Phase I/II study of 24-hour infusion of irinotecan combined with oral UFT for metastatic colorectal cancer

Would the Recommended Dose Have Been Different Using Novel Dose-Finding Designs? Comparing Dose-Finding Designs in Published Trials

Simulation studies have shown that novel designs such as the continual reassessment method and the Bayesian optimal interval (BOIN) design outperform the 3 + 3 design by recommending the maximum tolerated dose (MTD) more often, using less patients, and allotting more patients to the MTD. However, it is not clear whether these novel designs would have yielded different results in the context of real-world dose-finding trials. This is a commonly mentioned reason for the continuous use of 3 + 3 designs for oncology trials, with investigators considering simulation studies not sufficiently convincing to warrant the additional design complexity of novel designs.

METHODS

We randomly sampled 60 published dose-finding trials to obtain 22 that used the 3 + 3 design, identified an MTD, published toxicity data, and had more than two dose levels. We compared the published MTD with the estimated MTD using the continual reassessment method and BOIN using target toxicity rates of 25% and 30% and toxicity data from the trial. Moreover, we compared patient allocation and sample size assuming that these novel designs had been implemented.

RESULTS

Model-based designs chose dose levels higher than the published MTD in about 40% of the trials, with estimated and observed toxicity rates closer to the target toxicity rates of 25% and 30%. They also assigned less patients to suboptimal doses and permitted faster dose escalation.

CONCLUSION

This study using published dose-finding trials shows that novel designs would recommend different MTDs and confirms the advantages of these designs compared with the 3 + 3 design, which were demonstrated by simulation studies.

Oral S-1 with 24-h Infusion of Irinotecan plus Bevacizumab versus FOLFIRI plus Bevacizumab as First-Line Chemotherapy for Metastatic Colorectal Cancer: An Open-Label Randomized Phase II Trial

BACKGROUND

FOLFIRI plus bevacizumab have been widely used as first-line treatment for metastatic colorectal cancer (mCRC). Pharmacokinetics and pharmacodynamics suggested a low dose of irinotecan given as a long-term infusion is expected to enhance antitumor activity. We conducted a randomized phase II study to compare oral S-1 with a 24-h infusion of irinotecan plus bevacizumab versus FOLFIRI plus bevacizumab.

METHODS

The subjects comprised 120 chemotherapy-naïve patients with mCRC. The study group received a 24-h infusion of irinotecan at a dose of 125 mg/m2 on days 1 and 15, combined with oral S-1 80 mg/m2 on days 1-14 (24h-SIRI/B). The FOLFIRI/B group received irinotecan at a dose of 150 mg/m2, 5-fluorouracil given at a dose of 400 mg/m2 as a bolus injection and at a dose of 2,400 mg/m2 as a 46-h infusion, and 200 mg/m2 leucovorin on days 1 and 15. Bevacizumab was given at a dose of 5.0 mg/kg on days 1 and 15 in both groups. Treatment was repeated every 4 weeks. The primary endpoint was 1-year progression-free survival (PFS). Secondary endpoints were PFS, response rates (RR), overall survival (OS), and adverse events (AEs).

RESULTS

From December 2013 through January 2018, 120 patients were randomly assigned, 61 patients to the 24h-SIRI/B and 59 patients to the FOLFIRI/B. The median follow-up period was 22.8 months. The 1-year PFS rate was 43.14% in the 24h-SIRI/B arm and 19.15% in the FOLFIRI/B arm (HR = 0.312 [95%CI 0.13-0.78], p = 0.01). The median PFS was 10.2 months (95%CI 8.8-14.3) and 10.0 months (95%CI 7.4-11.0), and the median OS was 29.7 months (95%CI 22.9-43.9) and 28.8 months (95%CI 18.4-ND), respectively (p = 0.3758, p = 0.8234). The overall RR was 86.3 and 61.7%, respectively (p = 0.0053). AEs were similar.

CONCLUSIONS

Our results show that the 24h-SIRI/B regimen is an effective and reasonably well-tolerated regimen for the first-line treatment of mCRC.

A Phase II Trial of Combined Chemotherapy with Oral S-1 and 24-Hour Infusions of Irinotecan plus Bevacizumab in Patients with Metastatic Colorectal Cancer

OBJECTIVES

Protracted low-dose infusion of irinotecan has been suggested to enhance antitumor activity. A phase II study was conducted to evaluate the safety and efficacy of oral S-1 combined with 24-hour infusion of irinotecan and intravenous bevacizumab for metastatic colorectal cancer (MCRC).

METHODS

The subjects were 79 patients with MCRC; 57 were chemotherapy naïve. Irinotecan (125 mg/m(2)) was administered as a 24-hour infusion on days 1 and 15, S-1 (80 mg/m(2)) was administered orally on days 1-14, and bevacizumab (5.0 mg/kg) was given on days 1 and 15. The treatment was repeated every 4 weeks.

RESULTS

Median follow-up was 20.0 months, and the mean number of cycles was 7. The overall response rate was 79.7% (95% CI, 69.2-88.0), 86.0% (95% CI, 74.2-93.7) for first-line and 63.6% (95% CI, 40.7-82.8) for second-line treatment. The median progression-free survival was 16.4 months (95% CI, 13.9-21.0) for first-line and 9.4 months (95% CI, 4.9-16.5) for second-line treatment. The median overall survival was not reached. Grade 3-4 toxicities were neutropenia (43%), leukopenia (20.3%), anorexia (19.0%), and diarrhea (10.1%). Toxicity was tolerable.

CONCLUSIONS

Combination chemotherapy with oral S-1 and biweekly 24-hour infusions of irinotecan plus bevacizumab appears to be highly active and well tolerated both as first-line and second-line chemotherapy for MCRC.

Phase I study of irinotecan by 24-h intravenous infusion in combination with 5-fluorouracil in metastatic colorectal cancer

BACKGROUND

This study was intended to ascertain the feasibility of a combination therapy with irinotecan by 24-h intravenous infusion (24-h CPT-11) and 5-fluorouracil (5-FU) for patients with metastatic colorectal cancer, to estimate the dose-limiting toxicity (DLT) and the maximum tolerated dose (MTD), to determine the recommended dose (RD) for the Phase II study, and to evaluate the efficacy of the combination therapy.

METHODS

The dosage regimen was as follows: CPT-11 was given by 24-h CPT-11 on day 1, followed by 24-h intravenous infusion of 5-FU on day 2. This regimen was repeated every 2 weeks. The dose of CPT-11 was escalated in five steps from 50 to 75, 100, 125, or 150 mg/m(2) (levels 1-5), whereas the dose of 5-FU was fixed at 800 mg/m(2).

RESULTS

Twenty-six patients were recruited for this study, and 25 of the 26 patients were eligible for the assessment. The DLTs of 24-h CPT-11/5-FU therapy included grade 3 diarrhea in 1 patient treated at level 1, and grade 3 neutropenia in 1 patient and grade 4 neutropenia in 1 patient at level 4. In level 5, in 3 cases the next administration could not be done for 22 days or more as a consequence of anorexia. Thus, the level 5 was made a MTD and the level 4 was made a RD. The main side effects of grade 3 or higher, although nausea/vomiting occurred, were mild and tolerable in severity overall. The overall response rate was 24.0% (6PR/25).

CONCLUSION

This study suggests that 24-h CPT-11/5-FU therapy is feasible and effective for treatment of metastatic colorectal cancer.