Colorectal cancer

Real-world characteristics and outcomes of patients with third-line or later metastatic colorectal cancer: Magnetic-101 study results

Summary

Colorectal cancer (CRC) is the 3rd most common cancer and 2nd cause of cancer death in the US. Chemotherapy is the mainstay for patients (pts) with metastatic CRC (mCRC). Pts have limited treatment options available in 3rd and later lines (3L+).

Methods

Magnetic-101 was an observational, retrospective cohort study of pts with mCRC in the US that utilized ConcertAI Patient360™ database (Jan 2017–Oct 2024). Adult pts with unresectable mCRC who received ≥3 lines of therapy (LoT) were included; pts with multiple primary cancers or treated in clinical trials were excluded. The study evaluated pt demographics, clinical characteristics, and treatment regimens in 3L+ settings. In the microsatellite stable (MSS) subgroup, defined based on receipt of immunotherapies, real-world (RW) clinical outcomes by LoT, including time to next treatment or death (rwTTNT-D), overall survival (rwOS), and progression-free survival (rwPFS) were explored via Kaplan–Meier methodology.

Results

Overall, 524 pts met eligibility criteria and received 3L+ treatment; 46% were female, 71% White, and 80% were treated in community settings. Median (range) age at initial diagnosis was 61 years (24–78). At 3L initiation, 70% had an ECOG score of 0 or 1. Among 524 3L+ pts, 229 (44%) received 4L and 140 (27%) received 5L+ (including 99 who received 5L). Trifluridine/tipiracil-based treatment was the most commonly used regimen in 3L pts [129 (25%)] and 4L [88 (38%)], and both trifluridine/tipiracil- and regorafenib-based in 5L pts [24 (24%) for each]. In the MSS subgroup (n=473), clinical outcomes were poor (Table); the survival probability of rwOS and rwPFS for 3L, 4L, and 5L+ pts at 4 months was 76% and 35%, 76% and 34%, and 69% and 32%, respectively, and at 6 months was 63% and 20%, 59% and 17%, and 49% and 16%, respectively.

Conclusions

This RW data suggests poor outcomes for pts with 3L+ mCRC on current therapies and an urgent need for novel treatment.