Pharmacogenetic and clinical risk factors for bevacizumab-related gastrointestinal hemorrhage in prostate cancer patients treated on CALGB 90401 (Alliance)

The objective of this study was to discover clinical and pharmacogenetic factors associated with bevacizumab-related gastrointestinal hemorrhage in Cancer and Leukemia Group B (Alliance) 90401. Patients with metastatic castration-resistant prostate cancer received docetaxel and prednisone ± bevacizumab. Patients were genotyped using Illumina HumanHap610-Quad and assessed using cause-specific risk for association between single nucleotide polymorphisms (SNPs) and gastrointestinal hemorrhage. In 1008 patients, grade 2 or higher gastrointestinal hemorrhage occurred in 9.5% and 3.8% of bevacizumab (n = 503) and placebo (n = 505) treated patients, respectively. Bevacizumab (P < 0.001) and age (P = 0.002) were associated with gastrointestinal hemorrhage. In 616 genetically estimated Europeans (n = 314 bevacizumab and n = 302 placebo treated patients), grade 2 or higher gastrointestinal hemorrhage occurred in 9.6% and 2.0% of patients, respectively. One SNP (rs1478947; HR 6.26; 95% CI 3.19-12.28; P = 9.40 × 10-8) surpassed Bonferroni-corrected significance. Grade 2 or higher gastrointestinal hemorrhage rate was 33.3% and 6.2% in bevacizumab-treated patients with the AA/AG and GG genotypes, versus 2.9% and 1.9% in the placebo arm, respectively. Prospective validation of these findings and functional analyses are needed to better understand the genetic contribution to treatment-related gastrointestinal hemorrhage.

Abstract 2037: A discovery study to identify clinical and genetic risk factors for bevacizumab (BEV)-related gastrointestinal (GI) hemorrhage (HEM) in metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated on CALGB 90401 (Alliance)

Background: Treatment-related GI HEM is a major health concern with few known predictive risk factors. The objective of this analysis was to discover clinical and genetic factors that modulate GI HEM risk in a large randomized phase III study.

Methods: Chemotherapy-naïve mCRPC pts were randomized 1:1 to receive docetaxel and prednisone ± BEV once every 21 days for up to two years (N = 1008). Cause-specific time-to-event analysis using a Cox regression model was used to investigate the association between grade 2+ GI HEM (designated as at least “probably” related to therapy) and BEV, age, history (hx) of peptic ulcer disease (PUD), hx of HEM, antiplatelet/anticoagulant use, hx of smoking, and hemoglobin. Genetically-defined Caucasian pts who provided consent for the genomic companion study (CALGB 60404) were genotyped using the Illumina HumanHap610-Quad platform (N = 616). Log rank test was used to investigate the association of single nucleotide polymorphisms (SNPs) and GI HEM, and results were adjusted for significant clinical covariates.

Results: The overall incidence of grade 2+ GI HEM was 9.5% (48/503) and 3.8% (19/505) in the BEV and placebo arms, respectively. Of the clinical covariates, only BEV (HR = 5.77; 95% CI 2.20-15.11; P&lt;0.001) and age (HR = 1.06; 95% CI 1.01-1.11; P = 0.01) were significantly associated with GI HEM in the multivariable analysis, while a trend was noted for hx of PUD (P = 0.08). Of 498,081 SNPs tested, one intergenic SNP (rs1478947; HR 6.26; 95% CI 3.00-14.4; P = 9.40 × 10-8) surpassed Bonferroni-corrected significance (1.0 × 10-7) for association with GI HEM (minor allele frequency = 0.06). The incidence of GI HEM in the BEV arm was 33.3% (13/39) and 6.2% (17/275) for pts with the AA/AG and GG genotypes, while the incidence in the placebo arm was 2.9% (1/35) and 1.9% (5/267), respectively.

Conclusion: BEV, age, and one putative intergenic SNP (rs1478947) were associated with cause-specific GI HEM risk in CALGB 90401. The effect of rs1478947 appears to be specific to pts receiving BEV. Although the mechanism by which rs1478947 increases GI HEM risk remains unclear, rs1478947 is in complete LD (r2 = 1) with rs1478948, variations of which may alter the binding motif for transcription factor hepatocyte nuclear factor-4 (HNF4). HNF4 exerts a major regulatory effect on clotting factor VII (fVII) expression and function. Altered binding of HNF4 to fVII promoter may result in reduced fVII function and an increased risk of bleeding. It is unclear how much weight each identified risk factor contributes to the overall incidence of GI HEM, which in absolute terms was not dramatically different between arms. Exploratory studies from large trials of BEV-treated pts are needed to better understand the genetic contribution to and biological basis of GI HEM. Support: U10CA180821

Citation Format: Jai N. Patel, Chen Jiang, Kouros Owzar, Daniel L. Hertz, Flora A. Mulkey, William K. Kelly, Susan Halabi, Yoichi Furukawa, Cameron Lassiter, Susan G. Dorsey, Paula N. Friedman, Eric J. Small, Michael A. Carducci, John F. Mahoney, Michael J. Kelley, Yusuke Nakamura, Michiaki Kubo, Mark J. Ratain, Michael J. Morris, Howard L. McLeod. A discovery study to identify clinical and genetic risk factors for bevacizumab (BEV)-related gastrointestinal (GI) hemorrhage (HEM) in metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated on CALGB 90401 (Alliance). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2037.

Bevacizumab and the risk of arterial and venous thromboembolism in patients with metastatic, castration-resistant prostate cancer treated on Cancer and Leukemia Group B (CALGB) 90401 (Alliance)

BACKGROUND

Bevacizumab is associated with an increased risk of arterial thromboembolism (ATE); however, its effect on venous thromboembolism (VTE) remains controversial. Scant data exist on the factors that increase the risk of ATE/VTE in patients with prostate cancer. The authors investigated the association of bevacizumab treatment and clinical factors with ATE/VTE risk in patients who were treated on Cancer and Leukemia Group B (CALGB) trial 90401.

METHODS

Patients with metastatic, castration-resistant prostate cancer were randomized to receive docetaxel and prednisone with or without bevacizumab once every 21 days. Cycle-to-event Cox regression models were used to investigate the association of bevacizumab with the incidence of grade 3 or greater (≥ 3) ATE and VTE. Age, prior ATE/VTE, baseline antiplatelet/anticoagulant use, and VTE risk score (based on leukocyte count, hemoglobin, platelet count, body mass index, and tumor location) were evaluated in univariate and multivariable analyses.

RESULTS

Of 1008 randomized patients, the odds of experiencing grade ≥ 3 ATE were significantly greater in those who received bevacizumab compared with those who received placebo (odds ratio, 2.79; P = .02), whereas an opposite trend was noted for grade ≥ 3 VTE (odds ratio, 0.60; P = .08). In the multivariable analysis, bevacizumab treatment (hazard ratio [HR], 3.00; P = .01) and age (HR, 1.06; P = .02) were significantly associated with the risk of ATE; whereas age (HR, 1.05; P = .01) and VTE risk score (HR, 1.83; P = .03) were significantly associated with the risk of VTE.

CONCLUSIONS

Bevacizumab was significantly associated with a greater risk of ATE in patients with metastatic, castration-resistant prostate cancer, but it was not significantly associated with the risk of VTE. Understanding clinical factors that increase the risk for experiencing ATE/VTE is essential to mitigate the risks and reduce the burden of these prevalent complications in cancer care.

Abstract 3841: Bevacizumab (BEV) and risk of arterial (ATE) and venous thromboembolism (VTE) in metastatic castration-resistant prostate cancer (mCRPC) patients treated on CALGB 90401(ALLIANCE)

Background BEV is associated with an increased risk of ATE, however, its effect on VTE remains controversial. We investigated the association of BEV treatment and clinical risk factors with the incidence of ATE and VTE in a large randomized phase III study.

Methods mCRPC patients were randomized to receive docetaxel and prednisone with or without BEV once every 21 days. Competing risks cycle-to-event Cox regression models were used to investigate the association of BEV on the incidence of grade 3 or higher (3+) ATE (“cardiac ischemia/infarction” or “CNS ischemia”) and VTE (“thrombosis/thrombus/embolism”). Age, prior ATE/VTE, baseline antiplatelet/anticoagulant and VTE risk score were evaluated in univariable and multivariable analyses.

Results The analysis included 800 patients. The odds of experiencing grade 3+ ATE was significantly greater in BEV treated patients compared to placebo (OR 4.16, P=0.006; 4.02% [16/398] and 1.00% [4/402], respectively). The odds of experiencing grade 3+ VTE was lower in BEV treated patients compared to placebo (OR=0.57, P=0.08; 4.52% [18/398] and 7.71% [31/402], respectively). In the multivariable analysis, BEV treatment (HR=4.28; P=0.009) and prior ATE (HR=2.71; P=0.047) were associated with increased ATE, while age (HR=1.05; P=0.009) and VTE risk score (HR=2.24; P=0.007), but not BEV treatment (HR=0.62; P=0.11), were associated with increased VTE (Table 1).

Conclusion Due to the lack of survival benefit noted in the clinical trial, these results further reinforce the recommendation for not using BEV in this patient population, as it also placed patients at a significantly greater risk for ATE. However, the influence on VTE, if any, was a decreased risk. Understanding the risk factors for ATE and VTE is essential to mitigate risks and reduce the burden of these prevalent complications in cancer care.

Table 1 Risk of ATE and VTE by treatment arm and clinical risk factors

Table 1Risk of ATE and VTE by treatment arm and clinical risk factorsATERisk factorVTECause-specific HRCause-specific HR(95% CI)(95% CI)P-valueP-valueMultivariableUnivariableUnivariableMultivariable4.283.96BEV treatment0.560.62(1.42-12.84)(1.32-11.85)(0.31-1.00)(0.35-1.12)0.0090.0140.0510.111.051.05Agea1.041.05(0.99-1.11)(1.00-1.11)(1.01-1.08)(1.01-1.09)0.120.070.020.0092.713.48Prior thrombosis1.030.97(1.01-7.26)(1.33-9.07)(0.25-4.26)(0.23-4.07)0.0470.010.960.971.631.87Baseline antiplatelet/ anticoagulant 0.940.82(0.62-4.27)(0.72-4.86)(0.53-1.67)(0.46-1.47)0.320.20.850.51N/AN/AVTE risk scoreb2.012.24(1.14-3.54)(1.25-4.01)0.0150.007aAge as a continuous variablebLow, intermediate, or high risk if 0, 1-2, or ≥ 3 risk factors (hemoglobin &lt; 10 g/dL, platelet count ≥ 350,000/µl, leukocyte count &gt; 11,000/µl, body mass index ≥ 35 kg/m2), respectively; low vs. intermediate/high.

Citation Format: Jai N. Patel, Chen Jiang, Daniel L. Hertz, Flora A. Mulkey, Paula N. Friedman, Susan Halabi, Mark J. Ratain, Michael J. Morris, Eric J. Small, Kouros Owzar, William K. Kelly, Howard L. McLeod. Bevacizumab (BEV) and risk of arterial (ATE) and venous thromboembolism (VTE) in metastatic castration-resistant prostate cancer (mCRPC) patients treated on CALGB 90401(ALLIANCE). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3841. doi:10.1158/1538-7445.AM2014-3841

Autologous transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia achieves outcomes similar to allogeneic transplantation: results of CALGB Study 10001 (Alliance)

Allogeneic stem cell transplantation is the standard approach to Philadelphia chromosome positive acute lymphoblastic leukemia. We hypothesized that imatinib plus sequential chemotherapy will result in significant leukemia cell cytoreduction in patients with Philadelphia chromosome positive acute lymphoblastic leukemia, allowing collection of normal hematopoietic stem cells uncontaminated by residual BCR/ABL1(+) lymphoblasts and thus reduce the likelihood of relapse after autologous stem cell transplantation for patients under 60 years of age without sibling donors. We enrolled 58 patients; 19 underwent autologous and 15 underwent allogeneic stem cell transplantation on study. Imatinib plus sequential chemotherapy resulted in reverse-transcriptase polymerase chain reaction-negative stem cells in 9 patients and remained minimally positive in 4 (6 were not evaluable). Overall survival (median 6.0 years vs. not reached) and disease-free survival (median 3.5 vs. 4.1 years) were similar between those who underwent autologous and those who underwent allogeneic stem cell transplantation. We conclude that autologous stem cell transplantation represents a safe and effective alternative for allogeneic stem cell transplantation in Philadelphia chromosome positive acute lymphoblastic leukemia patients without sibling donors (clinicaltrials.gov identifier:00039377).