Clinical Impact of Primary Tumor Location in Metastatic Colorectal Cancer Patients Under Later-Line Regorafenib or Trifluridine/Tipiracil Treatment

Retrospective Correlation between First Drug Treatment Duration and Survival Outcomes in Sequential Treatment with Regorafenib and Trifluridine/Tipiracil in Refractory Metastatic Colorectal Cancer: A Real-World Subgroup Analysis

Background: Patients with refractory metastatic colorectal cancer (mCRC) rarely receive third-line or further treatment. In this context, regorafenib (R) and trifluridine/tipiracil (T) are two important novel therapeutic choices with statistically significant increases in overall survival (OS), progression-free survival (PFS), and disease control, with different toxicity profiles. This study is a subgroup analysis of our larger retrospective study, already published, whose objective was to assess the outcomes of patients when R and T were given sequentially. Patients and Methods: The study involved thirteen Italian cancer centers on a 10-year retrospective observation (2012-2022). In this subgroup analysis, we focused our attention on the correlation between the first drug treatment duration (<3 months, 3 to <6 months and ≥6 months) and survival outcomes in patients who had received the sequence regorafenib-to-trifluridine/tipiracil, or vice versa. Results: The initial study included 866 patients with mCRC who received sequential T/R, or R/T, or T or R alone. This analysis is focused on evaluating the impact of the duration of the first treatment in the sequence on clinical outcomes (OS, PFS) and includes 146 and 116 patients of the T/R and R/T sequences, respectively. Based on the duration of the first drug treatment, subgroups for the T/R sequence included 27 patients (18.4%) who received T for <3 months, 86 (58.9%) treated for 3 to <6 months, and 33 (22.6%) treated for ≥6 months; in the reverse sequence (R as the first drug), subgroups included 18 patients (15.5%) who received their first treatment for <3 months, 62 (53.4%) treated for 3 to <6 months, and 35 (31.0%) treated for ≥6 months. In patients who received their first drug treatment for a period of 3 to <6 months, the R/T sequence had a significantly longer median OS (13.7 vs. 10.8 months, p = 0.0069) and a longer median PFS (10.8 vs. 8.5 months, p = 0.0003) than the T/R group. There were no statistically significant differences between groups with first drug treatment durations of <3 months and ≥6 months. Conclusions: Our analysis seems to suggest that the administration of R for a period of 3 to <6 months before that of T can prolong both OS and PFS, as compared to the opposite sequence.

Treatment Settings and Outcomes with Regorafenib and Trifluridine/Tipiracil at Third-Line Treatment and beyond in Metastatic Colorectal Cancer: A Real-World Multicenter Retrospective Study

BACKGROUND

Patients with refractory mCRC rarely undergo third-line or subsequent treatment. This strategy could negatively impact their survival. In this setting, regorafenib (R) and trifluridine/tipiracil (T) are two key new treatment options with statistically significant improvements in overall survival (OS), progression-free survival (PFS), and disease control with different tolerance profiles. This study aimed to retrospectively evaluate the efficacy and safety profiles of these agents in real-world practice.

MATERIALS AND METHODS

In 2012-2022, 866 patients diagnosed with mCRC who received sequential R and T (T/R, n = 146; R/T, n = 116]) or T (n = 325]) or R (n = 279) only were retrospectively recruited from 13 Italian cancer institutes.

RESULTS

The median OS is significantly longer in the R/T group (15.9 months) than in the T/R group (13.9 months) (p = 0.0194). The R/T sequence had a statistically significant advantage in the mPFS, which was 8.8 months with T/R vs. 11.2 months with R/T (p = 0.0005). We did not find significant differences in outcomes between groups receiving T or R only. A total of 582 grade 3/4 toxicities were recorded. The frequency of grade 3/4 hand-foot skin reactions was higher in the R/T sequence compared to the reverse sequence (37.3% vs. 7.4%) (p = 0.01), while grade 3/4 neutropenia was slightly lower in the R/T group than in the T/R group (66.2% vs. 78.2%) (p = 0.13). Toxicities in the non-sequential groups were similar and in line with previous studies.

CONCLUSIONS

The R/T sequence resulted in a significantly longer OS and PFS and improved disease control compared with the reverse sequence. R and T given not sequentially have similar impacts on survival. More data are needed to define the best sequence and to explore the efficacy of sequential (T/R or R/T) treatment combined with molecular-targeted drugs.

Regorafenib is suitable for advanced colorectal cancer patients who have previously received trifluridine/tipiracil plus bevacizumab

Regorafenib is a standard salvage line therapy used for advanced colorectal cancer (CRC). Recently, trifluridine/tipiracil (TFTD) plus bevacizumab also showed promising efficacy as a salvage line therapy for advanced CRC. However, the efficacy and safety of regorafenib for patients with advanced CRC who have previously received TFTD plus bevacizumab is unclear. We retrospectively collected clinicopathologic data from patients with advanced CRC who received regorafenib after TFTD plus bevacizumab in multiple institutions between April 2017 and June 2020.Thirty-four advanced CRC patients who received regorafenib were analyzed. The median age was 66.5 (range 43-81 years), 11 patients were male, and all had an ECOG performance status(PS) of 0 or 1. Twenty-two patients had left-sided tumors, 18 patients had RAS mutants, and 1 patient had a BRAF V600E mutation. The response rate was 0%, and the disease control rate was 31%. The median progression-free survival was 70 days (95% CI: 56-91), and the overall survival was 233 days (95% CI: 188-324). Treatment was discontinued in 32 patients, and 28 (82%) discontinued treatment due to progressive disease. The major grade 3 and4 toxicities were proteinurea (29%), hypertension (26%), hand-foot syndrome(15%), and platelet decrease (6%). Regorafenib after TFTD plus bevacizumab showed efficacy similar to that of the previous study, and no new adverse events were observed.

Efficacy of third-line anti-EGFR-based treatment versus regorafenib or trifluridine/tipiracil according to primary tumor site in RAS/BRAF wild-type metastatic colorectal cancer patients

Background

Right- (R) and left-sided (L) metastatic colorectal cancer (mCRC) exhibit different clinical and molecular features. Several retrospective analyses showed that survival benefit of anti-EGFR-based therapy is limited to RAS/BRAF wt L-sided mCRC patients. Few data are available about third-line anti-EGFR efficacy according to primary tumor site.

Methods

RAS/BRAF wt patients mCRC treated with third-line anti-EGFR-based therapy versus regorafenib or trifluridine/tipiracil (R/T) were retrospectively collected. The objective of the analysis was to compare treatment efficacy according to tumor site. The primary endpoint was progression-free survival (PFS); secondary endpoints were overall survival (OS), response rate (RR) and toxicity.

Results

A total of 76 RAS/BRAF wt mCRC patients, treated with third-line anti-EGFR-based therapy or R/T, were enrolled. Of those, 19 (25%) patients had a R-sided tumor (9 patients received anti-EGFR treatment and 10 patients R/T) and 57 (75%) patients had a L-sided tumor (30 patients received anti-EGFR treatment and 27 patients R/T). A significant PFS [7.2 vs 3.6 months, HR 0.43 (95% CI 0.2-0.76), p= 0.004] and OS benefit [14.9 vs 10.9 months, HR 0.52 (95% CI 0.28-0.98), p= 0.045] in favor of anti-EGFR therapy vs R/T was observed in the L-sided tumor group. No difference in PFS and OS was observed in the R-sided tumor group. A significant interaction according to primary tumor site and third-line regimen was observed for PFS (p= 0.05). RR was significantly higher in L-sided patients treated with anti-EGFR vs R/T (43% vs. 0%; p <0.0001), no difference was observed in R-sided patients. At the multivariate analysis, third-line regimen was independently associated with PFS in L-sided patients.

Conclusions

Our results demonstrated a different benefit from third-line anti-EGFR-based therapy according to primary tumor site, confirming the role of L-sided tumor in predicting benefit from third-line anti-EGFR vs R/T. At the same time, no difference was observed in R-sided tumor.

Biomarkers of Trifluridine-Tipiracil Efficacy

Trifluridine/tipiracil (TAS-102) is a newer generation chemotherapy that has been approved for the later-line treatment of metastatic colorectal and gastric/gastroesophageal adenocarcinomas. The oral drug provides a modest benefit of prolongation of survival over placebo in pretreated patients with these cancers with acceptable toxicity. Studies have shown rare objective responses (2-4%), and the disease control rates were 44% in both colorectal and gastric cancer randomized trials. Thus, the majority of patients progress through treatment and are burdened by toxicities. To better characterize the sub-group of patients with a higher probability of benefit from trifluridine/tipiracil, predictive biomarkers have been sought using data from randomized trials as well as from non-randomized trials and real-world series. Biomarkers examined include clinical characteristics of the patients, laboratory tests, and tumor derived biomarkers. These studies show that early neutropenia on treatment, and ratios of leukocyte subsets, are potential biomarkers able to predict trifluridine/tipiracil benefit. Combinations of laboratory values and clinical characteristics and proteins involved in trifluridine transport and activation have been examined with initial positive results.