Total neoadjuvant therapy with or without aflibercept in rectal cancer: 3-year results of GEMCAD-1402

BACKGROUND

The results of the Grupo Español Multidisciplinar en Cáncer Digestivo (GEMCAD)-1402 phase II randomized trial suggested that adding aflibercept to modified fluorouracil, oxaliplatin, and leucovorin (mFOLFOX6) induction, followed by chemoradiation and surgery, could increase the pathological complete response (pCR) rate in patients with high-risk, locally advanced rectal cancer. Here we update results up to 3 years of follow-up and evaluate the predictive value of consensus molecular subtypes identified with immunohistochemistry (IHC).

METHODS

Patients with magnetic resonance imaging-defined T3c-d and/or T4 and/or N2 rectal adenocarcinoma in the middle or distal third were randomly assigned to mFOLFOX6 induction, with aflibercept (mF+A; n = 115) or without aflibercept (mF; n = 65), followed by capecitabine plus radiotherapy and surgery. The risk local relapse, distant metastases, disease-free survival (DFS), and overall survival (OS) were estimated at 3 years. Selected samples were classified via IHC into immune-infiltrate, epithelial, or mesenchymal subtypes.

RESULTS

mF+A and mF had 3-year DFS of 75.2% (95% confidence interval [CI] = 66.1% to 82.2%) and 81.5% (95% CI = 69.8% to 89.1%), respectively; 3-year OS of 89.3% (95% CI = 82.0% to 93.8%) and 90.7% (95% CI = 80.6% to 95.7%), respectively; 3-year cumulative local relapse incidences of 5.2% (95% CI = 1.9% to 11.0%) and 6.1% (95% CI = 1.7% to 15.0%), respectively; and 3-year cumulative distant metastases rates of 17.3% (95% CI = 10.9% to 25.5%) and 16.9% (95% CI = 8.7% to 28.2%), respectively. pCRs were achieved in 27.5% (n = 22 of 80) and 0% (n = 0 of 10) of patients with epithelial and mesenchymal subtypes, respectively.

CONCLUSION

Adding aflibercept to mFOLFOX6 induction was not associated with improved DFS or OS. Our findings suggested that consensus molecular subtypes identified with IHC subtypes could be predictive of pCR with this treatment.

Phase II trial of neoadjuvant mFOLFOX 6 with panitumumab (P) in T3 rectal cancer with clear mesorectal fascia (MRF) and KRAS, NRAS, BRAF, PI3KCA wild type (4WT). GEMCAD 1601 PIER trial

3512

Background: Patients with advanced colorectal cancer with 4WT tumors achieve increased response rates with chemotherapy and anti-EGFR therapy as compared with chemotherapy alone. In clinically staged (c) T3 rectal cancer neoadjuvant oxaliplatin/fluoropyrimidine combination has shown to induce encouraging pathological complete response (pCR). We hypothesize that combining FOLFOX and P could improve outcomes in 4WT tumors. Methods: PIER was an investigator-initiated phase II, single-arm, multicentre clinical trial to evaluate the safety and efficacy of neoadjuvant mFOLFOX6 with P in pts < 75-y, with 4WT rectal cancer of the middle third staged as T3 by centrally-reviewed magnetic resonance imaging (MRI) and clear MRF, who were candidate for a R0 resection with sphincter preservation surgery. Pts received 6 cycles and underwent re-staging with MRI and sigmoidoscopy. Pts without progression underwent total mesorectal excision 4 weeks after the last cycle. Patients with progression were treated with pre-op chemoradiotherapy. The primary endpoint was pCR. The study followed a 2-Stage Simon’s MiniMax design (P0 of 16%, P1 of 35%, alpha and beta of 0.1). The target sample size was 35 patients and if 9 or more achieved a pCR, the results would be compatible with efficacy. We present primary and early secondary endpoints. Results: Between 9/2017 and 6/2020, 90 patients were screened (56 excluded; 42 were excluded due to mutations, 12 were excluded due to discrepancies with central review of radiology) of whom 34 were enrolled. In the ITT population a pCR was observed in 11 pts (32.3%; [95% CI 17.39-50.53]) and a near-complete pathological response (Mandard 1+2) was observed 17 pts (52.9%). Clinical complete or near complete response was achieved in 50% and there were no progressions. R0 resection rate and pathological circumferential resection margin neg- were 100%. Full compliance with induction was 88%. Neoadjuvant G3/4 toxicity occurred in 54% and was consistent with FOLFOX/P safety profile. G3/4 postoperative related toxicity was 19% with one reoperation. Conclusions: The study met the threshold for efficacy. mFOLFOX6 with P as neoadjuvant therapy can be effective and safe without unexpected toxicities in mrT3, clear MRF and 4WT rectal cancer and resulted in a higher rate of pCR compared with our previous series (GEMCAD 0801; The Oncologist 2014) in a similar molecular-unselected population. This study was funded by Amgen S.A. Clinical trial information: NCT03000374.

Limited Liver or Lung Colorectal Cancer Metastases. Systemic Treatment, Surgery, Ablation or SBRT

The prognosis for oligometastatic colorectal cancer has improved in recent years, mostly because of recent advances in new techniques and approaches to the treatment of oligometastases, including new surgical procedures, better systemic treatments, percutaneous ablation, and stereotactic body radiation therapy (SBRT). There are several factors to consider when deciding on the better approach for each patient: tumor factors (metachronous or synchronous metastases, RAS mutation, BRAF mutation, disease-free interval, size and number of metastases), patient factors (age, frailty, comorbidities, patient preferences), and physicians' factors (local expertise). These advances have presented major challenges and opportunities for oncologic multidisciplinary teams to treat patients with limited liver and lung metastases from colorectal cancer with a curative intention. In this review, we describe the different treatment options in patients with limited liver and lung metastases from colorectal cancer, and the possible combination of three approaches: systemic treatment, surgery, and local ablative treatments.

Phase II study of durvalumab plus total neoadjuvant therapy (TNT) in locally advanced rectal cancer: The GEMCAD-1703 DUREC trial

TPS4122

Background: In clinical stages II and III (cT3-4 and/or N+), preoperative chemoradiotherapy (CRT) or short-course radiation followed by total mesorectal escision (TME) have been the standard of care for the last 15 years. Induction chemotherapy (CT) before CRT (strategy known as TNT) results in fewer toxic effects and improved compliance. TNT may release tumor-neoantigens with platinum-based induction CT, and radiotherapy has the potential ability to induce an immunogenic cell death and counteract an immune-suppressive tumor microenvironment that provides the rationale for combining with immunotherapies. In addition, the presence of tumor infiltrating lymphocytes has been demonstrated in patients with rectal cancer treated with neoadjuvant CRT, reinforcing the rational for immune check-point inhibitors in this setting. We hypothesize that combining TNT with durvalumab (an optimized monoclonal antibody directed against programmed cell death-1 ligand 1) would improve outcome. Methods: DUREC is a multicenter, single-arm, open-label, phase Ib/II study for patients with magnetic resonance (mr) image middle or distal third, mrT3c-d/T4/N2 rectal adenocarcinoma. Treatment: Patients will receive 6 cycles of modified FOLFOX6 prior to CRT (capecitabine with 50.4 Gy in 28 fractions) and TME, combined with durvalumab 1500 mg every 4 weeks during induction CT, CRT and waiting period until surgery. To assess the tolerability and toxicity profile we plan to perform a run-in treatment phase including the first 6 patients in the study, holding recruitment until all of them will be operated and 30-days post-surgery period completed. If ≤ 2 durvalumab-related dose-limiting toxicities (DLTs) are observed, recruitment will continue. The primary objective is pathological complete response (pCR) rate. Secondary endpoints include toxicity, tumor regression grade, R0 resections, clear circumferential margins, surgical complications, NAR score, disease-free survival and a biomarker program on tumor tissue, blood samples and stool microbiota. Statistical design: 58 evaluable patients (assuming a P0 of 16% and a P1 of 30%, with 0.1 alpha and 0.1 beta); Study started recruitment on December 2019. Clinical trial information: 2018-004835-56 .

Randomized phase II trial of modified (m) FOLFOX6 induction chemotherapy with or without aflibercept before standard chemoradiotherapy (CRT) and total mesorectal excision (TME) in patients with high-risk rectal adenocarcinoma (HRRC): Final results of the GEMCAD 1402, and by molecular subtypes

4102

Background: Neoadjuvant chemotherapy (CT) followed by CRT and TME is a treatment option for clinically staged HRRC. The goal of the GEMCAD 1402 trial was to evaluate the benefit of adding an antiangiogenic drug to the neoadjuvant CT. The analysis of primary endpoint showed a better response rate in the experimental arm (Fernandez-Martos et al. Jama Oncol 2019). Here we present 3-year disease-free survival (DFS) and a retrospective analysis of consensus molecular subtypes by Immunohistochemistry (CMSs-IHQ). Methods: Patients (p) with middle or distal third, mrT3/T4/N2 rectal adenocarcinoma were randomly assigned (2:1), to mFOLFOX6 with (arm 1, n=115) or without Aflibercept (arm 2, n=65) prior to CRT (capecitabine with 50.4 Gy in 28 fractions) and TME. Tissue microarrays from 90 (58 arm1, 32 arm 2) p were stained for nine markers (CDX2, FRMD6, HTR2B, ZEB1, KER, MSH2, MSH6, PMS2 and MLH1) by IHQ using both semiquantitative and quantitative approaches. Cases were classified as CMS1-IHQ1, CMS-IHQ2/3 or CMS-IHQ 4 (immune, epithelial or mesenchymal subtypes). Results: In the intention-to-treat population after a median follow-up time of 38 months, 29 p (25%) in arm 1 had a DFS-related event, as compared with 14 p (21%) in arm 2 (HR 1.2063, 95% confidence interval 0.6374 to 2.2829, P=0.5644. The rate of DFS at three years was 75.2% (95% confidence interval, 66.1% to 82.2%) in arm 1 and 81.5% (95% confidence interval, 69.8% to 89.1%) in arm 2 (P=0.5638 by the exact stratified log-rank test). Overall 0/80/10 p were classified as CMS-IHQ1, CMS-IHQ2/3 or CMS-IHQ4 respectively. The pathological complete response (pCR) rate (ypT0N0) was achieved in 27.5% and 0% in epithelial and mesenchymal subtypes respectively. A trend towards worse survival for the mesenchymal subtype was observed. Conclusions: Adding aflibercept to induction mFOLFOX6 is not associated with an improvement in DFS. Our findings suggest that CMSs-IHQ subtypes could be predictive for pCR with this treatment strategy. Clinical trial information: NCT02340949 .

PIER trial: Neoadjuvant therapy with panitumumab (P) and mFOLFOX-6 in an enriched population of patients with T3 rectal adenocarcinoma of the middle third with clear mesorectal fascia

TPS875

Background: Retrospective data suggest that patients with advanced colorectal carcinoma wild-type (WT) for RAS, BRAF or Pi3K achieve increased response rates from anti-EGFR therapy as compared with mutated tumors. Neoadjuvant chemotherapy with oxaliplatin/fluoropyrimidine combination has shown to induce encouraging pathological complete response (pCR) in clinically staged T3 rectal cancer tumours (Schragg et al, JCO 2014 and Fernandez-Martos et al, The Oncologist 2014). We hypothesize this efficacy could be improved in a selected population (quadruple WT [4WT]) combining chemotherapy and anti-EGFR therapy. The objective is to assess the feasibility, efficacy and safety of neoadjuvant therapy with mFOLFOX-6 + P in rectal adenocarcinoma patients of intermediate risk and 4WT. Methods: PIER is a prospective, phase II, single-arm, multicentre, open-label clinical trial (NCT03000374). Key eligibility criteria include patients < 75 years with rectal adenocarcinoma in the middle third , clear mesorectal fascia, candidate for R0 resection with sphincter preservation surgery and absence of mutations in KRAS (exon 2 [codons 12/13], exon 3 [codons 59/61] and exon 4 [codon 117/146]), NRAS ( exon 2 [codons 12/13], exon 3 [codons 59/61] and exon 4 [codons 117/146]), BRAF (exon 15 [codon 600]) and PI3KCA in exons 9 and 20. All pre- and post-treatment MRI scans are centrally reviewed. Treatment: 6 induction cycles of mFOLFOX6 + P every 14 days. After the last cycle, a CT-scan, MRI and rectal endoscopy will be performed and patients will undergo TME surgery within 4 weeks +/- 1 week after the last dose. In case of progression patients will receive standard preoperative chemoradiation. The primary end point is pCR; key secondary end points include R0 resection rate, and clinical complete response. Statistical design: 42 evaluable patients (assuming a P0 of 16% and a P1 35%, with 0.1 alfa and 0.1 beta); 2-stage Simon’s optimal design. Enrolment in PIER is ongoing. Clinical trial information: NCT03000374.

MRI assessment and outcomes in patients receiving neoadjuvant chemotherapy only for primary rectal cancer: long-term results from the GEMCAD 0801 trial

Background

Primary chemotherapy has been tested as a possible approach for patients with high risk features but predicted clear mesorectal margins on preoperative MRI assessment. This study investigates the prognostic relevance of baseline and post-treatment MRI and pathology staging in rectal cancer patients undergoing primary chemotherapy.

Patients and methods

Forty-six patients with T3 tumour > =2 mm from the mesorectal fascia were prospectively treated with Neoadjuvant Capecitabine, Oxaliplatin and Bevacizumab prior to surgery between 2009 and 2011. The baseline and post-treatment MRI: T, Nodal and Extra-mural venous invasion (EMVI) status were recorded as well as post-treatment MRI Tumour regression grade (TRG) and modified-RECIST assessment of tumour length. The post-treatment pathology (yp) assessments of T3 substage, N, EMVI and TRG status were also recorded. Three-year disease-free survival (DFS) and cumulative incidence of recurrence were estimated by using the Kaplan-Meier product-limit method, and Cox proportional hazards models were used to determine associations between staging and response on MRI and pathology with survival outcomes.

Results

About 46 patients underwent neoadjuvant chemotherapy alone for high risk margin safe primary rectal cancer. The median follow-up was 41 months, 5 patients died and 11 patients experienced relapse (2 local, 8 distant and 1 both). In total 23/46 patients were identified with MRI features of EMVI at baseline. mrEMVI positive status carried independent prognostic significance for DFS (P = 0.0097) with a hazard ratio of 31.33 (95% CI: 2.3-425.4). The histopathologic factor that was of independent prognostic importance was a final ypT downstage of ypT3a or less, hazard ratio: 14.0 (95% CI: 1.5-132.5).

Conclusions

mrEMVI is an independent prognostic factor at baseline for poor outcomes in rectal cancer treated with neoadjuvant chemotherapy while ≤ypT3a is associated with an improvement in DFS. Future preoperative therapy evaluation in rectal cancer patients will need to stratify treatment according to baseline EMVI status as a crucial risk factor for recurrence in patients with predicted CRM clear rectal cancer.

Aflibercept (Z) in combination with FOLFIRI for second-line treatment of patients (pts) with metastatic colorectal cancer (mCRC): Safety and quality of life (QoL) data from the Spanish subgroup of the Aflibercept Safety and Quality-of-Life Program (ASQoP)

751

Background: In the VELOUR trial, adding Z to FOLFIRI improves OS, PFS and RR in mCRC pts progressing after oxaliplatin ±biologic agents. The ASQoP trial (NCT01571284) was designed to gather safety and QoL data from mCRC in real-life setting. We report data collected by the Spanish investigators. Methods: ASQoP is single-arm, open-label trial evaluating safety and QoL of Z in mCRC pts as 2nd line. Eligible pts received Z (4mg/kg) q2wks on day 1/cycle, followed by FOLFIRI (dosing was at physician’s discretion) until disease progression, unacceptable toxicity, death, or investigator/pt decision. The EQ-5D was used for utility index (UI) measure and the EORTC QLQ-C30 as generic cancer instrument. QoL population consisted of pts completing the questionnaire at baseline and ≥1 assessment post-baseline and received ≥1 part of 1 dose of study treatment. Results: The safety population comprised 77 pts with ≥1 completed cycle of treatment. Grade (G)3/4 AEs were reported in 72.7% of pts (vs 83.5% in VELOUR), being G3 most commonly reported. There was no G4 hypertension, stomatitis, or proteinuria. G4 Diarrhea was found in 1.3% of pts. Mean baseline UI was 0.7 (95% CI, 0.63-0.78) in 51 pts, and remained relatively stable at cycles 3 (n=39) and 7 (n=24), with a mean (±SD) change from baseline of 0.03 (±0.26) and -0.06 (±0.35), respectively. Mean baseline global health status score was 63.1 (95% CI, 55.8-70.4) in 54 pts, and remained stable up to cycle 9 with a mean (±SD) change from baseline of 4.17 (±38). Conclusions: Thisanalysis has identified no new safety signals and suggests an acceptable toxicity profile with a relatively stable UI and QoL in Spanish mCRC pts in the real-life setting. [Table: see text]

Randomised, open-label, phase II study of gemcitabine with and without IMM-101 for advanced pancreatic cancer

BACKGROUND

Immune Modulation and Gemcitabine Evaluation-1, a randomised, open-label, phase II, first-line, proof of concept study (NCT01303172), explored safety and tolerability of IMM-101 (heat-killed Mycobacterium obuense; NCTC 13365) with gemcitabine (GEM) in advanced pancreatic ductal adenocarcinoma.

METHODS

Patients were randomised (2 : 1) to IMM-101 (10 mg ml(-l) intradermally)+GEM (1000 mg m(-2) intravenously; n=75), or GEM alone (n=35). Safety was assessed on frequency and incidence of adverse events (AEs). Overall survival (OS), progression-free survival (PFS) and overall response rate (ORR) were collected.

RESULTS

IMM-101 was well tolerated with a similar rate of AE and serious adverse event reporting in both groups after allowance for exposure. Median OS in the intent-to-treat population was 6.7 months for IMM-101+GEM v 5.6 months for GEM; while not significant, the hazard ratio (HR) numerically favoured IMM-101+GEM (HR, 0.68 (95% CI, 0.44-1.04, P=0.074). In a pre-defined metastatic subgroup (84%), OS was significantly improved from 4.4 to 7.0 months in favour of IMM-101+GEM (HR, 0.54, 95% CI 0.33-0.87, P=0.01).

CONCLUSIONS

IMM-101 with GEM was as safe and well tolerated as GEM alone, and there was a suggestion of a beneficial effect on survival in patients with metastatic disease. This warrants further evaluation in an adequately powered confirmatory study.

Prospective biomarker validation trial evaluating the prognostic role of the combined expression of phospho-insulin growth factor receptor-1 and matrilysin in KRAS (exon 2) wild-type (WT) metastatic colorectal cancer (mCRC) patients treated with FOLFOX-6 plus panitumumab as first-line therapy [PULSE trial (GEMCAD 09-03)]

583

Background: Matrilysin can activate phospho-insulin growth factor receptor-1 (pIGF-1R) through IGFBP-3 degradation, releasing IGF-1. Matrilysin per se has shown poor prognosis in mCRC and the co-expression of matrilysin and pIGF-1R (double positivity, DP) correlates with poor prognosis in WT KRAS refractory patients (pts) treated with anti-EGFR in retrospective analyses. We performed a prospective clinical trial in WT KRAS (exon 2) pts, treated with FOLFOX plus panitumumab in first-line therapy to validate those findings. Methods: Positive cases were defined by immunohistochemistry as those with moderate or strong intensity (++/+++) and > 70% expression for both matrilysin and p-IGF-1R (antibody anti-pY1316). The primary end-point was progression-free survival (PFS). Seventy-eight pts and 56 events were required to have an 80% power to detect a difference in median PFS of 6 months (two-sided p< 0.05). Results: We screened 196 mCRC pts in 24 centers between Nov/2010 and Apr/2013 and 78 pts met inclusion criteria (42 non-DP and 36 DP). Median follow-up was 23 months. There were no differences in baseline characteristics [age, sex, liver metastases, lactate dehydrogenase (LDH) levels, performance status and BRAF mutational status] between both groups. There were no differences in the number of FOLFOX-6 and panitumumab cycles received. Cutaneous toxicity was more frequent in DP pts (p = 0.035). Response rate was 80.5% in non-DP and 72.2% in DP patients (p = 0.37). Median PFS (95% CI) was 7.4 months (95%CI 5.2-13.3) in non-DP and 9.6 months (95% CI 6.7-17.5, p = 0.15) in DP patients. Median overall survival was 19.8 months (11.5-26.3) in non-DP pts and 39.1 months (26-NE, p = 0.071) in DP pts. Adjusted HR for PFS was 0.68 (95% CI 0.41-1.12). Adjusted analysis for OS was 0.50 (95% CI 0.27-0.90). Conclusions: We found that co-expression of matrilysin and pIGF-1R is a novel strong prognostic biomarker of survival benefit in mCRC KRAS WT pts treated in first-line with FOLFOX-6 plus panitumumab. Clinical trial information: NCT01288339.

Radiologic and pathologic prognostic factors after neoadyuvant chemotherapy for T3 rectal cancer (RC): 3-year update GEMCAD 0801-trial

643

Background: Prognostic factors in RC treated only with neoadjuvant chemotherapy, have not been explored. We analized the prognostic value of clinical-radiological and pathological factors for disease-free, (DFS) and cumulative incidence of distant metastases (DM), for patients treated with preoperative capecitabine, oxaliplatin and bevacizumab (CAPOX-B) within our multicentre phase II GEMCAD 0801 trial. Methods: 46 patients were enrolled to evaluate safety and efficacy of neoadjuvant CAPOX-B followed by surgery. Results have been recently published (Oncologist 2014;19:1-2). Eligibility included baseline magnetic resonance (MR) showing a T3 tumour with mesorectal fascia potentially clear. Clinical, pathologic (ypN+, T or N downstaging, tumor regression grade [TRG], pathologic complete response [pCR]) and radiologic factors both at baseline (mr extramural venous invasion [EMVI]) and post neoadjuvant chemotherapy (ymr TRG, ymr lengh change [RECIST]), were analyzed. Univariate and multivariate analysis was performed. Results: With a median follow up of 36 months, fourteen patients experienced relapse (2 local, 11 distant, 1both). 3-year DFS was 69%. It was 95%/49% for T downstaging/no T downstaging (p=0.0009) and 95%/43% for mrEMVI positive/negative (p=0.0001), respectively. ymrTRG (Mandard) ranging from no regression, TRG 5, to complete response, TRG 1, p=0.0108 and ypN0/ypN+ (p=.02) were also significantly related to DFS in univariate analysis. The same factors and N-downstaging were also significant for cumulative incidence of DM. On Cox multivariate analysis, T downstaging and mrEMVI were the only independent prognostic factors for DM ( p=0.0363 and 0.0111 respectively) and DFS (p=0.0315 and 0.0277 respectively). Conclusions: T3 rectal cancer with MR detected EMVI positive and those without downstaging after neoadjuvant chemotherapy are associated with unfavourable prognosis. This suggests that future strategies for treatment intensification and surveillance could be based on EMVI and T staging. Clinical trial information: NCT00909987.

Preoperative chemotherapy in patients with intermediate-risk rectal adenocarcinoma selected by high-resolution magnetic resonance imaging: the GEMCAD 0801 Phase II Multicenter Trial

BACKGROUND

The need for preoperative chemoradiation or short-course radiation in all T3 rectal tumors is a controversial issue. A multicenter phase II trial was undertaken to evaluate the efficacy and safety of neoadjuvant capecitabine and oxaliplatin combined with bevacizumab in patients with intermediate-risk rectal adenocarcinoma.

METHODS

We recruited 46 patients with T3 rectal adenocarcinoma selected by magnetic resonance imaging (MRI) who were candidates for (R0) resection located in the middle third with clear mesorectal fascia and who were selected by pelvic MRI. Patients received four cycles of neoadjuvant capecitabine and oxaliplatin combined with bevacizumab (final cycle without bevacizumab) before total mesorectal excision (TME). In case of progression, preoperative chemoradiation was planned. The primary endpoint was overall response rate (ORR).

RESULTS

On an intent-to-treat analysis, the ORR was 78% (n = 36; 95% confidence interval [CI]: 63%-89%) and no progression was detected. Pathologic complete response was observed in nine patients (20%; 95% CI: 9-33), and T downstaging was observed in 48%. Forty-four patients proceeded to TME, and all had R0 resection. During preoperative therapy, two deaths occurred as a result of pulmonary embolism and diarrhea, respectively, and one patient died after surgery as a result of peritonitis secondary to an anastomotic leak (AL). A 13% rate of AL was higher than expected. The 24-month disease-free survival rate was 75% (95% CI: 60%-85%), and the 2-year local relapse rate was 2% (95% CI: 0%-11%).

CONCLUSION

In this selected population, initial chemotherapy results in promising activity, but the observed toxicity does not support further investigation of this specific regimen. Nevertheless, these early results warrant further testing of this strategy in an enriched population and in randomized trials.

Chemoradiation (CRT) followed by surgery and adjuvant capecitabine plus oxaliplatin (CAPOX) compared with induction CAPOX followed by concomitant CRT and surgery for locally advanced rectal cancer: Results of the Spanish GCR-3 randomized phase II trial after a median follow-up of 5 years

383

Background: In locally advanced rectal cancer in contrast with the conventional approach the administration of chemotherapy prior to chemoradiation (CRT) and surgery allow most patients receive planned treatment with better toxicity profile without compromising the pCR and complete resection rates, as we previously demonstrated. (J Clin Oncol 28:859-865, 2010). We now report on the 5-year outcomes of this randomized trial. Methods: Patients with distal or middle third, T3-T4 and/or N+ rectal adenocarcinoma selected by Magnetic Resonance +/- endorectal ultrasound, were randomly assigned to arm A—preoperative CRT followed by surgery and four cycles of postoperative adjuvant capecitabine and oxaliplatin (CAPOX)—or arm B— four cycles of CAPOX followed by CRT and surgery. The following five-year outcomes were assessed: the cumulative incidence of local-regional (LRF) and distance failure (DF), disease-free (DFS) and overall (OS) using the Kaplan-Meier method. Results: Of 108 patients accrued, 52 were randomly assigned to arm A and 56 to arm B. According to intention-to-treat analysis with a median follow-up time of 69.5 months, the 5-years DFS rates were 64.3% (95% CI, 49% to 76%) in arm A and 60.7% (95 CI, 46% to 72%) in arm B (P=0.73). The 5-year cumulative incidences of local relapse were 1.9 % and 7.1% in A and B arms respectively (P= 0.36). No significant differences were detected for 5-year cumulative incidence of distant metastases (21.1% and 23.2%; P = 0.80) and 5-years overall survival (77.9% and 74.7%; P= 0.64). Conclusions: Both approaches yield similar 5-y outcomes. Because of the associated acute toxicity sparing and better compliance with induction CT compared with adjuvant CT, integrating effective systemic therapy prior to CRT and surgery may well be the next step in phase III testing versus the standard strategy to capture meaningful differences in DFS.

Neoadjuvant capecitabine, oxliplatin, and bevacizumab (CAPOX-B) in intermediate-risk rectal cancer (RC) patients defined by magnetic resonance (MR): GEMCAD 0801 trial

3586

Background: Retrospective data suggest that RT might not be needed in all patients with stage II/III RC. Modern systemic therapy might have local efficacy similar to chemoradiation (CRT). Methods: A multicenter phase II trial was undertaken to evaluate safety and efficacy of neoadjuvant CAPOX-B in patients with T3 middle third rectal adenocarcinoma. Eligible patients (pts) had measurable disease at the baseline and candidate for R0 total mesorectal escision (TME) with intermediate-risk defined by pelvic MR a) T3 with distal border of tumor > 5 cm from the anal verge and below the sacral promontory. b) tumor ≥2 mm from the mesorectal fascia. Pts received 4 cycles of Cap 2000 mg/m2 (d1-14), Ox 130 mg/m2 (d1) and B 7.5 mg/kg (d1) every 3 weeks (last cycle without B). Pts undergo re-staging with MR. One radiologist reviewed all pre- and post-treatment MR scans independently. Pts without progression proceed to TME 4-6 weeks from the last cycle. If progression, pts were to be referred for pre-op cap/RT followed by TME. 1º Endpoint: Tumor Response (RECIST). Design: Simon 2-stage; 28 pts 1st stage and 46 pts 2nd stage. We report data on the planned analysis of pts included for 1st stage. Results: 28 eligible pts (10F/18M) were enrolled from 7/09-5/11. Tumor response, compliance and toxicity details are shown in table below. Two pN2 pts received postop Cap/RT. Conclusions: Neoadjuvant CAPOX-B is active and safe. Early parameters of efficacy are encouraging and seem similar to those observed with CRT. [Table: see text]

Pharmacogenetic predictors of adverse events in stage II-III colon cancer (CC) patients treated with oxaliplatin and fluoropyrimidines-based adjuvant chemotherapy (CT): A GEMCAD study

10547

Background: Although the benefit of oxaliplatin-based adjuvant CT has been demonstrated in patients with resected stage II-III CC, the recommendation to administer postoperative treatment must consider its potential adverse events. Predicting individual patients’risk of severe toxicity could potentially improve the quality of care by allowing individualization of treatment. We investigate the utility of determining single nucleotide polymorphisms (SNPs) in genes involved in oxaliplatin and fluoropyrimidines metabolisms to predict the toxicity of adjuvant CT in stage II-III CC patients. Methods: DNA was extracted from formalin-fixed paraffin-embedded samples from 379 surgically treated high-risk stage II (27.71%) and stage III (72.29%) CC patients receiving adjuvant CT (54.35% FOLFOX, 45.65% XELOX) from January 2004 to December 2008. Genotyping was performed for 35 SNP in 18 genes using the MassARRAY (SEQUENOM) technology. Results: A total of 89 (23.4%) patients experienced at least one grade 3-4 adverse event. The most common grade 3-4 toxicities were neutropenia (15.3%), diarrhea (8.17%) and neurotoxicity (7.65%). The MTHFR rs1801133 C>T C/C (30.1% C/C, 17.5% C/T, 21.7% T/T; p=0.043) and XRCC2 rs3218408 T>G T/T (28.3% T/T, 16.2% G/T and 10% G/G; p=0.007) genotypes were associated with higher risk of any grade 3-4 toxicities, whereas the incidence of severe toxicity was lower in patients with the UMPS rs3772807 G>C C/C (14% C/C, 21% C/G, 28.9% G/G; p=0.021) and DPYD rs970337 G>A A/A (16.7% A/A, 21.1% A/G, 30.1% G/G; p=0.028) genotypes. In addition, the DPYD rs970337 G>A A/A genotype was associated with a lower rate of grade 3-4 diarrhea (5% A/A, 9.4% A/G, 8.1% G/G; p=0.030), the ABCG2 rs3114018 A>C C/C genotype with an increased rate of grade 3-4 neutropenia (15.2% C/C, 6.3% A/C, 4.5% A/A; p=0.034) and the ERCC1 rs11615 T>C T/T genotype with a lower rate of grade 3-4 neurotoxicity (5.4% T/T, 9.1% C/T, 10.2% C/C; p=0.032). Conclusions: Our data suggest that SNPs in genes involved in oxaliplatin and fluoropyrimidines metabolisms can potentially predict severe toxicity in stage II-III CC patients treated with adjuvant CT.

Comparison of magnetic resonance imaging and histopathological response to neoadjuvant chemotherapy in locally advanced rectal cancer: The GEMCAD 0801 trial

e14097

Background: MRI methods for rectal cancer response assessment post chemoradiotherapy include post treatment T staging(ymrT), tumor regression grading(mrTRG) and length change/modified RECIST measurement. The usefulness of MRI in evaluating response to neoadjuvant chemotherapy has not been investigated. We assessed the reproducibility and agreement of these three parameters with histopathological T and TRG stage(ypT, pTRG). Methods: 28 eligible patients were enrolled in a prospective phase II trial to evaluate safety and efficacy of neoadjuvant CAPOX-B in patients with MRI defined T3 rectal adenocarcinoma. Patients received 4 cycles of Cap 2000 mg/m2(d1-14),Ox 130 mg/m2(d1) and B 7.5 mg/kg(d1) every 3 weeks(last cycle without B). Seven radiologists assessed MRIs using the following categories: ymrT (T0-T4 using T3 substaging), mrTRG (1-5), and length change(Stable disease, Complete response,Partial response). Agreement was assessed by kappa (central reviewer data verses each local centre reviewer).Agreement between central reviewer MRI results and both pathology endpoints was also assessed. Results: 24 patients had evaluable pre and post chemotherapy imaging and pathology (4 did not have post treatment MRI). Thirteen patients had good response (ypT0-3a) and 11 had poor response (>ypT3a). Sixteen patients had good pTRG(2-4) and 8 had poor pTRG(0&1). ymrTRG showed a moderate level of reproducibility;K=0.45-0.58. ymrT showed a fair to moderate level of agreement;K=0.2-0.53. Length assessment also showed a fair level of agreement; K=0.21-0.38. ymrTRG showed 75% agreement with ypT(16/22); K=0.49(0.13-0.84) and 79% agreement with pTRG(19/24); K=0.55(0.22-0.88). ymrT showed a fair level of agreement with ypT;K=0.21, pTRG;K=0.2, length assessment showed slight agreement with ypT;K=0.1, pTRG;K=0.1. Conclusions: This is the first study to show MRI can evaluate response of rectal cancer following neoadjuvant chemotherapy. As mrTRG showed best agreement with pathology, we recommend mrTRG as the preferred method of post treatment assessment in this setting.

Incidence and patterns of phospho insulin growth factor receptor-1 (pIGF-1R) and matrilysin (MMP7) expression in metastatic colorectal cancer (mCRC), and correlation with KRAS status: A prospective evaluation in the PULSE trial—A GEMCAD study

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Background: MMP7 can activate IGF-1R by IGF release due to IGFBP degradation. Activation of IGF-1R can contribute to EGFR resistance by transactivation. We previously described that concomitant expression of p-IGF-1R and MMP7 (Double positive; DP), correlates with poor prognosis, in KRAS WT patients (pts) treated with anti-EGFR compounds (Horndler el al, 2011). Therefore we designed a prospective clinical trial to validate DP as a marker of resistance in KRAS WT pts treated in first-line therapy with FOLFOX-6 plus panitumumab. Methods: mCRC pts in the ongoing prospective PULSE trial (NCT0128833) were prospectively evaluated for p-IGF-1R (p-1316), MMP7 expression and KRAS mutational status. Pts defined as DP should express MMP7 (++ or +++ intensity in >66% of tumor cells) and p-IGF-1R (++ or +++ intensity in >66% of tumor cells). KRAS pts with mutations at exon 2 were excluded. The study was designed to include 40 pts in the two groups (DP vs non-DP) to detect a Hazard ratio difference in PFS of <0.5 (DP vs non-DP) with 80% power. Results: From November 2010 to December 2011, 113 consecutive pts were screened from 24 Spanish Institutions. 54 KRAS WT (40 pts non-DP and 14 DP) have been included. The non-DP arm has being recently closed for inclusion, due to pre-planned complete accrual. Among DP pts, 27% were KRAS WT and 30% KRAS mutant; p=0.63. 48% of cases were positive for p-IGF-1R. Phospho-IGF-1R positive cases had different patterns of staining: peri-nuclear in 76%, 11% nuclear and only 13% membrane-apical staining. These patterns do not differ between KRAS WT; (n=70) and KRAS mutant pts (n=43) (p=0.60). Tumors with positive p-IGF-1R expression, independently of the pattern, have higher MMP7 co-expression (59%) compared with negative cases (13%) (p<0.0001). Conclusions: MMP7 contributes to activate IGF-1R pathway in pts with mCRC. Internalization of the activated IGF-1R, could explain in part, the lack of efficacy of IGF-1R inhibitors in mCRC clinical trials.

Pharmacogenetic profiling for oxaliplatin-based adjuvant chemotherapy (CT) benefit in stage II-III colon cancer (CC) patients: A GEMCAD study

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Background: Identifying molecular biomarkers for tumour recurrence is critical in successfully selecting early-stage CC patients who are more likely to benefit from adjuvant CT. We tested whether single nucleotide polymorphisms (SNP) within genes involved in biological pathways of interest for CC progression and treatment resistance would predict the risk of recurrence in stage II-III CC patients treated with oxaliplatin and fluoropyrimidines-based adjuvant CT. Methods: Genomic DNA was extracted from formalin-fixed paraffin-embedded samples from 202 surgically treated high-risk stage II (29.7%) and stage III (70.29%) CC patients receiving adjuvant CT (25.24% FOLFOX, 74.75% XELOX) from January 2004 to December 2008. Minimum follow-up was 36 months. Genotyping was performed for 62 SNPs in 31 genes using the MassARRAY (SEQUENOM) technology. Our results were validated in an independent cohort of 177 stage II-III CC. Results: After a median follow-up of 51.4 months (7-96), 63 patients (31.18%) had experienced a relapse and 31 (15.34%) had died. Three-year disease-free survival (DFS) and overall survival (OS) were 72.2% (+/-0.032) and 89.1% (+/-0.022), respectively. Multivariate analysis showed that the risk of recurrence for patients with the E-selectine rs3917412 G>A G/G genotype was higher than for those with any A allele genotype [relative risk (RR): 2.02, 95% confidence interval (CI): 1.09-3.73, p=0.024]. In haplotype analysis, patients harboring the E-selectine rs3917412 G>A G/G and methylentetrahydrofolate reductase (MTHFR) rs1801133 C>T T/T haplotype had a higher risk of developing tumor recurrence compared to the E-selectine rs3917412 G>A any A and/or MTHFR rs1801133 C>T any C haplotype (RR: 3.39, 95% CI, 1.51-7.62, p=0.003). The ability to predict recurrence of this combined analysis was independently validated in the second cohort (RR: 3.75, 95% CI, 1.32-10.68, p=0.013). Conclusions: E-selectine and MTHFR SNPs were found to be independent prognostic markers for stage II-III CC patients, suggesting that this combined analysis provides additional prognostic information to that offered by clinicopathologic variables.

Multicenter randomized phase II study of chemoradiation (CRT) followed by surgery (S) and chemotherapy (CT) versus induction CT followed by CRT and S in high-risk rectal cancer: GCR-3 final efficacy and safety results

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Background: In locally advanced RC the optimal therapeutic sequence remains an important clinical question. Induction CT prior to CRT and S may be associated with better efficacy and compliance. Methods: Eligible pts had medium or distal high risk RC defined by MRI and/or US: Tumors within 2mm of mesorectal fascia, distal T3 at/below levators, resectable T4 and T3N+. Pts, stratified by center, were randomized assigned to receive either Arm A : capecitabine (Cap) 825 mg/m2 BID 5 d/w, oxaliplatin (Ox) 50 mg/m2 IV weekly x 5 and concomitant RT: 50.4 Gy in 28 fractions. S was planned 5–6 w after CRT. Post-op four cycles of Cap 1,000 mg/m2 bid days 1 to 14; Ox 130 mg/m2 day 1 or Arm B: Induction CapOx followed by CRT and S. Two parallel, Simon 2-stage designs: α=0.05 β=0.1; 24 evaluable pts/arm 1st stage and 54 pts/arm for 2nd stage. Primary endpoint: pathological complete response (pCR). Secondary endpoints included toxicity and treatment compliance. Results: 108 Pts were randomly assigned (arm A/B, 52/56), and 103 were assessable (49/54) from 14 sites. Median age 62/60 years, Male 65/70%. During treatment period 6 pts died A/B: 2 vascular, 1 suicide/ 3 post-op. Pts with any grade ¾ toxicity during CRT were arm A/B: 29% (14/49) and 23% (12/53). Any grade ¾ toxicity during adjuvant/induction CT were 51% (19/37) and 17% (9/54); χ2,p= 0.0004. On an intent-to-treat basis the pCR for Arm A/B was achieved in seven (13.5%; 95% CI, 5.6%-25.8%) and eight (14.3%; 95% CI, 6.4%-26.2%). R0 resections were achieved in 92% (45/49) and 88% (48/54). 51% (25/49) and 93% (50/54) received all four cycles of adjuvant/induction CT (χ2;p<0.0001). Relative Median Dose intensity of adjuvant /induction CT was 0.74/0.96 (Wilcoxon; p<0.0001) for Cap and 0.75/1.0 (Wilcoxon; p<0.0001) for Ox. Conclusions: Induction CT prior to CRT has more favorable compliance and toxicity profiles. Furthermore, there is no compromise in pCR and R0 resection rates. Larger trials evaluating this strategy are justified.

[Table: see text]

Coexpression of matrix metalloproteinase-7 (MMP7) and phosphorylated insulin growth factor receptor I (pIGF-IR) as predictors of resistance to anti-EGFR therapy in advanced colorectal cancer (ACRC): A GEMCAD study

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Background: IGF-IR is supposed to have anti-apoptotic and mitogenic properties in colorectal cancer and by transactivation can promote EGFR phosphorylation. MMP-7 is produced by colorectal cancer cells and by degrading IGFBP-3 can activate IGF-IR. Methods: We retrospectively investigated the role of pIGF-IR immunoreactivity (IHC) (Rubini) and MMP-7 IHC in primary CRC or metastases, to predict response rate (RR), progression free survival (PFS) and overall survival (OS) in ACRC patients (pts) treated with either cetuximab or panitumumab as second or third line therapy. RAS mutational status of codons 12/13 was determined using quantitative PCR-based assay. CT scans were done every 1.5–2 months (m) until progressive disease. Results: A total of 99 pts with available tissue from 168 pts with ACRC treated with anti-EGFR therapy in 4 Spanish Institutions, were analysed for RAS mutational status, pIGF-1R and MMP-7. There were no major differences in RR (18.8 vs 16%), PFS [3.3 vs. 3.1 months (m)] and OS (7.7 vs. 7m) between the whole and selected cohort. Fifty-seven (57.6%) pts were male, the median age was 62 (range 34–79) years, the median number of previous chemotherapy lines was 2 (range 1–3) and PS was distributed as follow: PS0, 17 (17.2 %) pts; PS1, 66 (66.7%) pts and PS2, 16 (16.2%) pts. Expression of MMP-7 and pIGF-1R were observed in 48 (48.5%) and 52 (52.5%) pts respectively. Co-expression of MMP-7 and pIGF-1R [Double Positive (DP)] was observed in 26 (26.3 %) pts and in 16 (24%) out of 66 RAS wild-type (WTRAS) pts. There was no association between RAS mutational status and DP (p=0.52). DP progressed more than non-DP pts both in the overall sample (73 vs. 43%, p=0.028) and in WTRAS pts (75 vs. 32%, p=0.011). In the subset of WTRAS pts, DP pts also have a poorer OS: 6.4 (95% CI 5.8–7.1) m vs. 8.6 (95%CI 6.0–11.3) m (p=0.005), and a trend for worse PFS 2.7 vs 4.0 m (p=0.11). Conclusions: Co-expression of pIGF-1R and MMP7 is associated with resistance to anti- EGFR therapy in WTRAS pts. Our study suggests that pts with WTRAS and DP could be a target population to assay new anti-IGF-1R compounds.

No significant financial relationships to disclose.

Preoperative uracil/tegafur and concomitant radiotherapy in locally advanced rectal (LAR) cancer: Updated results with a median follow-up of 5 years and analysis of prognostic factors (PF)

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Background: Preop chemoradiotherapy (CRT) with CI 5-FU is a standard of care for LAR cancer. Oral fluoropyrimidines, an attractive alternative to intravenous 5-FU, are perceived by patients as more convenient. Methods: We performed a phase II study in patients with potentially resectable tumors, localized in middle or distal rectum, ultrasonographically staged as T3 or T4 or N+ who were treated with UFT (400 mg/m2/d, 5 days a week for 5 weeks) and concomitant RT to the pelvis (45 Gy; 1.8 Gy/d over 5 weeks). Pts underwent surgery 5 to 6 weeks later followed by four cycles of 5-FU/LV (Mayo Clinic Scheme). Early end points of efficacy (pCR, downstaging, sphincter preserving surgery) and toxicity have already been reported (JCO 2004;22:3016). We now present data on secondary objectives (RFS, DFS and OS) and univariate and multivariate analysis of clinical and pathological PF. Results: 94 patients were included and complete information on 88 (94%) is availablewith a median follow-up of 5 years (60.4 months). Actuarial Kaplan-Meier DFS, RFS and OS are 61%, 66%, and 70 %. Patterns of failure are 7% pelvic and 25% distant. Univariate analysis results are shown in the table . Survival rate was also higher among patients with no or few residual disease after CRT but did not reach statistical significance. In Cox multivariate analysis both ypT and ypN are independent PF for DFS and RFS but only ypT is an independent PF for OS. Conclusions: This approach with preop UFT/RT reproduces the results that have been accomplished with 5-FU. ypT and ypN could be helpful to identify different risk groups and to select adjuvant treatments.

[Table: see text]

No significant financial relationships to disclose.

FOLFOX alternated with FOLFIRI as first-line chemotherapy for metastatic colorectal cancer

BACKGROUND

5-fluorouracil (5-FU), irinotecan, and oxaliplatin are the most active drugs in advanced colorectal cancer (CRC), and survival is improved with patient exposure to all of them. The efficacy and safety of an alternating schedule of continuous-infusion 5-FU with leucovorin (LV) plus oxaliplatin (ie, FOLFOX regimen) or irinotecan (ie, FOLFIRI regimen) was assessed in the first-line setting.

PATIENTS AND METHODS

Seventy-nine patients with previously untreated, unresectable CRC were included. Treatment consisted of 5-FU/LV (de Gramont schedule) plus oxaliplatin (85 mg/m2) alternated biweekly with the same 5-FU/LV regimen plus irinotecan (180 mg/m2). Treatment was maintained until tumor progression or unacceptable toxicity was noted.

RESULTS

Median age was 62 years. Performance status was 0/1 in 91% of patients, 63% had 1 organ involved, and 80% had liver metastases. A median of 6 courses per patient (range, 1-9) and a total of 952 infusions were given. The most frequent grade 3/4 toxic events were neutropenia (32%), diarrhea (26%), and asthenia (7%). Grade 1/2 neurotoxicity was seen in 59% of cases, but no grade 3/4 neurotoxicity was observed. There were no toxic deaths. An objective response rate of 54% (4 complete responses plus 39 partial responses) was attained. Median time to progression and overall survival were 13 months and 18 months, respectively.

CONCLUSION

This alternating schedule is active, with efficacy results similar to those seen with sequential protocols, the advantages of less toxicity, and 100% patient exposure to irinotecan and oxaliplatin.

A preliminary report of a phase II trial. UFT plus oral folinic acid as therapy for metastatic colorectal cancer in older patients. Spanish Group for the Treatment of Gastrointestinal Tumors (TTd Group)

The oral fluoropyrimidines have proved to be active in colorectal cancer in Japan and, recently, in the United States and Europe. Continuous oral administration simulates protracted fluorouracil (5-FU) continuous intravenous infusion. The purpose of this trial was to evaluate the tolerability and potential advantages of oral treatment for colorectal cancer in the elderly. The main inclusion criterion was age over 72 years. Patients were treated with UFT (tegafur plus uracil) 400 mg/24 hours (fixed doses) continuously plus folinic acid 45 mg/24 hours until toxicity. If grade 3 or 4 toxicity appeared, treatment was stopped until recovery. From September 1994 to November 1996, 126 patients were included. For the analysis in November 1996, 77 patients were evaluable for response, toxicity, and survival. The patients, including 34 women and 43 men, had a median age of 74 years (range, 72 to 82 years of age). The Karnofsky performance status was 60% to 80% for 41 patients and 90% to 100% for 36 patients. Liver metastasis was present in 48% of the cases, and 42% were locoregional and peritoneal. Toxicity was mild, with only one patient having grade 3 thrombocytopenia, 11 (14%) grade 3 or 4 nausea/vomiting, seven (9%) grade 3 or 4 diarrhea, and one grade 3 mucositis. Four patients (5%) had complete responses and nine (11.6%) partial responses, for an objective response rate of 16.9% (95% confidence interval, 9% to 27%). Twenty-two patients (28.6%) showed no change. The number of patients in whom disease did not progress (ie, patients with complete plus partial responses plus those with stable disease) was 35 (45.4%) (95% confidence interval, 34% to 57%). With a maximum follow-up of 24 months, the median actuarial survival is 14.4 months. The number without disease progression and the median survival in this preliminary analysis suggests that this schedule is a moderately effective, comfortable, treatment with only mild toxicity, that can be recommended for use in the elderly, and it warrants further study.