to imputed GWAS data, we estimated the overall heritability of pancreatic cancer to be 21.2% (SE = 4.8%). Across the functional groups (intronic, intergenic, coding, and regulatory variants), intronic variants account for most of the estimated heritability (12.4%). Previously identified GWAS loci explained 4.1% of the total phenotypic variation of pancreatic cancer. Mutations in hereditary pancreatic cancer susceptibility genes are present in 4% to 10% of patients with pancreatic cancer, yet our GREML-LDMS results suggested these regions explain only 0.4% of total phenotypic variance for pancreatic cancer. Conclusions: Although higher than previous studies, our estimated 21.2% overall heritability may still be downwardly biased due to the inherent limitation that the contribution of rare variants in genes with a substantive overall impact on disease are not captured when applying these commonly used methods to imputed GWAS data. Impact: Our work demonstrated the importance of rare and common variants in pancreatic cancer risk.

Ex vivo CRISPR/Cas9‐mediated gene editing in hepatocytes using homology‐directed repair (HDR) is a potential alternative curative therapy to organ transplantation for metabolic liver disease. However, a major limitation of this approach in quiescent adult primary hepatocytes is that nonhomologous end‐joining is the predominant DNA repair pathway for double‐strand breaks (DSBs). This study explored the hypothesis that ex vivo hepatocyte culture could reprogram hepatocytes to favor HDR after CRISPR/Cas9‐mediated DNA DSBs. Quantitative PCR (qPCR), RNA sequencing, and flow cytometry demonstrated that within 24 hours, primary mouse hepatocytes in ex vivo monolayer culture decreased metabolic functions and increased expression of genes related to mitosis progression and HDR. Despite the down‐regulation of hepatocyte function genes, hepatocytes cultured for up to 72 hours could robustly engraft in vivo. To assess functionality long‐term, primary hepatocytes from a mouse model of hereditary tyrosinemia type 1 bearing a single‐point mutation were transduced ex vivo with two adeno‐associated viral vectors to deliver the Cas9 nuclease, target guide RNAs, and a 1.2‐kb homology template. Adeno‐associated viral Cas9 induced robust cutting at the target locus, and, after delivery of the repair template, precise correction of the point mutation occurred by HDR. Edited hepatocytes were transplanted into recipient fumarylacetoacetate hydrolase knockout mice, resulting in engraftment, robust proliferation, and prevention of liver failure. Weight gain and biochemical assessment revealed normalization of metabolic function. Conclusion: The results of this study demonstrate the potential therapeutic effect of ex vivo hepatocyte‐directed gene editing after reprogramming to cure metabolic disease in a preclinical model of hereditary tyrosinemia type 1.

The prevalence, clinicopathologic correlates, and outcomes of previously untreated chronic lymphocytic leukemia (CLL) patients with IGH‐BCL2 and IGH‐BCL3 translocations are not well known. Using the Mayo Clinic CLL database, we identified patients seen between March 1, 2002 and September 30, 2016 who had FISH testing performed within 3 years of CLL diagnosis. The prognostic profile, time to first therapy (TTT), and overall survival (OS) of patients with IGH‐BCL2 and IGH‐BCL3 translocation were compared to patients without these abnormalities (non‐IGH group). Of 1684 patients who met the inclusion criteria, 38 (2.2%) had IGH‐BCL2, and 16 (0.9%) had IGH‐BCL3 translocation at diagnosis. Patients with IGH‐BCL3 translocation were more likely to have high and very‐high CLL‐International Prognostic Index, compared to patients with IGH‐BCL2 translocation and the non‐IGH group. The 5‐year probability of requiring therapy was significantly higher for IGH‐BCL3 compared to IGH‐BCL2 and non‐IGH groups (84% vs 33% vs 29%, respectively, P < 0.0001). The 5‐year OS was significantly shorter for IGH‐BCL3 compared to IGH‐BCL2 and non‐IGH groups (45% vs 89% vs 86%, respectively, P < 0.0001). On multivariable analyses, IGH‐BCL3 translocation was associated with a shorter TTT (hazard ratio [HR] = 2.7; P = 0.005) and shorter OS (HR = 5.5; P < 0.0001); IGH‐BCL2 translocation did not impact TTT and OS. In conclusion, approximately 3% of all newly diagnosed CLL patients have either an IGH‐BCL2 or IGH‐BCL3 translocation. Patients with IGH‐BCL3 translocations have a distinct prognostic profile and outcome. These results support the inclusion of an IGH probe during the routine evaluation of FISH abnormalities in newly diagnosed CLL.