Niall C. Tebbutt

Bevacizumab prolongs progression-free survival (PFS) in patients with metastatic colorectal cancer. We analysed the protein expression levels of vascular endothelial growth factor (VEGF) ligands and receptors to determine their prognostic and predictive effects. We graded expression of VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-R1, and VEGF-R2 to assess whether overexpression predicted bevacizumab resistance in samples from 268 of 471 patients randomised to capecitabine (C), capecitabine and bevacizumab (CB), or CB and mitomycin (CBM) in the MAX trial and extended the analysis to the CAIRO-2 population. Patients with low expression of VEGF-D (0, 1+) benefited from bevacizumab treatment (PFS hazard ratio (HR) (C vs CB+CBM), 0.21; 95% CI, 0.08–0.55; overall survival (OS) HR, 0.35; 95% CI, 0.13–0.90). Patients with higher VEGF-D expression received less benefit (VEGF-D 2+ PFS HR, 0.67; 95% CI, 0.45–1.00; OS HR, 0.82; 95% CI, 0.52–1.30; VEGF-D 3+ PFS HR, 0.77; 95% CI, 0.50–1.17; OS HR, 1.28; 95% CI, 0.79–2.09) (P interaction <0.05). In CAIRO-2, there was no difference in PFS or OS according to VEGF-D expression. The predictive value of VEGF-D expression for bevacizumab may depend on the chemotherapy backbone used. Further evaluation is required before clinical utilisation.

Aim: The PETACC-6 trial investigates the role of oxaliplatin in addition to preoperative chemoradiation (CRT) and adjuvant chemotherapy (CT) with capecitabine to improve disease-free survival (DFS) in locally advanced rectal cancer. Methods: Patients with rectal adenocarcinoma within 12 cm from the anal verge, T3/4 and/or node-positive, without evidence of metastatic disease, considered either resectable at the time of entry or expected to become resectable, were randomized to 5 weeks of preoperative CRT with capecitabine, followed by surgery and 6 cycles of adjuvant CT with capecitabine (standard control arm 1) or capecitabine + oxaliplatin before and after surgery (arm 2). 440 DFS events were required to have 80% power to detect an improvement in 3-year DFS from 65% to 72% (HR = 0.763), with two-sided alpha of 5% and allowing for an interim analysis for early efficacy at 200 events. Results: 1094 patients were randomized (547 in each arm). From 1081 eligible patients, 543 in arm 1 and 528 in arm 2 started preoperative treatment (3/528 patients without oxaliplatin in arm 2), and of these 77.3% and 72.6%) patients started postoperative chemotherapy within protocol. In arm 2, 11.8% patients did not receive the planned postoperative oxaliplatin. Major reasons for protocol discontinuation were progressive disease (3.9% in arm 1 vs. 3.8% in arm 2), toxicity (7.7% vs. 16.5%), surgery complication (8.7% vs. 9.1%), patient's refusal (5.9% vs. 10.8%). At planned interim analysis, the independent data monitoring committee recommended the early release of the results. At a median follow-up of 31months, 124 and 121 DFS events were observed in arm 1 and 2 (adjusted HR = 1.036, 95% CI: 0.81 -1.33, P = 0.78). 3-year DFS was 74.5% (95% CI: 70.1% - 78.3%) in arm 1 (which is higher than anticipated) vs. 73.9% (95% CI: 69.5% - 77.8%) in arm 2; conditional power under HR = 0.763 is only 7%. Less locoregional and distant failures were recorded in the experimental arm with oxaliplatin (95 in arm 2 vs. 109 in arm 1) but a higher rate of deaths without progression (26 in arm 2 vs. 15 in arm 1). Conclusions: Interim results at a median follow up of 2.6 y currently indicate no DFS-benefit for the addition of oxaliplatin to capecitabine-based CRT and adjuvant CT. However, with actually only 245 out of the required 440 events, final evaluation cannot be done before at least 2 further years follow-up. Disclosure: H.J. Schmoll: has a consultant or advisory relationship to disclose with Roche, Sanofi and Bayer; has honoraria to disclose from Roche; has research funding to disclose from Merck and Roche; K. Haustermans: has research funding to disclose from Roche; T.J. Price: has a consultant or advisory relationship to disclose with Roche; R. Hofheinz: has a consultant or advisory relationship to disclose with Roche; has honoraria and research funding to disclose from Roche; B. Brenner: has a consultant or advisory relationship to disclose with Sanofi-Aventis; has research funding to disclose from Sanofi-Aventis; J. Zalcberg: has a consultant or advisory relationship to disclose with Sanofi-Aventis and Roche; has honoraria, research funding and other remuneration to disclose from Sanofi-Aventis and Roche. M.P. Lutz: has a consultant or advisory relationship to disclose with Roche; E. Van Cutsem: has research funding to disclose from Roche and Sanofi.All other authors have declared no conflicts of interest.

Aim: Previous reports have described differences in biology and outcome based on whether the primary is right (R) or left (L) sided. Possible differences in response to biological agents have also been reported based on side of primary lesion.^1,2 We have previously published molecular markers from the MAX trial and here we have assessed the panel of markers based on right or left primary site. Methods: We analysed the MAX trial of capecitabine v capecitabine/bevacizumab (+/-mitomycin C) for differences in patient characteristics, molecular profile and outcomes based on whether the primary was R (caecum to transverse colon) or L (descending colon to rectum) sided. Survival outcomes were analysed using Kaplan-Meier curves and proportional hazards regression modeling. Results: 440 patients had primary site documented and were analysed for baseline characteristics. 298 patients had molecular results. 28% had R sided primary. Major differences between R and L respectively are as follows; female 49% v 33% (p < 0.01), prior history of diabetes 13% v 27% (p = 0.02), lung involvement 28% v 44% (p < 0.01), BRAF MT 16% v 3.5% (p = Conclusions: There are more negative prognostic factors in patients with R sided primary, in particular high BRAF MT, and these patients have inferior overall survival when compared to those with a L sided primary. There was no suggestion that site of primary had any impact on bevacizumab effect on PFS. ¹SY Brule et al, J Clin Oncol 31, 2013 (supp #3528) ²MK Boisen et al, Ann Oncol 24, 2554-59 Disclosure: T.J. Price: Advisory board for Roche. All other authors have declared no conflicts of interest.

Loss of phosphatase and tensin homologue (PTEN) function evaluated by loss of PTEN protein expression on immunohistochemistry (IHC) has been reported as both prognostic in metastatic colorectal cancer and predictive of response to anti-EGFR monoclonal antibodies although results remain uncertain. Difficulties in the methodological assessment of PTEN are likely to be a major contributor to recent conflicting results.

Gallbladder toxicity, including cholecystitis, has been reported with motesanib, an orally administered small-molecule antagonist of VEGFRs 1, 2 and 3; PDGFR; and Kit. We assessed effects of motesanib on gallbladder size and function. Patients with advanced metastatic solid tumors ineligible for or progressing on standard-of-care therapies with no history of cholecystitis or biliary disease were randomized 2:1:1 to receive motesanib 125 mg once daily (Arm A); 75 mg twice daily (BID), 14-days-on/7-days-off (Arm B); or 75 mg BID, 5-days-on/2-days-off (Arm C). Primary endpoints were mean change from baseline in gallbladder size (volume by ultrasound; independent review) and function (ejection fraction by CCK-HIDA; investigator assessment). Forty-nine patients received ≥1 dose of motesanib (Arms A/B/C, n = 25/12/12). Across all patients, gallbladder volume increased by a mean 22.2 cc (from 38.6 cc at baseline) and ejection fraction decreased by a mean 19.2% (from 61.3% at baseline) during treatment. Changes were similar across arms and appeared reversible after treatment discontinuation. Three patients had cholecystitis (grades 1, 2, 3, n = 1 each) that resolved after treatment discontinuation, one patient developed grade 3 acute cholecystitis requiring cholecystectomy, and two patients had other notable grade 1 gallbladder disorders (gallbladder wall thickening, gallbladder dysfunction) (all in Arm A). Two patients developed de novo gallstones during treatment. Twelve patients had right upper quadrant pain (Arms A/B/C, n = 8/1/3). The incidence of biliary “sludge” in Arms A/B/C was 39%/36%/27%. Motesanib treatment was associated with increased gallbladder volume, decreased ejection fraction, biliary sludge, gallstone formation, and infrequent cholecystitis. ClinicalTrials.gov NCT00448786

The use of bevacizumab in combination with fluoropyrimidine-containing chemotherapy is a well-established first-line and second-line treatment for patients with metastatic colorectal cancer (mCRC). However, there remains a need for reproducible, validated, inexpensive and accessible prognostic markers to aid treatment selection. The optimal treatment duration and the role of bevacizumab in certain patient subgroups, considered at particular risk of bevacizumab-mediated toxicity, also require further investigation. The aim of the ASCENT study [an Australian translational Study to evaluate the prognostic role of inflammatory markers in patients with metastatic ColorEctal caNcer Treated with bevacizumab (Avastin™)] is to evaluate the relationship between the host inflammatory response as measured by neutrophil/lymphocyte ratio (NLR) and treatment outcomes in patients with previously untreated mCRC receiving bevacizumab-based first- and second-line treatment.

Background: Methods: Results: Conclusion:

Background: This phase 1b study assessed the maximum tolerated dose (MTD), safety, and pharmacokinetics of motesanib (a small-molecule antagonist of VEGF receptors 1, 2, and 3; platelet-derived growth factor receptor; and Kit) administered once daily (QD) or twice daily (BID) in combination with erlotinib and gemcitabine in patients with solid tumors. Methods: Patients received weekly intravenous gemcitabine (1000 mg/m2) and erlotinib (100 mg QD) alone (control cohort) or in combination with motesanib (50 mg QD, 75 mg BID, 125 mg QD, or 100 mg QD; cohorts 1-4); or erlotinib (150 mg QD) in combination with motesanib (100 or 125 mg QD; cohorts 5 and 6). Results: Fifty-six patients were enrolled and received protocol-specified treatment. Dose-limiting toxicities occurred in 11 patients in cohorts 1 (n = 2), 2 (n = 4), 3 (n = 3), and 6 (n = 2). The MTD of motesanib in combination with gemcitabine and erlotinib was 100 mg QD. Motesanib 125 mg QD was tolerable only in combination with erlotinib alone. Frequently occurring motesanib-related adverse events included diarrhea (n = 19), nausea (n = 18), vomiting (n = 13), and fatigue (n = 12), which were mostly of worst grade < 3. The pharmacokinetics of motesanib was not markedly affected by coadministration of gemcitabine and erlotinib, or erlotinib alone. Erlotinib exposure, however, appeared lower after coadministration with gemcitabine and/or motesanib. Of 49 evaluable patients, 1 had a confirmed partial response and 26 had stable disease. Conclusions: Treatment with motesanib 100 mg QD plus erlotinib and gemcitabine was tolerable. Motesanib 125 mg QD was tolerable only in combination with erlotinib alone.Dusan Kotasek, Niall Tebbutt, Jayesh Desai, Stephen Welch, Lillian L Siu, Sheryl McCoy, Yu-Nien Sun, Jessica Johnson, Adeboye H Adewoye and Timothy Pric

3621 Background: With age the frequency of cancer and chronic disease increases. CRC is a common cancer and treatment with chemotherapy and biological agents will be a major health issue in the elderly. Methods: MAX, a three arm study of C vs CB vs CBM, found an improvement in PFS with addition of B (+/− M) to C. This analysis assesses effect of adding B (+/− M) to C on PFS, OS, RR, Dose delivered and toxicity in elderly patients (age >75y). Results: 21% were >75y. Number/Median age: C 37/78.5y, CB 32/78.7y, CBM 30/80.2y. Baseline characteristics were balanced. 88% commenced C dose of 2,000mg/m²/day, d1-14, q21 (61% for 75y v 20% 75y C/CB/CBM respectively was (%); vomiting 5/13/3, diarrhea 19/22/20, HT 0/3/3, thrombosis/thrombus/embolism 5/6/13, cardiac 0/6 (3 Gd5)/3. There was 1 perforation (Gd5) in C. Grade 2/3 HFS (%) was 38/59/53. One Gd 3/4 neutropenia episode in CB. Overall, toxicity rate similar to 75yrs compared to those 75 yrs. Significant improvement in PFS with addition of B to C was seen in the elderly group. There was no signal of increased toxicity, including rates of VTE/ATE for those age >75yrs.