Abstract 78P
Background
In a real-world (RW) study of patients (pts) with mCRC treated sequentially with R→T or T→R in community clinical practice in the USA, R→T showed longer overall survival (OS) and time to treatment discontinuation (TTD). Liver metastasis and primary tumor sidedness are prognostic factors in mCRC; we conducted an exploratory analysis of outcomes according to these factors and sequencing of R and T.
Methods
The nationwide de-identified Flatiron Health electronic health record-derived database was used to identify pts age ≥18 years at mCRC diagnosis who were treated sequentially with R→T or T→R (Jan 2015 to Nov 2022). Index date was at initiation of the first therapy in a sequence. Clinical outcomes were OS and TTD by primary tumor sidedness (left; right) and metastatic site (liver; non-liver).
Results
Of 818 pts (n=393 R→T; n=425 T→R), most received index therapy in the third line (3L; n=343, 42%) or fourth line (4L; n=194, 24%). Baseline characteristics were similar between cohorts. Overall, 59% of pts had left-sided and 28% had right-sided tumors. Metastatic sites were liver (67%) or non-liver (23%). Median OS was numerically longer with R→T vs T→R in 3L pts with liver metastases or left-sided tumors, and in 4L pts with liver metastases or right-sided tumors (Table). Median TTD was numerically longer with R→T vs T→R in 3L pts with liver (hazard ratio [HR] 0.93; 95% confidence interval [CI] 0.72, 1.22) and non-liver (0.84; 0.51, 1.41) metastases, in 4L pts with liver (0.79; 0.54, 1.15) and non-liver (0.91; 0.47, 1.77) metastases, and in 3L/4L pts with left-sided tumors (3L: HR 0.82; 0.61, 1.11; 4L: HR 0.71; 0.48, 1.05).
Conclusions
This analysis of RW data suggests that pts treated with R→T have a numerical albeit modest improvement in outcomes vs those treated with T→R. This was consistent across treatment line (3L/4L) in pts with liver metastases. Table: 78P
| Median OS ∗ , months HR † (95% CI) | ||||
| 3L | 4L | |||
| R→T (N=167) | T→R (N=176) | R→T (N=87) | T→R (N=107) | |
| Metastatic site | ||||
| Liver | n=121 11.3 | n=124 10.5 | n=60 10.4 | n=66 10.2 |
| 0.93 (0.70, 1.23) | 0.82 (0.55, 1.22) | |||
| Non-liver | n=34 16.1 | n=41 17.2 | n=18 12.4 | n=20 11.0 |
| 0.86 (0.51, 1.47) | 0.99 (0.51, 1.94) | |||
| Primary tumor sidedness | ||||
| Left | n=100 13.3 | n=95 11.5 | n=58 10.4 | n=63 10.2 |
| 0.91 (0.67, 1.24) | 1.02 (0.69, 1.51) | |||
| Right | n=50 10.3 | n=60 11.3 | n=18 16.4 | n=20 9.1 |
| 1.08 (0.70, 1.67) | 0.63 (0.30, 1.29) |
∗Analyzed by Kaplan-Meier method
†Unadjusted
Clinical trial identification
NCT05839951.
Editorial acknowledgement
Medical writing support was provided by Matthew Naylor, PhD, of Luna, OPEN Health Communications, and funded by Bayer HealthCare.
Legal entity responsible for the study
Bayer Healthcare Pharmaceuticals.
Funding
Bayer Healthcare Pharmaceuticals.
Disclosure
D. Ahn: Financial Interests, Personal, Advisory Board: Exelixis, Advanced Accelerator Applicatoins; Financial Interests, Personal, Other, Advisor to discuss treatment landscapes in esophageal cancer: Novartis; Financial Interests, Personal, Stocks/Shares: Natera; Financial Interests, Institutional, Invited Speaker: Bayer, AstraZeneca. T. Bekaii-Saab: Financial Interests, Institutional, Advisory Board: Bayer, Pfizer, Incyte, Ipsen, Seattle Genetics, Genentech, Merck KGA, Merus, Eisai, Servier; Financial Interests, Institutional, Other, DSMB: Merck; Financial Interests, Personal, Advisory Board: AbbVie, Boehringer Ingelheim, Janssen, AstraZeneca, Daiichi Sankyo, Natera, Celularity, Exact Science, Sobi, BeiGene, Xilis, Foundation Medicine, Stemline, Blueprint, Celularity, Caladrius, Glaxo SmithKline, Deciphera, Zai Labs, Illumina, Sanofi; Financial Interests, Personal, Other, DSMB: AstraZeneca, Exelixis, The Valley Hospital, FibroGen; Financial Interests, Personal, Other, DSMC: PanCAN; Financial Interests, Personal, Royalties, WO/2018/183488: Human PD1 peptide vaccines and uses thereof - Licensed to Imugene; Financial Interests, Personal, Royalties, WO/2019/055687: Methods and compositions for the treatment of cancer cachexia – Licensed to Recursion; Financial Interests, Institutional, Research Grant: Agios, Arys, Bayer, Amgen, Ipsen, Clovis, Pfizer, Celgene, Novartis, Arcus, Atreca, Mirati, Merus, Abgenomics, BMS; Financial Interests, Institutional, Invited Speaker: Boston Biomedical, Incyte, Seattle Genetics; Non-Financial Interests, Advisory Role: Imugene, Sun Biopharma. C. Yuan, X. Pan, H. Ostojic, F. Pisa: Financial Interests, Personal, Full or part-time Employment: Bayer.