FOLFIRI and regorafenib combination therapy with dose escalation of irinotecan as fourth-line treatment for patients with metastatic colon cancer according to UGT1A1 genotyping

Case report: Efficacy and safety of regorafenib plus fluorouracil combination therapy in the treatment of refractory metastatic colorectal cancer

Background

More than half of patients with colorectal cancer (CRC) present with metastatic disease or develop recurrent disease on first-line and second-line options. Treatment beyond the second line remains an area of unmet need for patients with progressive or recurrent disease.

Methods

We retrospectively reviewed data of adult (>18 years old) patients with mCRC who received regorafenib + 5FU combination therapy at Houston Methodist Hospital with outcomes of interest including response rate, discontinuation due to side effects, and overall survival.

Results

Seven patients received regorafenib + 5FU combination therapy for mCRC after receiving at least two other lines of therapy (including at least one fluorouracil-based therapy). Four patients (57%) achieved disease control in 7-12 weeks after therapy initiation while three patients developed recurrent disease. In patients who achieved disease control, no new adverse events were reported among patients with this combination.

Conclusion

Regorafenib and Fluorouracil combination could be considered an option beyond the second line for patients with treatment-refractory metastatic colorectal cancer. Further studies, including a prospective trial, are needed to investigate the efficacy and safety of regorafenib plus 5FU therapy compared to other limited available therapies.

Oncologic Outcomes in Metastatic Colorectal Cancer with Regorafenib with FOLFIRI as a Third- or Fourth-Line Setting

BACKGROUND

To evaluate the efficacy and toxicities of regorafenib plus irinotecan, dose-escalated on the basis of uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) genotyping, in previously heavily treated metastatic colorectal cancer (mCRC) and the prognostic values of EGFR expression, KRAS mutations, and tumor sidedness.

METHODS

Forty-one patients with mCRC with disease progression after treatment with fluoropyrimidines, oxaliplatin, irinotecan, anti-VEGF, and anti-EGFR MoAbs were subjected to UGT1A1 genotyping and received regorafenib combined with FOLFIRI with dose-escalated irinotecan.

RESULTS

The median follow-up period was 10.0 months (1.3-23.5 months). The overall disease control rate was 58.5%, whereas the median progression-free survival (PFS) and overall survival (OS) were 6.0 months and 12.0 months, respectively. KRAS mutations were significantly associated with positive EGFR expression (P = .026). KRAS mutations significantly correlated with a shorter OS than KRAS wild-type (6.0 vs. 14.4 months, P = .014) but had no significant association with PFS. Positive EGFR expression had an inverse correlation with PFS (2.5 vs. 14.0 months, P = .039) and OS (9.6 vs. 19.7 months, P = .044). Moreover, left-sided tumors associated with superior PFS (2.0 vs. 7.0 months, P < .0001) and OS (4.0 vs. 13.0 months, P < .0001), and tumor sidedness was an independent prognostic factor by the multivariate analysis.

CONCLUSION

Regorafenib and FOLFIRI concomitant therapy with dose-escalated irinotecan seemed to be potentially practicable with satisfactory oncological results. KRAS mutations and EGFR expression might be predictors of poor oncological outcomes; however, left-sided mCRCs would be more beneficial for concomitant regorafenib and FOLFIRI therapy.

Combination chemotherapy with Regorafenib in metastatic colorectal cancer treatment: A single center, retrospective study

BACKGROUND

Regorafenib has been demonstrated as effective in refractory metastatic colorectal cancer. Combination use with chemotherapy has not been reported. We examined the efficacy and safety of adding chemotherapy to Regorafenib for the treatment of metastatic colorectal cancer(mCRC) patients.

METHODS

We recruited mCRC patients at our institute who received either regorafenib monotherapy or regorafenib in combination with other chemotherapies. All patients had received chemo and target therapies and presented with disease progression before regorafenib treatment. The primary end point was overall survival.

FINDINGS

Between September1, 2015 and May 31, 2017, 100 mCRC patients at our institute received regorafenib treatment. 39 patients were excluded due to poor performance, lack of timely treatment, or inadequate clinical data. A total of 34 patients received regorafenib combined with other chemotherapies, and 27 patients received regorafenib alone. Median follow up time was 10.4 and 6.1 months, respectively. The primary end point of median OS was higher in the combination group than in the single use group (20.9m vs 10.3m, p = 0.015). The most frequent adverse events were hand-foot skin reactions(16[47.1%]vs 12[44.4%]), fatigue(6[17.6%] vs 7[25.9%]), gastrointestinal discomfort (7[20.6%] vs 6[22.2%]), neutropenia (4[11.8%] vs 1[3.7%]), diarrhea(4[11.8%] vs 1[3.7%]), and mucositis(5[14.7%] vs 1[3.7%]).

CONCLUSION

The present study showed the efficacy and side effects of regorafenib combination treatment. Superiority in median OS and median PFS was noted in the combination group. The sampling difference between the study and observation groups effects justifies the comparison. Further clinical evidence of combination therapy efficacy is pending future studies.

Regorafenib Plus FOLFIRI With Irinotecan Dose Escalated According to Uridine Diphosphate Glucuronosyltransferase 1A1 Genotyping in Patients With Metastatic Colorectal Cancer

We analyzed the results of previously treated patients with metastatic colorectal cancer (mCRC) who received regorafenib plus FOLFIRI with the irinotecan dose escalation on the basis of uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) genotyping. Thirteen patients with previously treated mCRC were subjected to UGT1A1 genotyping between October 2013 and June 2015 and were administered regorafenib plus FOLFIRI with irinotecan dose escalation. Patients with UGT1A1*1/*1 and *1/*28 genotypes were administered 180 mg/m2 of irinotecan, whereas those with the UGT1A1*28/*28 genotype were administered 120 mg/m2 of irinotecan. For all patients, the irinotecan dose was increased by 30 mg/m2 every two cycles until grade ≥3 adverse events or severe adverse events developed, following which the dose was reverted to and maintained at the previously tolerated level. The oral regorafenib dose was adjusted to 120 mg/day daily. The median follow-up period was 10.0 months (1.0-21.0 months). The disease control rate was 69.2%, whereas the median progression-free survival and overall survival were 9.5 and 13.0 months, respectively. Our findings indicate that regorafenib plus FOLFIRI with irinotecan dose escalation based on UGT1A1 genotyping in previously treated patients with mCRC and with UGT1A1*1/*1 and UGT1A1*1/*28 genotypes is clinically effective and yields improved oncological outcomes.

Regorafenib with a fluoropyrimidine for metastatic colorectal cancer after progression on multiple 5-FU-containing combination therapies and regorafenib monotherapy

We present 2 patients with metastatic colorectal cancer who had progressed despite treatment with first-line FOLFOX and second-line FOLFIRI combination chemotherapy regimens. After failing these fluoropyrimidine-based regimens, both patients received additional cytotoxic and targeted therapies with eventual disease progression. These therapies included capecitabine plus dabrafenib and trametinib, regorafenib monotherapy, and regorafenib with panitumumab. After exhausting available options, both patients were offered regorafenib with either 5-fluorouracil (5-FU) or capecitabine. These therapies are individually approved for the treatment of colorectal cancer but have not yet been studied in combination. This regimen produced stable disease in both patients with acceptable toxicity. One patient continued therapy for 17 months. Although these patients previously progressed during treatment with regorafenib, capecitabine or 5-FU, the combination had some activity in both cases of refractory metastatic colorectal cancer and may be considered in the palliative setting. In bedside-to-bench cell culture experiments performed after the clinical observations, we observed sensitivity of human colorectal cancer cell lines (N = 4) to single agent regorafenib or 5-FU and evidence of synergy with the combination therapy. Synergistic effects were noted in colorectal cancer cells with KRAS mutation, BRAF mutation, and p53 mutation, as well as mismatch repair deficient cells. Regorafenib suppressed Mcl-1 and Bcl-XL in treated cancer cells that may have contributed to the anticancer efficacy including in combination with 5-FU. The safety and efficacy of regorafenib with 5-FU or capecitabine in combination should be further investigated as a therapy for patients with refractory metastatic colorectal cancer, including individuals who had progressed on regorafenib monotherapy.