Plasma-Based Measurements of Tumor Heterogeneity Correlate with Clinical Outcomes in Metastatic Colorectal Cancer.

Sequencing circulating tumor DNA (ctDNA) from liquid biopsies may better assess tumor heterogeneity than limited sampling of tumor tissue. Here, we explore ctDNA-based heterogeneity and its correlation with treatment outcome in STEAM, which assessed efficacy and safety of concurrent and sequential FOLFOXIRI-bevacizumab (BEV) vs. FOLFOX-BEV for first-line treatment of metastatic colorectal cancer. We sequenced 146 pre-induction and 89 post-induction patient plasmas with a 198-kilobase capture-based assay, and applied Mutant-Allele Tumor Heterogeneity (MATH), a traditionally tissue-based calculation of allele frequency distribution, on somatic mutations detected in plasma. Higher levels of MATH, particularly in the post-induction sample, were associated with shorter progression-free survival (PFS). Patients with high MATH vs. low MATH in post-induction plasma had shorter PFS (7.2 vs. 11.7 months; hazard ratio, 3.23; 95% confidence interval, 1.85−5.63; log-rank p < 0.0001). These results suggest ctDNA-based tumor heterogeneity may have potential prognostic value in metastatic cancers.

Assessment of Capecitabine and Bevacizumab With or Without Atezolizumab for the Treatment of Refractory Metastatic Colorectal Cancer: A Randomized Clinical Trial.

Importance: Cotargeting vascular endothelial growth factor and programmed cell death 1 or programmed cell death ligand 1 may produce anticancer activity in refractory metastatic colorectal cancer (mCRC). The clinical benefit of atezolizumab combined with chemotherapy and bevacizumab remains unclear for the treatment of mCRC. Objectives: To assess whether the addition of atezolizumab to capecitabine and bevacizumab therapy improves progression-free survival (PFS) among patients with refractory mCRC and to perform exploratory analyses among patients with microsatellite-stable (MSS) disease and liver metastasis. Design, Setting, and Participants: This double-blind phase 2 randomized clinical trial enrolled 133 patients between September 25, 2017, and June 28, 2018 (median duration of follow-up for PFS, 20.9 months), with data cutoff on May 4, 2020. The study was conducted at multiple centers through the Academic and Community Cancer Research United network. Adult patients with mCRC who experienced disease progression while receiving fluoropyrimidine, oxaliplatin, irinotecan, bevacizumab, and anti-epidermal growth factor receptor antibody therapy (if the patient had a RAS wild-type tumor) were included. Interventions: Patients were randomized (2:1) to receive capecitabine (850 or 1000 mg/m2) twice daily on days 1 to 14 and bevacizumab (7.5 mg/kg) on day 1 plus either atezolizumab (1200 mg; investigational group) or placebo (placebo group) on day 1 of each 21-day cycle. Main Outcomes and Measures: The primary end point was PFS; 110 events were required to detect a hazard ratio (HR) of 0.65 with 80% power (1-sided α = .10). Secondary end points were objective response rate, overall survival (OS), and toxic effects. Results: Of 133 randomized patients, 128 individuals (median age, 58.0 years [IQR, 51.0-65.0 years]; 77 men [60.2%]) were assessed for efficacy (82 in the investigational group and 46 in the placebo group). Overall, 15 patients (11.7%) self-identified as African American or Black, 8 (6.3%) as Asian, 1 (0.8%) as Pacific Islander, 101 (78.9%) as White, 1 (0.8%) as multiple races (Asian, Native Hawaiian/Pacific Islander, and White), and 2 (1.6%) as unknown race or unsure of race. Microsatellite-stable disease was present in 110 patients (69 in the investigational group and 41 in the placebo group). Median PFS was 4.4 months (95% CI, 4.1-6.4 months) in the investigational group and 3.6 months (95% CI, 2.2-6.2 months) in the placebo group (1-sided log-rank P = .07, a statistically significant result; HR, 0.75; 95% CI, 0.52-1.09). Among patients with MSS and proficient mismatch repair, the HR for PFS was 0.66 (95% CI, 0.44-0.99). The most common grade 3 or higher treatment-related adverse events in the investigational vs placebo groups were hypertension (6 patients [7.0%] vs 2 patients [4.3%]), diarrhea (6 patients [7.0%] vs 2 patients [4.3%]), and hand-foot syndrome (6 patients [7.0%] vs 2 patients [4.3%]). One treatment-related death occurred in the investigational group. In the investigational group, the response rate was higher among patients without liver metastasis (3 of 13 individuals [23.1%]) vs with liver metastasis (4 of 69 individuals [5.8%]). The benefit of atezolizumab for PFS and OS was greater among patients without vs with liver metastasis (primary analysis of PFS: HR, 0.63 [95% CI, 0.27-1.47] vs 0.77 [95% CI, 0.51-1.17]; OS: HR, 0.33 [95% CI, 0.11-1.02] vs 1.14 [95% CI, 0.72-1.81]). Conclusions and Relevance: In this randomized clinical trial, the addition of atezolizumab to capecitabine and bevacizumab therapy provided limited (ie, not clinically meaningful) clinical benefit. Patients with MSS and proficient mismatch repair tumors and those without liver metastasis benefited more from dual inhibition of the vascular endothelial growth factor and programmed cell death 1 or programmed cell death ligand 1 pathways. Trial Registration: ClinicalTrials.gov Identifier: NCT02873195.

Predictive Biomarkers of Overall Survival in Patients with Metastatic Renal Cell Carcinoma Treated with IFNα ± Bevacizumab: Results from CALGB 90206 (Alliance).

PURPOSE: CALGB 90206 was a phase III trial of 732 patients with metastatic renal cell carcinoma (mRCC) comparing bevacizumab plus IFNα (BEV + IFN) with IFNα alone (IFN). No difference in overall survival (OS) was observed. Baseline samples were analyzed to identify predictive biomarkers for survival benefit. PATIENTS AND METHODS: A total of 32 biomarkers were assessed in 498 consenting patients randomly assigned into training (n = 279) and testing (n = 219) sets. The proportional hazards model was used to test for treatment arm and biomarker interactions of OS. The estimated coefficients from the training set were used to compute a risk score for each patient and to classify patients by risk in the testing set. The resulting model was assessed for predictive accuracy using the time-dependent area under the ROC curve (tAUROC). RESULTS: A statistically significant three-way interaction between IL6, hepatocyte growth factor (HGF), and bevacizumab treatment was observed in the training set and confirmed in the testing set (P < 0.0001). The model based on IL6, HGF, and bevacizumab treatment was predictive of OS (P < 0.001), with the high- and low-risk groups having a median OS of 10.2 [95% confidence interval (CI), 8.0-13.8] and 34.3 (95% CI, 28.5-40.5) months, respectively. The average tAUROC for the final model of OS based on 100 randomly split testing sets was 0.78 (first, third quartiles = 0.77, 0.79). CONCLUSIONS: IL6 and HGF are potential predictive biomarkers of OS benefit from BEV + IFN in patients with mRCC. The model based on key biological and clinical factors demonstrated predictive efficacy for OS. These markers warrant further validation in future anti-VEGF and immunotherapy in mRCC trials. See related commentaries by Mishkin and Kohn, p. 2722 and George and Bertagnolli, p. 2725.

Plasma Protein Biomarkers in Advanced or Metastatic Colorectal Cancer Patients Receiving Chemotherapy With Bevacizumab or Cetuximab: Results from CALGB 80405 (Alliance).

PURPOSE: CALGB 80405 compared the combination of first-line chemotherapy with cetuximab or bevacizumab in the treatment of advanced or metastatic colorectal cancer (mCRC). Although similar clinical outcomes were observed in the cetuximab-chemotherapy group and the bevacizumab-chemotherapy group, biomarkers could identify patients deriving more benefit from either biologic agent. PATIENTS AND METHODS: In this exploratory analysis, the Angiome, a panel of 24 soluble protein biomarkers were measured in baseline plasma samples in CALGB 80405. Prognostic biomarkers were determined using univariate Cox proportional hazards models. Predictive biomarkers were identified using multivariable Cox regression models including interaction between biomarker level and treatment. RESULTS: In the total population, high plasma levels of Ang-2, CD73, HGF, ICAM-1, IL6, OPN, TIMP-1, TSP-2, VCAM-1, and VEGF-R3 were identified as prognostic of worse progression-free survival (PFS) and overall survival (OS). PlGF was identified as predictive of lack of PFS benefit from bevacizumab [bevacizumab HR, 1.51; 95% confidence interval (CI), 1.10-2.06; cetuximab HR, 0.94; 95% CI, 0.71-1.25; Pinteraction = 0.0298] in the combined FOLFIRI/FOLFOX regimens. High levels of VEGF-D were predictive of lack of PFS benefit from bevacizumab in patients receiving FOLFOX regimen only (FOLFOX/bevacizumab HR, 1.70; 95% CI, 1.19-2.42; FOLFOX/cetuximab HR, 0.92; 95% CI, 0.68-1.24; Pinteraction = 0.0097). CONCLUSIONS: In this exploratory, hypothesis-generating analysis, the Angiome identified multiple prognostic biomarkers and two potential predictive biomarkers for patients with mCRC enrolled in CALGB 80405. PlGF and VEGF-D predicted lack of benefit from bevacizumab in a chemo-dependent manner. See related commentaries by Mishkin and Kohn, p. 2722 and George and Bertagnolli, p. 2725.

Cabozantinib and Panitumumab for RAS Wild-Type Metastatic Colorectal Cancer.

LESSONS LEARNED: Antitumor activity was observed in the study population. Dose modifications of cabozantinib improve long-term tolerability. Biomarkers are needed to identify patient populations most likely to benefit. Further study of cabozantinib with or without panitumumab in patients with metastatic colorectal cancer is warranted. BACKGROUND: The epidermal growth factor receptor (EGFR) antibody panitumumab is active in patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC), but nearly all patients experience resistance. MET amplification is a driver of panitumumab resistance. Cabozantinib is an inhibitor of multiple kinases, including vascular endothelial growth factor receptor 2 (VEGFR2) and c-MET, and may delay or reverse anti-EGFR resistance. METHODS: In this phase Ib clinical trial, we established the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of cabozantinib and panitumumab. We then treated an expansion cohort to further describe the tolerability and clinical activity of the RP2D. Eligibility included patients with KRAS WT mCRC (later amended to include only RAS WT mCRC) who had received prior treatment with a fluoropyrimidine, oxaliplatin, irinotecan, and bevacizumab. RESULTS: Twenty-five patients were enrolled and treated. The MTD/RP2D was cabozantinib 60 mg p.o. daily and panitumumab 6 mg/kg I.V. every 2 weeks. The objective response rate (ORR) was 16%. Median progression free survival (PFS) was 3.7 months (90% confidence interval [CI], 2.3-7.1). Median overall survival (OS) was 12.1 months (90% CI, 7.5-14.3). Five patients (20%) discontinued treatment due to toxicity, and 18 patients (72%) required a dose reduction of cabozantinib. CONCLUSION: The combination of cabozantinib and panitumumab has activity. Dose reductions of cabozantinib improve tolerability.

Bevacizumab (Avastin®) in cancer treatment: A review of 15 years of clinical experience and future outlook.

When the VEGF-A-targeting monoclonal antibody bevacizumab (Avastin®) entered clinical practice more than 15 years ago, it was one of the first targeted therapies and the first approved angiogenesis inhibitor. Marking the beginning for a new line of anti-cancer treatments, bevacizumab remains the most extensively characterized anti-angiogenetic treatment. Initially approved for treatment of metastatic colorectal cancer in combination with chemotherapy, its indications now include metastatic breast cancer, non-small-cell lung cancer, glioblastoma, renal cell carcinoma, ovarian cancer and cervical cancer. This review provides an overview of the clinical experience and lessons learned since bevacizumab's initial approval, and highlights how this knowledge has led to the investigation of novel combination therapies. In the past 15 years, our understanding of VEGF's role in the tumor microenvironment has evolved. We now know that VEGF not only plays a major role in controlling blood vessel formation, but also modulates tumor-induced immunosuppression. These immunomodulatory properties of bevacizumab have opened up new perspectives for combination therapy approaches, which are being investigated in clinical trials. Specifically, the combination of bevacizumab with cancer immunotherapy has recently been approved in non-small-cell lung cancer and clinical benefit was also demonstrated for treatment of hepatocellular carcinoma. However, despite intense investigation, reliable and validated biomarkers that would enable a more personalized use of bevacizumab remain elusive. Overall, bevacizumab is expected to remain a key agent in cancer therapy, both due to its established efficacy in approved indications and its promise as a partner in novel targeted combination treatments.

Disease Monitoring Using Post-induction Circulating Tumor DNA Analysis Following First-Line Therapy in Patients with Metastatic Colorectal Cancer.

PURPOSE: We assessed plasma circulating tumor DNA (ctDNA) level as a prognostic marker for progression-free survival (PFS) following first-line metastatic colorectal cancer (mCRC) therapy. EXPERIMENTAL DESIGN: The Sequencing Triplet With Avastin and Maintenance (STEAM) was a randomized, phase II trial investigating efficacy of bevacizumab (BEV) plus 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX) and 5-fluorouracil/leucovorin/irinotecan (FOLFIRI), administered concurrently or sequentially, versus FOLFOX-BEV in first-line mCRC. Evaluation of biomarkers associated with treatment outcomes was an exploratory endpoint. Patients in the biomarker-evaluable population (BEP) had 1 tissue sample, 1 pre-induction plasma sample, and 1 post-induction plasma sample collected ≤60 days of induction from last drug date. RESULTS: Among the 280 patients enrolled in STEAM, 183 had sequenced and evaluable tumor tissue, 118 had matched pre-induction plasma, and 54 (BEP) had ctDNA-evaluable sequencing data for pre- and post-induction plasma. The most common somatic variants in tumor tissue and pre-induction plasma were TP53, APC, and KRAS. Patients with lower-than-median versus higher-than-median post-induction mean allele fraction (mAF) levels had longer median PFS (17.7 vs. 7.5 months, HR, 0.33; 95% confidence interval, 0.17-0.63). Higher levels of post-induction mAF and post-induction mean mutant molecules per milliliter (mMMPM), and changes in ctDNA (stratified by a 10-fold or 100-fold reduction in mAF between pre- and post-induction plasma), were associated with shorter PFS. Post-induction mAF and mMMPM generally correlated with each other (ρ = 0.987, P < 0.0001). CONCLUSIONS: ctDNA quantification in post-induction plasma may serve as a prognostic biomarker for mCRC post-treatment outcomes.

Predictive Blood-Based Biomarkers in Patients with Epithelial Ovarian Cancer Treated with Carboplatin and Paclitaxel with or without Bevacizumab: Results from GOG-0218.

PURPOSE: GOG-0218, a double-blind placebo-controlled phase III trial, compared carboplatin and paclitaxel with placebo, bevacizumab followed by placebo, or bevacizumab followed by bevacizumab in advanced epithelial ovarian cancer (EOC). Results demonstrated significantly improved progression-free survival (PFS), but no overall survival (OS) benefit with bevacizumab. Blood samples were collected for biomarker analyses. EXPERIMENTAL DESIGN: Plasma samples were analyzed via multiplex ELISA technology for seven prespecified biomarkers [IL6, Ang-2, osteopontin (OPN), stromal cell-derived factor-1 (SDF-1), VEGF-D, IL6 receptor (IL6R), and GP130]. The predictive value of each biomarker with respect to PFS and OS was assessed using a protein marker by treatment interaction term within the framework of a Cox proportional hazards model. Prognostic markers were identified using Cox models adjusted for baseline covariates. RESULTS: Baseline samples were available from 751 patients. According to our prespecified analysis plan, IL6 was predictive of a therapeutic advantage with bevacizumab for PFS (P = 0.007) and OS (P = 0.003). IL6 and OPN were found to be negative prognostic markers for both PFS and OS (P < 0.001). Patients with high median IL6 levels (dichotomized at the median) treated with bevacizumab had longer PFS (14.2 vs. 8.7 months) and OS (39.6 vs. 33.1 months) compared with placebo. CONCLUSIONS: The inflammatory cytokine IL6 may be predictive of therapeutic benefit from bevacizumab when combined with carboplatin and paclitaxel. Aligning with results observed in patients with renal cancer treated with antiangiogenic therapies, it appears plasma IL6 may also define those patients with EOC more or less likely to benefit from the addition of bevacizumab to standard chemotherapy.

A phase Ib study of capecitabine and ziv-aflibercept followed by a phase II single-arm expansion cohort in chemotherapy refractory metastatic colorectal cancer.

BACKGROUND: Patients with chemotherapy refractory metastatic colorectal cancer (CRC) have a poor prognosis and limited therapeutic options. In this phase Ib/II clinical trial, we established the maximum tolerated dose (MTD) and recommended phase II dose (RPTD) for the combination of capecitabine and ziv-aflibercept, and then we evaluated the efficacy of the combination in patients with chemotherapy refractory metastatic CRC. METHODS: All patients were required to have a Karnofsky Performance Status > 70% and adequate organ function. The phase Ib dose escalation cohort included patients with advanced solid tumors who had progressed on all standard therapies. Using a standard 3 + 3 design, we identified the MTD and RPTD for the combination. Fifty patients with metastatic CRC who had progressed on or were intolerant of a fluoropyrimidine, oxaliplatin, irinotecan, and bevacizumab were then enrolled in a single-arm phase II expansion cohort, and were treated at the RPTD. Prior EGFR antibody therapy was required for subjects with RAS wildtype tumors. The primary endpoint for the expansion cohort was progression-free survival (PFS) at two months. Secondary endpoints included objective response rate (ORR) and overall survival (OS). RESULTS: A total of 63 patients were enrolled and evaluable for toxicity (13 dose escalation; 50 expansion). The MTD and RPTD were: capecitabine 850 mg/m2, P.O. bid, days 1-14, and ziv-aflibercept 6 mg/kg I.V., day 1, of each 21-day cycle. In the expansion cohort, 72% of patients were progression-free at two months (95% confidence interval [CI], 60-84%). Median PFS and OS were 3.9 months (95% CI, 2.3-4.5) and 7.1 months (95% CI: 5.8-10.0), respectively. Among all patients evaluable for toxicity, the most common treatment related adverse events (all grade [%]; grade ≥ 3 [%]) included palmar-plantar erythrodysesthesia (41%; 6%), hypertension (33%; 22%), and mucositis (19%; 5%). RNA was isolated from archived tumor specimens and gene expression analyses revealed no association between angiogenic biomarkers and clinical outcomes. CONCLUSION: The combination of capecitabine and ziv-aflibercept at the RPTD demonstrated acceptable safety and tolerability. PFS at 2 months in patients with chemotherapy refractory metastatic CRC was significantly greater than that in historical controls, indicating that this combination warrants further study. TRIAL REGISTRATION: This clinical trial was registered in the www.clinicaltrials.gov system as NCT01661972 on July 31, 2012.

A phase Ib study of the combination regorafenib with PF-03446962 in patients with refractory metastatic colorectal cancer (REGAL-1 trial).

PURPOSE: This study aimed to evaluate the maximum tolerated dose (MTD) and recommended phase II dose (RPTD), as well as the safety and tolerability of PF-03446962, a monoclonal antibody targeting activin receptor like kinase 1 (ALK-1), in combination with regorafenib in patients with refractory metastatic colorectal cancer. METHODS: The first stage of this study was a standard "3 + 3" open-label dose-escalation scheme. Cohorts of 3-6 subjects were started with 120 mg of regorafenib given PO daily for 3 weeks of a 4 week cycle, plus 4.5 mg/kg of PF-03446962 given IV every 2 weeks. Doses of both drugs were adjusted according to dose-limiting toxicities (DLT). Plasma was collected for multiplexed ELISA analysis of factors related to tumor growth and angiogenesis. RESULTS: Seventeen subjects were enrolled, of whom 11 were deemed evaluable. Seven subjects were enrolled at dose level 1, and four were enrolled at level - 1. Overall, three DLTs were observed during the dose-escalation phase: two in level 1 and one in level - 1. A planned dose-expansion cohort was not started due to early termination of the clinical trial. Common adverse events were infusion-related reaction, fatigue, palmar-plantar erythrodysesthesia syndrome, abdominal pain, dehydration, nausea, back pain, anorexia, and diarrhea. One subject achieved stable disease for 5.5 months, but discontinued treatment due to adverse events. CONCLUSIONS: The regimen of regorafenib and PF-03446962 was associated with unacceptable toxicity and did not demonstrate notable clinical activity in patients with refractory metastatic colorectal cancer.

The effects of lapatinib on cardiac repolarization: results from a placebo controlled, single sequence, crossover study in patients with advanced solid tumors.

PURPOSE: To evaluate the effect of lapatinib on the QTc interval and ECG parameters in patients with advanced solid tumors. METHODS: This was a multicenter, placebo-controlled study in subjects with advanced solid tumors. Subjects were administered two doses of matching placebo on day 1, 12 h apart and one dose in the morning on day 2. Two doses of lapatinib 2000 mg were administered orally on day 3, 12 h apart and one dose in the morning on day 4. Twelve-lead digital ECGs were extracted from continuous Holter recordings at pre-specified time points over the 24-h period on days 2 and 4. Venous blood samples for lapatinib concentrations were obtained immediately following the ECGs. RESULTS: A maximum mean baseline-adjusted, placebo time-matched increase in QTcF, (ddQTcF) in the evaluable, (EV) population (n = 37) of 8.8 ms (90% CI 4.1, 13.4) occurred approximately 10 h after the third lapatinib dose. These results were consistent with those in the pharmacodynamic, PD population, (n = 52) (ddQTcF = 7.9 ms; 90% CI 4.1, 11.7). No subject experienced QTcF increases from baseline of > 60 ms on lapatinib or placebo. The geometric mean lapatinib Cmax of 3902 ng/mL was observed at 3.6 h post-dose. CONCLUSIONS: These data show a relevant, treatment-related increase in QTcF after treatment with three doses of lapatinib 2000 mg. This study confirms the need for caution in patients with solid tumors treated with lapatinib, and who are concomitantly receiving drugs that are strong CYP3A inhibitors and/or prolong the QTc.

An initial genetic analysis of gemcitabine-induced high-grade neutropenia in pancreatic cancer patients in CALGB 80303 (Alliance).

OBJECTIVES: One of the standard of care regimens for advanced pancreatic cancer is gemcitabine-based chemotherapy. The efficacy of gemcitabine is limited by dose-limiting hematologic toxicities especially neutropenia. Uncovering the variability of these toxicities attributed to germline DNA variation is of great importance. PATIENTS AND METHODS: CALGB 80303 was a randomized study in advanced pancreatic cancer patients treated with gemcitabine with or without bevacizumab. The study protocol included genotyping of genes of gemcitabine disposition (CDA, DCTD, SLC29A1, SLC28A1, and SLC29A2), as well as a genome-wide analysis. The clinical phenotype was time to early high-grade neutropenia event accounting for progression or death or other treatment-terminating adverse events as competing for informative events. The inference was carried out on the basis of the association between genotype and cause-specific hazard of a neutropenic event. RESULTS: The primary analyses were carried out on the basis of 294 genetically estimated European pancreatic cancer patients. For CDA rs2072671 (A>C), AC and CC patients had a lower risk of neutropenia than AA patients (P=0.01, hazard ratio: 0.61, 95% confidence interval: 0.41-0.89). For SLC28A1 rs3825876 (G>A), AA patients have a higher risk of neutropenia than GA and GG patients (P=0.02, hazard ratio: 1.51, 95% confidence interval: 1.06-2.16). CDA rs2072671 was associated with increased mRNA expression in whole blood in three studies (P=2.7e-14, 6.61e-62, and 9.70e-65). In the genome-wide analysis, variants in TGFB2 were among the top hits (lowest P=1.62e-06) but had no effect in luciferase assays. CONCLUSION: This is the first genetic analysis of gemcitabine-induced neutropenia using a competing risk model in a prospective randomized clinical study has proposed a potentially novel mechanism of the protective effect of the CDA rs2072671 variant. Further confirmation is needed.

Phase II Randomized Trial of Sequential or Concurrent FOLFOXIRI-Bevacizumab Versus FOLFOX-Bevacizumab for Metastatic Colorectal Cancer (STEAM).

BACKGROUND: First-line treatment for metastatic colorectal cancer (mCRC) typically entails a biologic such as bevacizumab (BEV) with 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX) or 5-fluorouracil/leucovorin/irinotecan (FOLFIRI). STEAM (NCT01765582) assessed the efficacy of BEV plus FOLFOX/FOLFIRI (FOLFOXIRI), administered concurrently (cFOLFOXIRI-BEV) or sequentially (sFOLFOXIRI-BEV, FOLFOX-BEV alternating with FOLFIRI-BEV), versus FOLFOX-BEV for mCRC. PATIENTS AND METHODS: Patients with previously untreated mCRC (n = 280) were randomized 1:1:1 to cFOLFOXIRI-BEV, sFOLFOXIRI-BEV, or FOLFOX-BEV and treated with 4-6-month induction followed by maintenance. Coprimary objectives were overall response rate (ORR; first-line cFOLFOXIRI-BEV vs. FOLFOX-BEV) and progression-free survival (PFS; pooled first-line cFOLFOXIRI-BEV and sFOLFOXIRI-BEV vs. FOLFOX-BEV). Secondary/exploratory objectives included overall survival (OS), liver resection rates, biomarker analyses, and safety. RESULTS: ORR was 72.0%, 72.8%, and 62.1% and median PFS was 11.9, 11.4, and 9.5 months with cFOLFOXIRI-BEV, sFOLFOXIRI-BEV, and FOLFOX-BEV, respectively. OS was similar between arms. ORR between cFOLFOXIRI-BEV and FOLFOX-BEV did not significantly differ (p = .132); thus, the primary ORR endpoint was not met. cFOLFOXIRI-BEV and sFOLFOXIRI-BEV numerically improved ORR and PFS, regardless of RAS status. Median PFS was higher with pooled concurrent and sequential FOLFOXIRI-BEV versus FOLFOX-BEV (11.7 vs. 9.5 months; hazard ratio, 0.7; 90% confidence interval, 0.5-0.9; p < .01). Liver resection rates were 17.2% (cFOLFOXIRI-BEV), 9.8% (sFOLFOXIRI-BEV), and 8.4% (FOLFOX-BEV). Grade ≥ 3 treatment-emergent adverse events (TEAEs) were observed in 91.2% (cFOLFOXIRI-BEV), 86.7% (sFOLFOXIRI-BEV), and 85.6% (FOLFOX-BEV) of patients, with no increase in serious chemotherapy-associated TEAEs. CONCLUSION: cFOLFOXIRI-BEV and sFOLFOXIRI-BEV were well tolerated with numerically improved ORR, PFS, and liver resection rates versus FOLFOX-BEV, supporting triplet chemotherapy plus BEV as a first-line treatment option for mCRC. IMPLICATIONS FOR PRACTICE: The combination of first-line FOLFIRI with FOLFOX and bevacizumab (concurrent FOLFOXIRI-BEV) improves clinical outcomes in patients with metastatic colorectal cancer (mCRC) relative to FOLFIRI-BEV or FOLFOX-BEV, but it is thought to be associated with increased toxicity. Alternating treatment of FOLFOX and FOLFIRI (sequential FOLFOXIRI-BEV) could improve tolerability. In the phase II STEAM trial, which is the largest study of FOLFOXIRI-BEV in patients in the U.S., it was found that both concurrent and sequential FOLFOXIRI-BEV are active and well tolerated in patients with previously untreated mCRC, supporting the use of these regimens as potential first-line treatment options for this population.

Impact of primary tumour location on efficacy of bevacizumab plus chemotherapy in metastatic colorectal cancer.

BACKGROUND: Two first-line (1L) bevacizumab trials showed the prognostic value of primary tumour location in metastatic colorectal cancer (mCRC). In this retrospective subgroup analysis, further analysis of the predictive effect of bevacizumab is presented. METHODS: Patients with sidedness information from two randomised phase III studies of bevacizumab + chemotherapy (CT) vs CT as 1L mCRC treatment were analysed retrospectively. RESULTS: Sidedness was determined in 1590 (27% right and 73% left) of 2214 patients. Progression-free survival was improved with bevacizumab + CT vs CT in right-sided (HR = 0.75; 95% CI 0.61, 0.93; p = 0.008) and left-sided (HR = 0.76; 95% CI 0.67, 0.86; p < 0.001) mCRC (pooled analysis). Similarly, overall survival was numerically improved with bevacizumab + CT vs CT in right-sided mCRC (HR = 0.82; 95% CI 0.65, 1.03; p = 0.085), and significantly improved in left-sided mCRC (HR = 0.85; 95% CI 0.74, 0.98; p = 0.028). CONCLUSIONS: This analysis indicates that the effect of bevacizumab is independent of tumour location in mCRC.

Genetic variation determines VEGF-A plasma levels in cancer patients.

Angiogenesis is essential in tumor biology and is regulated by vascular endothelial growth factor (VEGF) ligands and receptors. Here we aimed to discover genetic variants associated with levels of circulating angiogenic proteins in cancer patients. Plasma was collected at baseline in 216 pancreatic and 114 colorectal cancer patients. Thirty-one angiogenic proteins were measured by ELISA. 484,523 Single Nucleotide Polymorphisms (SNP) were tested for association with plasma levels for each protein in pancreatic cancer patients. Three top-ranked hits were then genotyped in colorectal cancer patients, where associations with the same proteins were measured. The results demonstrated rs2284284 and MCP1 (P-value = 6.7e-08), rs7504372 and VEGF-C (P-value = 9.8e-09), and rs7767396 and VEGF-A (P-value = 5.8e-09) were SNP-protein pairs identified in pancreatic cancer patients. In colorectal cancer patients, only rs7767396 (A > G) and VEGF-A was validated (P-value = 5.18e-05). The AA genotype of rs7767396 exhibited 2.04-2.3 and 2.7-3.4-fold higher VEGF-A levels than those with AG and GG genotypes. The G allele of rs7767396 reduces binding of the NF-AT1 transcription factor. In conclusion, a common genetic variant predicts the plasma levels of VEGF-A in cancer patients through altered binding of NF-AT1.

Modulation of Circulating Protein Biomarkers in Cancer Patients Receiving Bevacizumab and the Anti-Endoglin Antibody, TRC105.

TRC105 is an anti-endoglin antibody currently being tested in combination with VEGF inhibitors. In the phase Ib trial, 38 patients were treated with both TRC105 and bevacizumab (BEV), and improved clinical outcomes were observed, despite the fact that 30 patients (79%) were refractory to prior anti-VEGF therapy. Plasma samples were tested for angiogenic and inflammatory biomarkers at baseline and on-treatment. To provide broader context of this combination biomarker study, direct cross-study comparisons were made to biomarker studies previously conducted in patients treated with either BEV or TRC105 monotherapy. Upon treatment with BEV and TRC105, pharmacodynamic changes in response to both BEV (PlGF increase) and TRC105 (soluble endoglin increase) were noted. In addition, distinct patterns of change were identified (similar, opposing, neutralizing). Similar patterns were observed when the combination elicited similar effects to those observed with monotherapy treatment (i.e., decreases of Ang-2, increases of IL6 and VCAM-1). Opposing patterns were observed when the combination led to opposing effects compared with monotherapy treatment (i.e., TGFß1, PDGF-AA and PDGF-BB, PAI-1). Lastly, neutralizing patterns were observed when one drug led to increase, whereas the other drug led to decrease, and the combination elicited no overall effect on the marker (i.e., VEGF-A, VEGF-D, and IGFBP-3). Patients achieving partial responses or stable disease from the combination exhibited significantly lower expression of E-Cadherin, HGF, ICAM-1, and TSP-2 at baseline. Taken together, the novel biomarker modulations identified may deepen our understanding of the underlying biology in patients treated with BEV and TRC105 compared with either drug alone. Mol Cancer Ther; 17(10); 2248-56. ©2018 AACR.

A Phase I Trial of the IGF-1R Antibody Ganitumab (AMG 479) in Combination with Everolimus (RAD001) and Panitumumab in Patients with Advanced Cancer.

PURPOSE: This study evaluated the maximum tolerated dose or recommended phase II dose (RPTD) and safety and tolerability of the ganitumab and everolimus doublet regimen followed by the ganitumab, everolimus, and panitumumab triplet regimen. MATERIALS AND METHODS: This was a standard 3 + 3 dose escalation trial. Doublet therapy consisted of ganitumab at 12 mg/kg every 2 weeks; doses of everolimus were adjusted according to dose-limiting toxicities (DLTs). Panitumumab at 4.8 mg/kg every 2 weeks was added to the RPTD of ganitumab and everolimus. DLTs were assessed in cycle 1; toxicity evaluation was closely monitored throughout treatment. Treatment continued until disease progression or undesirable toxicity. Pretreatment and on-treatment skin biopsies were collected to assess insulin-like growth factor 1 receptor and mammalian target of rapamycin (mTOR) target modulation. RESULTS: Forty-three subjects were enrolled. In the doublet regimen, two DLTs were observed in cohort 1, no DLTs in cohort -1, and one in cohort -1B. The triplet combination was discontinued because of unacceptable toxicity. Common adverse events were thrombocytopenia/neutropenia, skin rash, mucositis, fatigue, and hyperglycemia. In the doublet regimen, two patients with refractory non-small cell lung cancer (NSCLC) achieved prolonged complete responses ranging from 18 to >60 months; one treatment-naïve patient with chondrosarcoma achieved prolonged stable disease >24 months. In dermal granulation tissue, the insulin-like growth factor receptor and mTOR pathways were potently and specifically inhibited by ganitumab and everolimus, respectively. CONCLUSION: The triplet regimen of ganitumab, everolimus, and panitumumab was associated with unacceptable toxicity. However, the doublet of ganitumab at 12 mg/kg every 2 weeks and everolimus five times weekly had an acceptable safety profile and demonstrated notable clinical activity in patients with refractory NSCLC and sarcoma. IMPLICATIONS FOR PRACTICE: This trial evaluated the maximum tolerated dose or recommended phase II dose and safety and tolerability of the ganitumab and everolimus doublet regimen followed by the ganitumab, everolimus, and panitumumab triplet regimen. Although the triplet regimen of ganitumab, everolimus, and panitumumab was associated with unacceptable toxicity, the doublet of ganitumab at 12 mg/kg every 2 weeks and everolimus at five times weekly had an acceptable safety profile and demonstrated notable clinical activity in patients with refractory non-small cell lung cancer and sarcoma.

A Randomized, Double-Blind, Placebo-Controlled Phase II Study of the Efficacy and Safety of Monotherapy Ontuxizumab (MORAb-004) Plus Best Supportive Care in Patients with Chemorefractory Metastatic Colorectal Cancer.

Purpose: The purpose of this study was to evaluate the safety and efficacy of ontuxizumab (MORAb-004), a monoclonal antibody that interferes with endosialin (tumor endothelial marker-1) function, in patients with chemorefractory metastatic colorectal cancer and to identify a responsive patient population based on biomarkers.Experimental Design: This was a randomized, double-blind, placebo-controlled, phase II study. Patients were randomly assigned in a 2:1 ratio to receive weekly intravenous ontuxizumab (8 mg/kg) or placebo plus best supportive care until progression or unacceptable toxicity. Tissue and blood biomarkers were evaluated for their ability to identify a patient population that was responsive to ontuxizumab.Results: A total of 126 patients were enrolled. No significant difference between the ontuxizumab and placebo groups was evident for the primary endpoint of progression-free survival (PFS), with a median PFS of 8.1 weeks in each group (HR, 1.13; 95% confidence interval, 0.76-1.67; P = 0.53). There were no significant differences between groups for overall survival (OS) or overall response rate (ORR). The most common treatment-emergent adverse events (TEAEs) in the ontuxizumab group (vs. the placebo group, respectively) were fatigue (53.7% vs. 47.5%), nausea (39.0% vs. 35.0%), decreased appetite (34.1% vs. 27.5%), and constipation (28.0% vs. 32.5%). The most common grade 3/4 TEAE in the ontuxizumab group versus placebo was back pain (11.0% vs. 0%). No single biomarker clearly identified patients responsive to ontuxizumab.Conclusions: No benefit with ontuxizumab monotherapy compared with placebo for clinical response parameters of PFS, OS, or ORR was demonstrated. Ontuxizumab was well tolerated. Clin Cancer Res; 24(2); 316-25. ©2017 AACR.

Pilot Evaluation of Angiogenesis Signaling Factor Response after Transcatheter Arterial Embolization for Hepatocellular Carcinoma.

Purpose To identify changes in a broad panel of circulating angiogenesis factors after bland transcatheter arterial embolization (TAE), a purely ischemic treatment for hepatocellular carcinoma (HCC). Materials and Methods This prospective HIPAA-compliant study was approved by the institutional review board. Informed written consent was obtained from all participants prior to entry into the study. Twenty-five patients (21 men; mean age, 61 years; range, 30-81 years) with Liver Imaging Reporting and Data System category 5 or biopsy-proven HCC and who were undergoing TAE were enrolled from October 15, 2014, through December 2, 2015. Nineteen plasma angiogenesis factors (angiopoietin 2; hepatocyte growth factor; platelet-derived growth factor AA and BB; placental growth factor; vascular endothelial growth factor A and D; vascular endothelial growth factor receptor 1, 2, and 3; osteopontin; transforming growth factor ß1 and ß2; thrombospondin 2; intercellular adhesion molecule 1; interleukin 6 [IL-6]; stromal cell-derived factor 1; tissue inhibitor of metalloproteinases 1; and vascular cell adhesion molecule 1 [VCAM-1]) were measured by using enzyme-linked immunosorbent assays at 1 day, 2 weeks, and 5 weeks after TAE and were compared with baseline levels by using paired Wilcoxon tests. Tumor response was assessed according to modified Response Evaluation Criteria in Solid Tumors (mRECIST). Angiogenesis factor levels were compared between responders and nonresponders by mRECIST criteria by using unpaired Wilcoxon tests. Results All procedures were technically successful with no complications. Fourteen angiogenesis factors showed statistically significant changes following TAE, but most changes were transient. IL-6 was upregulated only 1 day after the procedure, but showed the largest increases of any factor. Osteopontin and VCAM-1 demonstrated sustained upregulation at all time points following TAE. At 3-month follow-up imaging, 11 patients had responses to TAE (complete response, n = 6; partial response, n = 5) and 11 patients were nonresponders (stable disease, n = 9; progressive disease, n = 2). In nonresponders, the percent change in IL-6 on the day after TAE (P = .033) and the mean percent change in osteopontin after TAE (P = .024) were significantly greater compared with those of responders. Conclusion Multiple angiogenesis factors demonstrated significant upregulation after TAE. VCAM-1 and osteopontin demonstrated sustained upregulation, whereas the rest were transient. IL-6 and osteopontin correlated significantly with radiologic response after TAE. © RSNA, 2017.

Phase I study of pazopanib plus TH-302 in advanced solid tumors.

PURPOSE: To define the maximum tolerated dose (MTD), recommended phase II dose (RPTD), and assess safety and tolerability for the combination of pazopanib plus TH-302, an investigational hypoxia-activated prodrug (HAP), in adult patients with advanced solid tumors. METHODS: This was an open-label, non-randomized, single-center, phase I trial consisting 2 stages. Stage 1 was a standard "3 + 3" dose escalation design to determine safety and the RPTD for TH-302 plus pazopanib combination. Stage 2 was an expanded cohort to better describe the tolerability and toxicity profile at the MTD. Pazopanib was orally dosed at 800 mg daily on days 1-28 for all cohorts. TH-302 was administered intravenously on days 1, 8 and 15 of a 28-day cycle at doses of 340 mg/m2 (cohort 1) or 480 mg/m2 (cohort 2). Dose limiting toxicity (DLT) was assessed in the first 28-day cycle. Efficacy was assessed every 2 cycles. RESULTS: Thirty patients were enrolled between December 2011 and September 2013. In the dose escalation stage, 7 patients were enrolled in the 340 mg/m2 TH-302 cohort and 6 patients in the 480 mg/m2 TH-302 cohort. Ten patients were evaluable for DLT. DLTs included grade 2 intolerable esophagitis (n = 1) in the 340 mg/m2 TH-302 cohort, and grade 3 vaginal inflammation (n = 1) and grade 3 neutropenia with grade 3 thrombocytopenia (n = 1, same patient) in the 480 mg/m2 TH-302 cohort. The 340 mg/m2 TH-302 cohort was determined to be MTD and RPTD. The most common treatment-related adverse events were hematologic (anemia, neutropenia, and thrombocytopenia), nausea/vomiting, palmar-plantar erythrodysesthesia syndrome, constipation, fatigue, mucositis, anorexia, pain, and hypertension. Partial response (PR) was observed in 10% (n = 3) of patients, stable disease (SD) in 57% (n = 17), and progressive disease (PD) in 23% (n = 7). Due to toxicity, 3 patients were discontinued from study drug prior to first radiographic assessment but were included in these calculations. Disease control ≥6 months was observed in 37% of patients (n = 11). CONCLUSIONS: The RPTD for this novel combination is pazopanib 800 mg daily on days 1-28 plus TH-302 340 mg/m2 on days 1, 8 and 15 of each 28-day cycle. Preliminary activity was seen in treatment-refractory cancers and supports potential value of co-targeting tumor angiogenesis and tumor hypoxia.