Abstract 2589
Background
Cetuximab (CET) in combination with chemotherapy is approved for a once-weekly (q1w) schedule at an initial dose of 400 mg/m², followed by weekly doses of 250 mg/m², in patients with RAS wild-type (wt) metastatic colorectal cancer (mCRC). However in clinical practice, an off-label schedule of CET 500 mg/m2 every-2-weeks (q2w) is frequently used. This pooled analysis of patient-level data aimed to test the noninferiority of the q2w vs q1w schedule on overall survival (OS).
Methods
All post-authorization studies with patient-level data available to marketing authorization holder at time of study design, in patients with confirmed RAS wt mCRC who received a first-line treatment with CET q1w or q2w in combination with chemotherapy from 2007 to 2018 were included: 2 non-interventional cohort studies (NIS) (EREBUS, ERBITAG) and 3 clinical trials (CEBIFOX, CECOG/CORE 1.2.002, APEC). Patients were categorized into q1w or q2w groups according to the CET schedule planned at initiation. OS was calculated from first CET infusion until all-cause death and censored at the last date patients were known to be alive. The noninferiority of the q2w vs q1w schedule was tested with a hazard ratio (HR) margin of 1.25 using a Cox proportional hazards regression model. Differences in baseline characteristics were accounted for with inverse probability of treatment weighting (IPTW) based on a propensity score.
Results
763 (91% from NIS) and 554 (51% from NIS) patients were included in the q1w and q2w groups, respectively. Median (Q1-Q3) age in years was 66 (57-73) for q1w and 60 (53-69) for q2w. Liver-limited disease concerned 42.6% of patients for q1w and 37.9% for q2w. A baseline ECOG Performance Status of 0-1 was reported in 81.8% of q1w and 90.6% of q2w patients. FOLFIRI was most frequently used in combination with q1w (49.4%) and FOLFOX with q2w (59.2%). IPTW-adjusted HRs for OS were in favor of q2w: 0.83 (95% CI, 0.71-0.96) and 0.73 (95% CI, 0.61-0.88) when restricted to NIS. Other efficacy and safety results will be presented in the future.
Conclusions
This pooled analysis confirmed the noninferiority of CET q2w vs q1w. This result suggests an improved OS with the q2w schedule.
Clinical trial identification
Editorial acknowledgement
ClinicalThinking, Inc, Hamilton, NJ, USA, funded by Merck Healthcare KGaA, Darmstadt, Germany.
Legal entity responsible for the study
Merck Healthcare KGaA.
Funding
Merck Healthcare KGaA.
Disclosure
S. Kasper: Honoraria (self), Honoraria (institution), Advisory / Consultancy, Research grant / Funding (self), Research grant / Funding (institution), Travel / Accommodation / Expenses: Merck; Honoraria (self), Honoraria (institution), Advisory / Consultancy, Travel / Accommodation / Expenses: Amgen; Honoraria (self), Honoraria (institution), Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Sanofi; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Aventis; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Servier; Honoraria (self), Honoraria (institution), Advisory / Consultancy, Research grant / Funding (self), Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly. F. Overkamp: Honoraria (self), Advisory / Consultancy: Amgen; Honoraria (self), Advisory / Consultancy: AstraZeneca; Honoraria (self), Advisory / Consultancy: Bayer; Honoraria (self), Advisory / Consultancy: BMS; Honoraria (self), Advisory / Consultancy: Boehringer Ingelheim; Honoraria (self), Advisory / Consultancy: Chugai; Honoraria (self), Advisory / Consultancy: Celgene; Honoraria (self), Advisory / Consultancy: Cellex; Honoraria (self), Advisory / Consultancy: Eisai; Honoraria (self), Advisory / Consultancy: Gilead; Honoraria (self), Advisory / Consultancy: Hexal; Honoraria (self), Advisory / Consultancy: Ipsen; Honoraria (self), Advisory / Consultancy: Janssen-Cilag; Honoraria (self), Advisory / Consultancy: Merck; Honoraria (self), Advisory / Consultancy: MSD; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy: Novonordisc; Honoraria (self), Advisory / Consultancy: Riemser; Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy: Servier. C. Foch: Full / Part-time employment: Merck Healthcare KGaA. F. Lamy: Full / Part-time employment: Merck Healthcare KGaA. R. Esser: Full / Part-time employment: Merck Healthcare KGaA. D. Messinger: Full / Part-time employment, Prometris provides statistical services for Merck Healthcare KGaA: Merck Healthcare KGaA. V. Rothe: Full / Part-time employment, Prometris provides statistical services for Merck Healthcare KGaA: Merck Healthcare KGaA. W. Chen: Full / Part-time employment: Merck Serono. T. Brodowicz: Honoraria (self): Roche; Honoraria (self), Advisory / Consultancy: Amgen; Honoraria (self), Advisory / Consultancy: Bayer; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy: PharmaMar; Honoraria (self), Advisory / Consultancy: Eisai; Honoraria (self), Advisory / Consultancy: Lilly. C.C. Zielinski: Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy: BMS; Honoraria (self), Advisory / Consultancy: MSD; Honoraria (self), Advisory / Consultancy: Imugene; Honoraria (self), Advisory / Consultancy: ARIAD; Honoraria (self), Advisory / Consultancy: Pfizer; Honoraria (self), Advisory / Consultancy: Merrimack; Honoraria (self), Advisory / Consultancy: Merck Healthcare KGaA; Honoraria (self), Advisory / Consultancy: FibroGen; Honoraria (self), Advisory / Consultancy: AstraZeneca; Honoraria (self), Advisory / Consultancy: Tesaro; Honoraria (self), Advisory / Consultancy: Gilead; Honoraria (self), Advisory / Consultancy: Servier; Honoraria (self), Advisory / Consultancy: Shire; Honoraria (self), Advisory / Consultancy: Lilly; Honoraria (self), Advisory / Consultancy: Athenex. All other authors have declared no conflicts of interest.
Resources from the same session
3911 - Defining a SUV decrease cut-off in PET/CT response monitoring after one cycle of preoperative breast cancer chemotherapy
Presenter: Marcin Kubeczko
Session: Poster Display session 2
Resources:
Abstract
1849 - Effect of thioredoxin 1 quantity detection to complement the mammography in breast cancer diagnosis
Presenter: Younju Lee
Session: Poster Display session 2
Resources:
Abstract
2221 - Identification of ultralow risk breast cancer patients (probable overdiagnosis)
Presenter: Salvador Gamez Casado
Session: Poster Display session 2
Resources:
Abstract
5291 - Prevalence of Vitamin D3 deficiency among women with early breast cancer receiving chemotherapy in an oncology dayward.
Presenter: Warner Finstad
Session: Poster Display session 2
Resources:
Abstract
4247 - Changes in ER pathway activity score during neoadjuvant letrozole to assess therapy response and predict disease free survival (DFS) in ER positive breast cancer patients
Presenter: Arran Turnbull
Session: Poster Display session 2
Resources:
Abstract
568 - Second primary malignancies in patients with breast cancer.
Presenter: Carlos Erasun Lecuona
Session: Poster Display session 2
Resources:
Abstract
1428 - Phase II randomized trial of neoadjuvant trastuzumab and pertuzumab (TP) with either palbociclib + letrozole (Pal+L) or paclitaxel (Pac) for elderly patients with estrogen receptor & HER2 positive (ER+/HER2+) Breast Cancer (BC) (International Breast Cancer Study Group IBCSG 55-17, TOUCH)
Presenter: Laura Biganzoli
Session: Poster Display session 2
Resources:
Abstract
1479 - Neoadjuvant HER2-targeted therapy with or without immunotherapy with pembrolizumab (neoHIP): an open label randomized phase 2 trial
Presenter: Heather McArthur
Session: Poster Display session 2
Resources:
Abstract
1481 - A randomized phase 2 study of peri-operative ipilimumab, nivolumab and cryoablation versus standard care in women with residual, early stage/resectable, triple negative breast cancer after standard-of-care neoadjuvant chemotherapy
Presenter: Heather McArthur
Session: Poster Display session 2
Resources:
Abstract
4334 - ALEXANDRA/IMpassion030: A phase 3 study of standard adjuvant chemotherapy with or without atezolizumab in early stage triple negative breast cancer.
Presenter: Michail Ignatiadis
Session: Poster Display session 2
Resources:
Abstract