Abstract 120P
Background
Cetuximab (Cet) plus chemotherapy (CT) has been approved as preferred first-line (1L) treatment for left-sided (LS) metastatic colorectal cancer (mCRC) with wild-type (wt) RAS/BRAF gene. However, it remains uncertain whether Cet is beneficial as maintenance therapy after 1L treatment. This study aimed to investigate the clinical outcomes for maintenance therapy in pts with LS RAS/BRAF wt mCRC who responded to 1L Cet plus CT.
Methods
We performed a retrospective review of pts with LS RAS/BRAF wt mCRC who had disease controlled (CR, PR or SD) after 6 cycles of Cet based induction therapy from JAN 2018 to JUN 2022 at HuNan Cancer Hospital. The 1L regimen consists of Cet plus mFOLFOX6 or FOLFIRI, based on pts selection, followed by maintenance therapy with Cetuximab with or without chemotherapy (cohort A) or chemotherapy alone (cohort B). Death data were obtained from the government's death registry. Kaplan-Meier methods were employed to describe overall survival (OS) and progression-free survival (PFS).
Results
A total of 125 pts were included in this study, with 72 (57.6%) in cohort A and 53 (42.4%) in cohort B. The median age was 58 years (range: 23-76), and 86 (68.8%) were male. The most common site of metastasis was the liver (90 patients, 72.0%). During a median follow-up of 32.6 m, the median OS from the start of 1L therapy was significantly longer in cohort A (46.4 m, 95% CI 40.1-NA) than in cohort B (31.1 m, 95% CI 27.6-38.0; p < 0.0001). Similarly, cohort A (14.2 m, 95% CI 12.4-17.0) had a significantly longer median PFS than cohort B (11.0 m, 95% CI 9.6-11.7; p=0.021). The Cox proportional hazards model, after adjusting for age, sex, primary tumor location, metastatic site, and whether the primary tumor and metastases were resected or not, showed that compared with cohort B, cohort A was associated with a statistically significant longer OS (HR 0.43, 95% CI 0.25-0.73) and a longer PFS, although the difference was not statistically significant (HR 0.70, 95% CI 0.44-1.12).
Conclusions
Maintenance therapy with Cet can significantly improve OS in pts with LS RAS/BRAF wt mCRC and lead to a clinically meaningful improvement in PFS, although the statistical difference was not reached.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
602P - COLUMBUS 7-year update: A randomized, open-label, phase III trial of encorafenib (Enco) + binimetinib (Bini) vs vemurafenib (Vemu) or Enco in patients (Pts) with BRAF V600-mutant melanoma
Presenter: Andrew Haydon
Session: Poster Display
Resources:
Abstract
603P - An individualised postoperative radiological surveillance schedule for IDH-wildtype glioblastoma patients (HK-GBM Registry)
Presenter: Jason Chak Yan Li
Session: Poster Display
Resources:
Abstract
604P - Cabozantinib versus placebo in patients with radioiodine-refractory differentiated thyroid cancer who progressed after prior VEGFR-targeted therapy: Outcomes from COSMIC-311 by BRAF status
Presenter: Marcia Brose
Session: Poster Display
Resources:
Abstract
606P - BRAF and NRAS mutations are associated with poor prognosis in Asians with acral-lentiginous and nodular cutaneous melanoma
Presenter: Sumadi Lukman Anwar
Session: Poster Display
Resources:
Abstract
607P - Single institutional outcomes of radiotherapy and systemic therapy for melanoma brain metastases in Japan
Presenter: Naoya Yamazaki
Session: Poster Display
Resources:
Abstract
608P - The efficacy of immune checkpoint inhibitors and targeted therapy in mucosal melanomas: A systematic review and meta-analysis
Presenter: Andrea Teo
Session: Poster Display
Resources:
Abstract
609P - The association between thyroid function abnormalities and vitiligo induced by pembrolizumab regarding prognosis in patients with advanced melanoma
Presenter: Moez Mobarek
Session: Poster Display
Resources:
Abstract
610P - Analyzing the clinical benefit of the evidence presented at these congresses and utilizing a standardized scale to quantify it will significantly enhance our understanding of the studies showcased, allowing for more objective evaluation and interpretation
Presenter: Charles Jeffrey Tan
Session: Poster Display
Resources:
Abstract
611P - ESMO-magnitude of clinical benefit scale (MCBS) scores for phase III trials of adjuvant and curative therapies at the 2022 ASCO annual meeting (ASCO22)
Presenter: Thi Thao Vi Luong
Session: Poster Display
Resources:
Abstract
612P - Is the juice worth the squeeze? Overall survival gain per unit treatment time as a metric of clinical benefit of systemic treatment in incurable cancers
Presenter: Vodathi Bamunuarachchi
Session: Poster Display
Resources:
Abstract