Call, Tim G.

Abstract Background: Angiogenesis has been found to be an important regulator in the disease progression of both solid tumors and hematologic malignancies. In solid tumors, the balance of pro and anti-angiogenic factors appears to be a critical factor in tumorigenesis, with disturbance in favor of angiogenesis promoting tumor growth and metastasis. This observation led to the concept of an “angiogenic switch” where pro-angiogenic influences outweigh anti-angiogenic factors. Patients with CLL have detectable levels of plasma and cellular pro and anti-angiogenic cytokines as well as abnormal neovascularization in the marrow and lymph nodes. Limited studies of pro-angiogenic cytokines have suggested that inter-patient variation in serum/plasma and cellular levels of these markers may have prognostic implications. We evaluated pro- and anti-angiogenic cytokines in a large sample of patients with CLL to evaluate the presence of angiogenic switching and its implications for disease progression. Methods: In a prospective, longitudinal study, we analyzed the serum/plasma, intracellular(determined by flow cytometry), and CLL B cell secreted (24 hour medium values) levels of pro-angiogenic cytokines (VEGF, bFGF) and an anti-angiogenic cytokine (Thrombospondin [TSP]) in 311 patients with previously untreated CLL. VEGF:TSP and bFGF:TSP ratios were calculated to evaluate for evidence of angiogenic switching (higher ratio suggests a pro-angiogenic phenotype). The relationship of angiogenic cytokines to Rai stage, IgVH gene mutation status, % CD38 protein expression, and time to treatment (TTT) from the date of sample were evaluated (median follow-up=11 months). Sequential samples were available on >90% of patients and were evaluated to assess if changes in levels of angiogenic cytokines occurred in patients requiring treatment. Results: Serum, cellular, and secreted levels of VEGF, bFGF, and TSP showed no correlation with Rai stage, IgVH gene mutation (continuous variable), or % expression of CD38 (continuous variable). However, among patients with Rai stage 0-II disease, individuals with lower TSP levels (<75 percentile, p=0.007) or higher bFGF:TSP ratios (continuous variable; p=0.003) had shorter TTT (Figure 1). Similar relationships for a shorter TTT were also observed for secreted TSP levels (p=0.007) and the cellular bFGF:TSP ratio (p=0.009). On analysis of sequential samples, no clear difference in serum, cellular, or secreted levels of VEGF, bFGF, TSP, VEGF:TSP, or bFGF:TSP occurred among those who required treatment. Conclusions: Angiogenic cytokines appear to have prognostic significance in patients with previously untreated early stage CLL. Importantly, we report the original observation that the ratio of bFGF (pro-angiogenic) to TSP (anti-angiogenic) correlates with time to treatment as a continuous variable. This result provides further evidence that angiogenic switching relates to clinical progression in CLL. Longer follow-up of this cohort is needed to fully define the prognostic implications of angiogenic cytokines in CLL and determine if integration of these markers with other prognostic parameters improves risk stratification for early stage patients. Survival According to Serum Thrombospondin Level Survival According to Serum Thrombospondin Level

Abstract Background: Chronic lymphocytic leukemia (CLL) is a lymphoid malignancy with a strong genetic component. There are over 30 common single nucleotide polymorphisms (SNPs) associated with the risk of CLL. Moreover, in the InterLymph Subtypes Project a number of non-genetic exposures have been found to be associated with CLL, including family history (FH), height, history of atopic conditions, UV radiation, and farming exposures. However there has not been a study evaluating the joint effects among these genetic and non-genetic factors with CLL risk. Methods: Using the Mayo Clinic CLL case-control study of 587 newly diagnosed CLL cases and 790 controls, we performed analyses evaluating joint effects of genetic and non-genetic factors. For genetic effects, we computed a polygenetic risk score (PRS), a weighted averaged of the number of risk alleles across 34 SNPs, with the weights being the log of the odds ratio for each SNP. Exposure data was available for 65% of the cases and 79% of the controls. We evaluated individual and joint associations of FH of any hematological malignancy, total sun exposure categorized by quartiles based on the controls, ever living or working on a farm, any atopy, any allergies, asthma, height, and PRSs categorized by quintiles based on the controls. Multivariate logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results: In our preliminary results, the frequency of CLL cases in the upper PRS quintile was 49% while in the lowest quintile only 5%. The PRS has a strong evidence of association with CLL (OR= 3.04, CI =2.20-4.20 for highest versus the middle quintile). When adjusting for PRS, we still found a positive association with FH for any hematological malignancy (OR = 1.90, CI = 1.25-2.88), FH of non-Hodgkin lymphoma (OR = 2.02, CI = 1.08-3.79), and FH of leukemia (OR = 1.73, CI = 0.98-3.07). When stratifying by FH, the upper quintile of the PRS had a 5.85-fold (CI = 1.69-20.3) increased risk of CLL relative to those in the middle quintile in the FH strata, and a 2.65-fold (CI = 1.75-4.01) increased risk in the non-FH strata. After adjusting for PRS, FH and age, there remained an inverse association with sun exposure in the highest quartile (hours per week) (OR = 0.49, CI = 0.31-0.79) and a positive association with height (per 10 cm change) (OR = 1.37, CI = 1.17-1.62), but there were no associations with atopy, any allergies, history of asthma, or farming. No statistical evidence of an interaction among the variables was observed. Conclusions: We found evidence of independent effects among the genetic and non-genetic factors with risk of CLL. Among these factors, the PRS had the largest effect size. Although we did not observe any statistical interactions, larger sample sizes are warranted to fully evaluate these effects on risk of CLL. We are currently increasing our sample size through collaboration with other research groups. Final results will be presented in the meeting. This abstract is also being presented as Poster A06. Citation Format: Geffen Kleinstern, Dennis Robinson, Tim G. Call, Mark Liebow, Silvia de Sanjosé, Yolanda Benavente, James R. Cerhan, Susan L. Slager. Association of environmental risk factors, family history, and polygenic risk scores with chronic lymphocytic leukemia. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr PR03.

Abstract This abstract is being presented as a short talk in the scientific program. A full abstract is printed in the Proffered Abstracts section (PR03) of the Conference Proceedings. Citation Format: Geffen Kleinstern, Dennis Robinson, Tim G. Call, Mark Liebow, Silvia de Sanjosé, Yolanda Benavente, James R. Cerhan, Susan L. Slager. Association of environmental risk factors, family history, and polygenic risk scores with chronic lymphocytic leukemia. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr A06.

Akt is a downstream target of B cell receptor signaling and is a central regulator of CLL cell survival. We aim to investigate the safety and efficacy of the Akt inhibitor MK‐2206 in combination with bendamustine and rituximab (BR) in relapsed and/or refractory CLL in a phase I/II study. A standard phase I design was used with cohorts of three plus three patients to determine the maximum tolerated dose (MTD) of MK‐2206 in combination with BR in relapsed CLL. Single‐agent MK‐2206 (weekly dosed) was administered one‐week in advance before BR on cycle 1 and subsequently was given with BR at the same time for cycle 2‐6. Phase II employed the MTD of MK‐2206 with BR to evaluate safety and efficacy of this study combination. Thirteen relapsed/refractory CLL were treated for maximal 6‐cycle of therapy. The maximum tolerated dose of MK‐2206 was 90 mg by mouth once weekly. The most common grade 3/4 adverse events were neutropenia (46%), febrile neutropenia (23%), rash (15%), diarrhea (15%), and thrombocytopenia (15%). Overall response rate was 92% with a median progression free survival and treatment free survival of 16 and 24 months, respectively. Five patients (38%) achieved complete remission or complete remission with incomplete count recovery, two of whom were MRD negative. The efficacy and tolerability of this combination indicates that Akt inhibition combined with chemoimmunotherapy is a promising novel treatment combination in CLL and deserves further prospective clinical trial.

Although ibrutinib and idelalisib are profound treatment advances, they will dramatically increase individual out-of-pocket and societal costs of caring for patients with CLL.

Purpose To define the optimal dose of Polyphenon E for chronic daily administration and tolerability in patients with chronic lymphocytic leukemia (CLL). Patients and Methods Previously untreated patients with asymptomatic Rai stage 0 to II CLL were eligible for participation. Polyphenon E with a standardized dose of epigallocatechin-3-gallate (EGCG) was administered using the standard phase I design with three to six patients per dose level (range, 400 to 2,000 mg by mouth twice a day). Trough plasma EGCG levels were measured 1 month after initiation of therapy. Response was classified using the National Cancer Institute (NCI) Working Group (WG) Criteria. Results Thirty-three eligible patients were accrued to dose levels 1 to 8. The maximum-tolerated dose was not reached. The most common adverse effects included transaminitis (33%, all grade 1), abdominal pain (30% grade 1, 0% grade 2, and 3% grade 3), and nausea (39% grade 1 and 9% grade 2). One patient experienced an NCI WG partial remission. Other signs of clinical activity were also observed, with 11 patients (33%) having a sustained ≥ 20% reduction in absolute lymphocyte count (ALC) and 11 (92%) of 12 patients with palpable adenopathy experiencing at least a 50% reduction in the sum of the products of all nodal areas during treatment. Trough plasma EGCG levels after 1 month of treatment ranged from 2.9 to 3,974 ng/mL (median, 40.4 ng/mL). Conclusion Daily oral EGCG in the Polyphenon E preparation was well tolerated by CLL patients in this phase I trial. Declines in ALC and/or lymphadenopathy were observed in the majority of patients. A phase II trial to evaluate efficacy using 2,000 mg twice a day began in November 2007.