Phase II study evaluating trifluridine/tipiracil + bevacizumab and capecitabine + bevacizumab in first-line unresectable metastatic colorectal cancer (mCRC) patients who are noneligible for intensive therapy (TASCO1): Results of the final analysis on the overall survival

14

Background: Our phase II randomized study was conducted in patients with previously untreated unresectable mCRC not eligible to receive standard oxaliplatin- or irinotecan- based chemotherapy regimens. The results of the primary study analysis were reported earlier and demonstrated a promising efficacy in terms of progression-free survival (PFS) and an acceptable safety profile for the combination of trifluridine/tipiracil + bevacizumab (E. Van Cutsem et al. Ann. Oncol. 2020). Here we present the final end-of-study analysis on the overall survival (OS). Methods: Eligible patients were randomized in 1:1 ratio to receive either trifluridine/tipiracil administered orally at 35 mg/m²/dose bid from days 1-5 and days 8-12, and bevacizumab at 5 mg/kg on days 1 and 15 of a 28-day treatment cycle (TT-B), or capecitabine administered orally at 1250 or 1000 mg/m²/dose bid (according to the patient’s status) from days 1-14 and bevacizumab at 7.5 mg/kg on day 1 of a 21-day treatment cycle (C-B). Cycles were repeated until documented disease progression, unacceptable toxicity, or investigator’s/patient’s decision. Following the treatment discontinuation, all patients were followed for OS until the end-of-study, which was defined as the date of the withdrawal visit for the last patient. In the absence of death confirmation or for patients alive as of the end-of-study date, survival time was censored at the date of their last study follow-up. For the OS analysis the HR and the corresponding 2-sided 80% and 2-sided 95% CIs for TT-B versus C-B were estimated using a Cox proportional hazard model adjusting for the stratification factors based on IWRS data. OS was summarized using Kaplan-Meier curves and further characterized in terms of the median and survival probabilities at 6, 12, 18, and 24 months along with the corresponding 2-sided 80% and 2-sided 95% CI (Brookmeyer and Crowley CI for median and Kalbfleisch and Prentice CI for survival probabilities). Results: From April 2016 to March 2017, 153 patients were randomized and followed until end-of-study on September 1, 2020. Twenty-one patients, 11 from TT-B and 10 from C-B, were alive and censored for the analysis. Median OS was 22.31 months in TT-B and 17.67 months in C-B with HR 0.78 (95% CI, 0.55, 1.10). Survival probability at 18 months in TT-B was 0.62 (95% CI, 0.50, 0.72), and 0.47 (95% CI, 0.35, 0.57) in C-B. Conclusions: Our study demonstrated earlier a median PFS of 9.2 months for TT-B and 7.8 months for C-B when administered to patients with previously untreated unresectable mCRC ineligible for standard combination chemotherapy. The final study analysis performed on OS, the main secondary endpoint, provided further evidence for TT-B as a noteworthy valuable regimen in this population settings. Clinical trial information: NCT02743221.

Trifluridine/tipiracil plus bevacizumab in patients with untreated metastatic colorectal cancer ineligible for intensive therapy: the randomized TASCO1 study

BACKGROUND

We designed an open-label, noncomparative phase II study to assess the safety and efficacy of first-line treatment with trifluridine/tipiracil plus bevacizumab (TT-B) and capecitabine plus bevacizumab (C-B) in untreated patients with unresectable metastatic colorectal cancer (mCRC) who were not candidates for combination with cytotoxic chemotherapies.

PATIENTS AND METHODS

From 29 April 2016 to 29 March 2017, 153 patients were randomly assigned (1:1) to either TT-B (N = 77) or C-B (N = 76). The primary end point was progression-free survival (PFS). The primary PFS analysis was performed after 100 events (radiological progression or death) were observed. Secondary end points included overall survival (OS), quality of life (QoL; QLQ-C30 and QLQ-CR29 questionnaires), and safety.

RESULTS

Median (range) duration of treatment was 7.8 (6.0-9.7) months and 6.2 (4.1-9.1) months in the TT-B and C-B groups, respectively. Median (range) PFS was 9.2 (7.6-11.6) and 7.8 (5.5-10.1) months, respectively. Median (range) OS was 18 (15.2 to NA) and 16.2 (12.5 to NA) months, respectively. QoL questionnaires showed no relevant changes over time for either treatment. Therapies were well tolerated. Patients receiving TT-B had more grade ≥3 neutropenia (47% versus 5% with C-B). Patients receiving C-B had more grade ≥3 hand-foot syndrome (12% versus 0% with TT-B) and grade ≥3 diarrhea (8% versus 1% with TT-B), consistent with the known safety profiles of these agents.

CONCLUSION

TT-B treatment showed promising clinical activity in untreated patients with unresectable mCRC ineligible for intensive therapy, with an acceptable safety profile and no clinically relevant changes in QoL.

CLINICAL TRIAL INFORMATION

NCT02743221 (ClinicalTrials.gov).

Perioperative trastuzumab and pertuzumab in combination with FLOT versus FLOT alone for HER2 positive resectable esophagogastric adenocarcinoma: Petrarca—A phase II trial of the German AIO

TPS4133

Background: Neoadjuvant or perioperative chemotherapy has become a standard of care for locally advanced, resectable gastric cancer and adenocarcinoma of the GEJ. However, patient’s outcome is still unsatisfactory and 5-year survival, even in prospective trials, has been below 40%. Targeting HER2 with Trastuzumab and Pertuzumab prolonged survival in patients with HER2-positive advanced breast cancer as did Trastuzumab in patients with HER2-positive advanced gastric cancer. This provides a rationale for the evaluation of anti-HER2 treatment for resectable patients. Methods: This is a prospective, multicenter, randomized, investigator initiated phase II trial. Patients with HER2-positive locally advanced adenocarcinoma of the stomach and GEJ (i.e. ≥cT2 any N or any T N-positive) with exclusion of distant metastases are enrolled. HER2 status is centrally assessed. Patients are randomized 1:1 to 4 pre-operative 2-week cycles (8 weeks) of FLOT (Docetaxel 50 mg/m²; Oxaliplatin 85 mg/m²; Leucovorin 200 mg/m²; 5-FU 2600 mg/m²) followed by surgery and 4 additional cycles of FLOT (arm A); or the same therapy in combination with Trastuzumab 8/6 mg/kg and Pertuzumab 840 mg every 3 weeks pre- and postop, followed by a total of 9 additional cycles of Trastuzumab/Pertuzumab monotherapy (arm B). Primary endpoint of the phase II part (n = 100) of the trial is to show numerical improvement of the rate of pathological complete remission to approx. 25% with antibodies compared to approx. 16% with FLOT alone as assessed by a centralized pathology. Main secondary endpoints are safety and tolerability. Once results from phase II become available, study transition into phase III will be evaluated based on de facto results and current medical standards. Recruitment has already started; by February 2017 a total of 19 patients have been randomized. EudraCT: 2014-002695-86 Clinical trial information: NCT02581462.

SIRFLOX: Differences in site of first progression between mFOLFOX6 ± bevacizumab (bev) versus mFOLFOX6 ± bev + selective internal radiation therapy (SIRT) in first-line patients (pts) with metastatic colorectal cancer (mCRC)

637

Background: SIRFLOX, an international multi-centre open-label RCT in first-line pts with non-resectable, liver-only or liver-dominant mCRC, showed that compared to FOLFOX (± bev) chemotherapy alone [arm A] FOLFOX (± bev) plus SIRT using Y-90 resin microspheres [arm B] did not improve overall PFS (median 10.2 v 10.7 months arm A v B, HR: 0.93; 95% CI 0.77–1.12; p = 0.429). However, liver PFS by competing risk analysis was improved with the addition of SIRT (median 12.6 v 20.5 months in arm A v B, HR: 0.69; 95% CI 0.55–0.90; p = 0.002). The current analysis examines patterns of disease progression and potential impact on the primary study endpoint. Methods: Site and pattern (intra/extra-hepatic) of first progression, and whether progression was due to growth of existing lesions or the appearance of new lesions, was judged by an independent reader blinded to study arm. Results: From Oct 2006 to Apr 2013, 530 pts were randomised (arm A, n = 263; arm B, n = 267); 212 (40%) had extra-hepatic metastases at study entry; 292 (55%) were stratified to receive bev. As of 31 Jan 2015, the total number of patients with disease progression in arm A v B were 178 and 166, respectively. The site of first progression was more frequently in the liver (± other sites) in arm A v B (92.1% v 72.3%; p < 0.001). Conversely, site of first progression was less frequent in the lung (± other sites) in arm A v B (19.1% v 42.8%; p < 0.001). A higher proportion of first progression occurred in the liver alone in arm A v B (77.0% v 52.4%; p < 0.001). Conversely, a lower proportion of first progression occurred only in non-liver sites, primarily lung, in arm A v B (7.9% v 47.7%; p < 0.001). Of patients with first progression in the liver, a higher proportion occurred in existing liver lesions (± extrahepatic sites) in arm A v B (72.5% v48.2%; p < 0.001). Conclusions: The addition of SIRT to FOLFOX chemotherapy alone (± bev) reduced the frequency at which first disease progression occurred in the liver. Where first progression did occur in the liver, the addition of SIRT led to this more frequently being due to the appearance of lesions not evident on baseline imaging. Clinical trial information: NCT00724503.

Abstract B61: Exploratory analyses of the randomized phase 2 IMPACT study: Patients with response to prior induction chemotherapy have improved outcome when treated with the TLR-9 agonist MGN1703

Background: The international randomized (2:1) double-blind placebo-controlled phase 2 IMPACT trial recruited patients with metastatic colorectal cancer (mCRC) and disease control after induction with 1st-line chemotherapy +/- bevacizumab. The trial aimed to assess the clinical efficacy, safety, and immunological effects of the immunomodulator MGN1703, a potent Toll-Like Receptor 9 (TLR9) agonist, given at the dose of 60 mg subcutaneously twice weekly as switch maintenance after 4.5 to 6 months of induction therapy.

Methods: After randomization of 59 patients (43 MGN1703, 16 placebo) the trial was prematurely closed. The final analysis showed superiority of MGN1703 over placebo with hazard ratios (HR) for the primary endpoint PFS on maintenance of 0.55 (p=0.041) and 0.56 (p=0.070) by local investigator assessment or independent radiological review, respectively. Some delayed and long term responses were observed, 3 still ongoing in excess of 36 months. Exploratory PFS analyses of pretreatment characteristics identified patients with objective response (HR=0.39, p=0.0051), normalized CEA (HR=0.07, p&lt;0.0001), and the presence of activated NKT-cells (CD3+/CD56+/CD69+) (HR=0.26, p=0.0017) at the end of induction chemotherapy to benefit the most from maintenance with MGN1703. Since PFS is not considered the best endpoint to assess the benefit of immunotherapies, we analyzed the impact of these factors on the secondary endpoint overall survival (OS).

Results: Despite a median follow up of 17.7 months at the time of final study analysis, the OS data were not mature with only 35% and 50% of patients in the MGN1703 arm and placebo arm with an event, respectively. The power of the following OS analyses is therefore limited and will require confirmation when a large majority of events has been observed. The HR for the whole study ITT population was 0.63 (median 22.6 vs. 15.1 months for MGN1703 vs. placebo; p=NS). The subgroup of patients who were randomized into the study after achieving a RECIST response to prior induction therapy had HR of 0.40 (median 24.5 vs. 15.1 months; p=NS). Patients randomized in the study with stable disease had instead no benefit (HR 1.57; p=NS). The HR for OS of patients with presence of activated NKT cells and normalized CEA level after induction therapy was 0.43 and 0.69, respectively. Overall these results appear in line with the evidence from PFS subgroup analyses suggesting that responders may benefit the most from switch maintenance treatment with MGN1703. Recent literature provides a rationale for such finding, as a large series showed that presence of high density of lymphocyte infiltration in CRC metastases strongly predicts responses to chemotherapy (Halama et al, Cancer Res 2011; 71:5670-5677). A good response to chemotherapy may thus be a surrogate marker for increased immunogenicity of the tumor and allow identifying patients with an immune system that may be able to control tumor progression when broadly activated by MGN1703. Based on this hypothesis, the phase 3 IMPALA study has recently started recruitment in several European countries. Patients who achieved an objective response to their 1st-line induction therapy for mCRC are randomized to either continue local standard treatment or start switch maintenance with MGN1703. CEA and activated NKT values at baseline are stratification factors and will be also assessed prospectively.

Conclusions: The exploratory PFS and OS subgroup data from the IMPACT study support the hypothesis that is possible to identify patients more likely to benefit from an immunomodulatory treatment following active induction chemotherapy. This information has been used to design the phase 3 IMPALA study currently recruiting patients.

Citation Format: Werner Scheithauer, Jorge Riera-Knorrenschild, Hans-Georg Kopp, Frank Mayer, Hendrik Kroening, Dieter Nitsche, Jan Kuhlmann, Reinhard Ziebermayr, Johannes Andel, Dirk Arnold, Alfredo Zurlo, Burghardt Wittig, Hans-Joachim Schmoll. Exploratory analyses of the randomized phase 2 IMPACT study: Patients with response to prior induction chemotherapy have improved outcome when treated with the TLR-9 agonist MGN1703. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr B61.

Maintenance therapy with the TLR-9 agonist MGN1703 in the phase II IMPACT study of metastatic colorectal cancer patients: A subgroup with improved overall survival

680

Background: Patients with mCRC and disease control after induction with first-line chemotherapy +/- bevacizumab were included in the double-blind placebo-controlled phase II IMPACT trial, aiming to assess the clinical efficacy, safety, and immunological effects of the immunomodulator MGN1703, a potent TLR9 agonist, given at the dose of 60 mg subcutaneously twice weekly as switch maintenance after first line induction therapy in mCRC. Methods: The trial was prematurely closed after randomization of 59 patients. The final analysis showed a superior effect of MGN1703 compared to placebo with hazard ratios (HR) for the primary endpoint PFS on maintenance of 0.55 (p=0.041) and 0.56 (p=0.070) by local investigator assessment or independent radiological review, respectively. Exploratory PFS analyses of pretreatment characteristics identified patients with normalized CEA, objective response, and the presence of activated NKT cells at the end of induction chemotherapy to benefit the most from maintenance with MGN1703. We analysed the impact of these factors on the secondary endpoint overall survival (OS). Results: At time of final study analysis, OS data were not mature. Only 35% of MGN1703 patients had an event, as opposed to 50% of placebo patients. The HR for OS of whole study population was 0.63 (median 22.6 vs. 15.1 months, p=NS). The subgroup of patients randomized into the study with confirmed RECIST response had a HR of 0.40 (median 24.5 vs. 15.1 months, p=NS), suggesting this may be the population with greater benefit. HR for patients with normalized CEA or with activated NKT cells were 0.69 and 0.43, respectively. Based on this evidence, in the phase III IMPALA study patients with objective response after standard induction therapy are randomized to standard treatment or switch maintenance with MGN1703. CEA and activated NKT cells are stratification factors for the study and will be prospectively assessed. Conclusions: The pretreatment characteristics predictive of a PFS benefit in the IMPACT study seem to retain their value also in exploratory analyses for OS. This information has been used to design the phase III IMPALA study, currently recruiting patients. Clinical trial information: NCT01208194.

Patients' preferences for subcutaneous trastuzumab versus conventional intravenous infusion for the adjuvant treatment of HER2-positive early breast cancer: final analysis of 488 patients in the international, randomized, two-cohort PrefHer study

BACKGROUND

Patients with HER2-positive early breast cancer (EBC) preferred subcutaneous (s.c.) trastuzumab, delivered via single-use injection device (SID), over the intravenous (i.v.) formulation (Cohort 1 of the PrefHer study: NCT01401166). Here, we report patient preference, healthcare professional satisfaction, and safety data pooled from Cohort 1 and also Cohort 2, where s.c. trastuzumab was delivered via hand-held syringe.

PATIENTS AND METHODS

Patients were randomized to receive four adjuvant cycles of 600 mg fixed-dose s.c. trastuzumab followed by four cycles of standard i.v. trastuzumab, or vice versa. The primary endpoint was overall preference proportions for s.c. or i.v., assessed by patient interviews in the evaluable ITT population.

RESULTS

A total of 245 patients were randomized to receive s.c. followed by i.v. and 243 received i.v. followed by s.c. (evaluable ITT populations: 235 and 232 patients, respectively). s.c. was preferred by 415/467 [88.9%; 95% confidence interval (CI) 85.7-91.6; P < 0.0001; two-sided test against null hypothesis of 65% s.c. preference]; 45/467 preferred i.v. (9.6%; 95% CI 7-13); 7/467 indicated no preference (1.5%; 95% CI 1-3). Clinician-reported adverse events occurred in 292/479 (61.0%) and 245/478 (51.3%) patients during the pooled s.c. and i.v. periods, respectively (P < 0.05; 2 × 2 χ(2)); 16 patients (3.3%) in each period experienced grade 3 events; none were grade 4/5.

CONCLUSIONS

PrefHer revealed compelling and consistent patient preferences for s.c. over i.v. trastuzumab, regardless of SID or hand-held syringe delivery. s.c. was well tolerated and safety was consistent with previous reports, including the HannaH study (NCT00950300). No new safety signals were identified compared with the known i.v. profile in EBC. PrefHer and HannaH confirm that s.c. trastuzumab is a validated and preferred option over i.v. for improving patients' care in HER2-positive breast cancer.

CLINICALTRIALSGOV REGISTRATION NUMBER

NCT01401166.

Maintenance treatment with the immunomodulator MGN1703, a Toll-like receptor 9 (TLR9) agonist, in patients with metastatic colorectal carcinoma and disease control after chemotherapy: a randomised, double-blind, placebo-controlled trial

PURPOSE

This phase II study evaluated the synthetic DNA-based immunomodulator and Toll-like receptor 9 agonist MGN1703 as maintenance treatment in metastatic colorectal carcinoma (mCRC).

METHODS

Fifty-nine patients with mCRC and disease control after standard first-line chemotherapy were randomised to MGN1703 60 mg (N = 43) or placebo (N = 16).

RESULTS

The hazard ratio (HR) for the primary endpoint [progression-free survival (PFS) from the start of maintenance] was 0.56 (95 % CI 0.29-1.08; P = 0.07) and 0.55 (95 % CI 0.3-1.0; P = 0.04) by independent and investigator review, respectively. MGN1703 significantly improved PFS measured from the start of induction therapy versus placebo on independent (HR 0.49; 95 % CI 0.26-0.94; P = 0.03) and investigator review (HR 0.50; 95 % CI 0.31-1.02; P = 0.02). Overall survival (OS) data remain immature (HR 95 %; 95 % CI 0.3-1.5; P = 0.29) with 28/43 patients alive after a medium follow-up of >17 months. Retrospective subgroup analysis showed a significant effect of MGN1703 on PFS versus placebo in patients with greater than median tumour size reduction and normalised carcinoembryonic antigen concentrations following induction therapy, and in patients with elevated activated NKT cells ≥3.08 %. Adverse events were mild to moderate and limited to injection-site reactions or linked to general immune system activation.

CONCLUSIONS

MGN1703 maintenance treatment was well tolerated and appears to induce durable and prolonged PFS and disease control in a subgroup of patients with mCRC following induction therapy. Activated NKT cells may be a predictive biomarker for selecting patients likely to benefit more from MGN1703.

Maintenance with the TLR-9 agonist MGN1703 versus placebo in patients with advanced colorectal carcincoma (mCRC): A randomized phase II trial (IMPACT)

3643

Background: Standard induction chemotherapy for mCRC is often discontinued in patients responding to the treatment. MGN1703, a synthetic DNA-based immunomodulator, acts as TLR-9 agonist. This trial has been conducted to assess clinical efficacy, safety, and immunogenicity of MGN1703 as maintenance therapy vs placebo. Methods: The IMPACT trial is an international, multicenter, randomized (2:1) double-blind placebo-controlled phase 2 trial in mCRC patients with disease control (CR, PR, SD) after 4.5 to 6 months of 1st-line induction chemotherapy with FOLFOX/XELOX or FOLFIRI +/- bevacizumab. Results: 59 patients have been randomized (43 MGN1703, 16 placebo). Median PFS from start of maintenance was not different with 2.8 vs 2.7 months, however the HR was 0.56 (CI 95%: 0.29-1.08; p=0.069) in favor of MGN1703, due to a small favorable subgroup with long-term PFS (20% vs 0% at 9 months; p=0.006). Total PFS from beginning of induction chemotherapy including maintenance was significantly improved: HR 0.49 (CI 95%: 0.25-0.94), p=0.029. After a median follow-up of 13 months 66% of patients are still alive (67% vs 62%), therefore survival data are still preliminary (HR 0.79; CI 95%: 0.3-2.1) and will be mature at the meeting. Activation of cellular immune function as indicated by significant increase of CD14+CD169+monocytes was observed in all but one of the MGN1703 treated patients, while absent in all placebo patients. Treatment was well tolerated: 46.5% vs 31.3% of patients (MGN1703 vs placebo) had any drug-related adverse events (AE) and 20.9% vs 18.8% had AE with grade 3 or 4 (including hypertension, ileus, sepsis, sensory polyneuropathy, nausea/vomiting for MGN1703 and pain, popular exanthema for placebo). Conclusions: MGN1703 maintenance seems to prolong PFS in a subgroup of patients with disease control after induction chemotherapy vs placebo, and is associated with relative mild toxicity. This in an early signal in a selected and very limited patient population which supports further investigation. Predictive biomarkers are under evaluation to identify a potential subgroup which might have benefit from this TLR-9 MGN1703 maintenance. Clinical trial information: NCT01208194.

Panitumumab (pmab) in patients (pts) with chemorefractory metastatic colorectal cancer (mCRC): Final analysis from a community-based, observational study (VECTOR) in Germany

550

Background: Pmab monotherapy significantly improves progression-free survival versus best supportive care in pts with chemorefractory KRAS wild-type (WT) mCRC. This study evaluated the efficacy and safety of pmab in routine clinical practice in Germany. Methods: To ensure a representative sample, eligibility criteria were largely unrestricted. Consenting pts were >18 years old, had histologically confirmed KRAS WT mCRC, >4 weeks pmab therapy, failure of fluoropyrimidine-, oxaliplatin- and irinotecan-containing chemotherapy (CTx) regimens, and women of child-bearing age received contraception. Predefined endpoints were overall response rate (ORR; investigator`s assessment) and skin toxicity (NCI Common Terminology Criteria for Adverse Events v3.0). Results: A total of 428 pts were included in the full analysis set. At the start of pmab therapy, median age was 69 (range 22-89) years, 268 pts (63%) were male and 343 (80%) had an ECOG performance status of 0-1. Overall, 400 pts (93%) had undergone prior surgery and 154 (36%) had received ≥1 cycle of adjuvant CTx. Pts had received a median of 3 cycles (range: 1‑12) of prior CTx for mCRC. The most common regimens were FOLFOX/FOLFIRI ±antibody therapy; 65% of regimens were given with palliative, 32% with curative/palliative and 3% with curative intent. The median pmab dose was 6 mg/kg (range 2.4-7.2) q2w for a median of 8 (range 2‑45) cycles, with 143 pts (33%) receiving >10 cycles. The ORR during pmab therapy was 20% (complete response: n=7 [2%]; partial response: n=77 [18%]); disease control (including stable disease) was achieved in 261 pts (61%). Skin reactions occurred in 324 pts (67%) with 52% experiencing a maximum grade ≥2. Most pts had some type of rash (48% acne, 5% desquamation, 4% hand-foot skin reaction, 1% erythema multiforme). Overall, 21% of pts had other toxicities. Three serious adverse drug reactions (infection/fever; thrombosis/embolism; erythema multiforme) and two grade 1 infusion reactions were reported. Conclusions: In this observational study, pmab monotherapy had efficacy at least as good as was seen in the randomised pmab trial and safety was also similar.

Cetuximab plus irinotecan for metastatic colorectal cancer (mCRC): Safety analysis of 800 patients in a randomized phase III trial (EPIC)

3556

Background: EPIC is a randomized phase III study comparing cetuximab plus irinotecan to irinotecan in second-line metastatic, EGFR-expressing mCRC patients (pts) (target N=1,300 pts). Following an independent Data Safety Monitoring Board (DSMB) review of 400 pts., the pooled safety data was presented at ASCO 2005 (#3580). The DSMB has recently reviewed safety data on the first 800 patients. Methods: Patients with EGFR-expressing mCRC who had failed first-line oxaliplatin in combination with a fluoropyrimidine and an ECOG performance status ≤ 2 were randomized to either Arm A (cetuximab 400 mg/m2 followed by 250 mg/ m2 weekly and irinotecan 350 mg/ m2 q 3 weeks) or to Arm B (irinotecan 350 mg/ m2 q 3 weeks). A pooled safety analysis is presented. Results: Eight hundred patients were randomized from May 2003 to March 2005 in Europe, Australia, Asia, and the US: 309 women and 491 men, with a median age of 61 years (range 21–90) and ECOG performance status (PS) of: 0= 53%, 1= 42%, 2= 5%. Seventeen pts received no study therapy and are excluded from the analysis. A total of 3,629 chemotherapy cycles were administered to the 783 pts with a median of 4 cycles per pt (range 1–23). Four (0.5%) subjects experienced severe infusion reactions: 2 grade 3 and 2 grade 4, none were fatal. In this pooled analysis, 59 deaths occurred within 30 days of last study therapy: 45 disease-related, 5 study drug related, 6 due to other causes, and 3 with unknown etiology. A summary table of adverse events (AE’s) is included. Conclusions: The DSMB raised no concerns after reviewing the safety data from 800 pts. In this pooled analysis characteristic toxicities of cetuximab and irinotecan do not appear to be increased, incidences and severities are similar to the earlier safety report based on the initial 400 patients. The study is currently nearing completion of accrual.

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