Utilization of TAS-102 (TAS) or regorefenib (Rego) among commercially insured refractory metastatic colorectal cancer (R-mCRC) patients.

Abstract

e23121 Background: R-mCRC is the time period after use of fluoropyrimidine, oxaliplatin, and irinotecan and usually in conjunction with biological therapies. Several agents are efficacious during R-mCRC with high level evidence for survival improvement. We describe access and utilization of therapeutics in this state using claims data. Methods: This is a retrospective cohort study using the Optum’s de-identified Clinformatics® Data Mart Database (2013-2020). We identified patients (pts) with mCRC after 2014; the metastasis date was set as the index date. Pts were required to have a continuous enrollment for 6 months pre- and 18 months post-index to ensure they were potentially in the refractory setting. Eligible pts were required to have utilization of standard therapies after diagnosis of metastatic disease. Those who switched from FOLFOX to FOLFIRI or vice versa were classified as refractory. The use of either TAS or Rego was identified during the entire follow-up period. Baseline characteristics were compared between patients who received TAS or Rego and those who did not using Chi-Squared test/T-test. We conducted multivariate logistic regressions to evaluate the factors associated with patients’ access to TAS or Rego. Results: 6,233 pts with mCRC identified, 53.7% male, and 70.4% white. FOLFOX was the dominant treatment in the 1L setting (60.1%). 9.7% received either TAS or Rego, with 4.8% taking Rego first and 4.9% receiving TAS first. Recipients of TAS or Rego were younger (mean age of 62.8 vs. 66.5, p < 0.001) and had fewer comorbidities (e.g. myocardial infarction was associated with reduced probability of receiving either TAS or Rego (p < 0.05)). More were enrolled in preferred provider organization in pts using these agents (45% vs. 37.5%, p < 0.001). In the multivariate analysis, Asian pts had a higher likelihood of using late-line therapies (OR = 1.53, p < 0.05). Among 707 pts who switched from FOLFOX to FOLFIRI or vice versa (R-mCRC), 29.8% received late-line therapy (15.7% TAS followed by Rego). The trends were similar among these patients. The TAS or Rego recipients were younger than the non-recipients (mean age of 60.6 vs. 63.8, p < 0.001), had fewer comorbidities, and enrolled in preferred provider organization (47.5% vs. 38.5%, p < 0.05). Conclusions: While front line therapy for mCRC is relatively homogenous, there is significant heterogeneity in transitioning and receiving later lines of therapy. This claims level analysis highlights the disparities in access to later lines of therapy. Further analyses for characterization of the patterns of care and disparities are underway.