A phase I study of combination therapy with S-1 and irinotecan (CPT-11) in patients with advanced colorectal cancer

REDOMA: Bayesian random-effects dose-optimization meta-analysis using spike-and-slab priors

The rise of cutting-edge precision cancer treatments has led to a growing significance of the optimal biological dose (OBD) in modern oncology trials. These trials now prioritize the consideration of both toxicity and efficacy simultaneously when determining the most desirable dosage for treatment. Traditional approaches in early-phase oncology trials have conventionally relied on the assumption of a monotone relationship between treatment efficacy and dosage. However, this assumption may not hold valid for novel oncology therapies. In reality, the dose-efficacy curve of such treatments may reach a plateau at a specific dose, posing challenges for conventional methods in accurately identifying the OBD. Furthermore, achieving reliable identification of the OBD is typically not possible based on a single small-sample trial. With data from multiple phase I and phase I/II trials, we propose a novel Bayesian random-effects dose-optimization meta-analysis (REDOMA) approach to identify the OBD by synthesizing toxicity and efficacy data from each trial. The REDOMA method can address trials with heterogeneous characteristics. We adopt a curve-free approach based on a Gamma process prior to model the average dose-toxicity relationship. In addition, we utilize a Bayesian model selection framework that uses the spike-and-slab prior as an automatic variable selection technique to eliminate monotonic constraints on the dose-efficacy curve. The good performance of the REDOMA method is confirmed by extensive simulation studies.

A straightforward meta-analysis approach for oncology phase I dose-finding studies

Phase I early-phase clinical studies aim at investigating the safety and the underlying dose-toxicity relationship of a drug or combination. While little may still be known about the compound's properties, it is crucial to consider quantitative information available from any studies that may have been conducted previously on the same drug. A meta-analytic approach has the advantages of being able to properly account for between-study heterogeneity, and it may be readily extended to prediction or shrinkage applications. Here we propose a simple and robust two-stage approach for the estimation of maximum tolerated dose(s) utilizing penalized logistic regression and Bayesian random-effects meta-analysis methodology. Implementation is facilitated using standard R packages. The properties of the proposed methods are investigated in Monte Carlo simulations. The investigations are motivated and illustrated by two examples from oncology.

Oral maintenance therapy using apatinib combined with S-1/capecitabine for esophageal squamous cell carcinoma with residual disease after definitive chemoradiotherapy

Background: A substantial number of patients with esophageal squamous cell carcinoma (ESCC) do not achieve complete remission after definitive concurrent chemoradiotherapy (dCRT). We performed this retrospective study to evaluate the efficacy and safety of apatinib combined with S-1/capecitabine as the oral maintenance therapy for these patients.

Methods: Thirty-nine ESCC patients with residual disease after dCRT were included. Patients were treated with apatinib combined with S-1 /capecitabine after dCRT. Efficacy, toxicity, and survival were analyzed.

Results: Of the 39 patients, 5 (12.8%) achieved a partial response and 29 (74.4%) achieved stable disease, yielding a disease control rate of 87.2%. The median progression-free survival (PFS) and overall survival (OS) were 27.5 (95%CI: 14.9 - 40.1) and 38.1 (95%CI: 31.3 - 44.8) months. Most frequent adverse events were of grade 1 to 2. Multivariate analysis revealed the occurrence of any adverse events (HR = 0.274, 95%[CI] = 0.119 - 0.630) correlated to better PFS and occurrence of proteinuria (HR = 0.108, 95%[CI] = 0.025 - 0.456) predicted better OS.

Conclusion: The oral combination therapy consisting of apatinib and S-1/capecitabine showed a tolerable toxicity profile and achieved satisfactory disease control in ESCC patients with residual disease after dCRT.

Current Development of Anti-Cancer Drug S-1

S-1 is a novel oral fluoropyrimidine derivative, widely used for treating gastric, pancreatic, lung, head, neck and breast carcinomas. It is designed to enhance the clinical utility of an oral fluoropyrimidine and is associated with low gastrointestinal toxicity. S-1 consists of three pharmacological agents (at a molar ratio of 1:0.4:1)-Tegafur (FT), a prodrug of 5-Fluorouracil (5-FU), 5-Chloro-2-4-Dihydroxypyridine (CDHP), which inhibits the activity of Dihydropyrimidine Dehydrogenase (DPD) and Oxonic Acid (Oxo), which reduces Gastrointestinal (GI) toxicity of 5-FU. The present article reviews the current development of clinical study of S-1.

A phase I study of S-1 and irinotecan combination therapy in previously treated advanced non-small cell lung cancer patients

BACKGROUND

This phase I study was conducted to evaluate the feasibility and to determine the recommended doses of the combination therapy of S-1 and irinotecan (CPT-11) in patients with advanced non-small cell lung cancer (NSCLC) as second-line treatment.

METHODS

Patients with NSCLC who were previously treated with one chemotherapy regimen and had a performance status of 0 or 1 were eligible. CPT-11 was administered at 60 mg/m² (level 1), 80 mg/m² (level 2) on days 1 and 8, and oral S-1 was administered at 80 mg/day for body surface area (BSA) less than 1.25 m², 100 mg/day for BSA 1.25-1.5 m², and 120 mg/day for BSA more than 1.5 m² on days 1-14 every 3 weeks. The dose-limiting toxicity (DLT) was defined as grade 4 leukocytopenia or neutropenia, grade ≥ 3 neutropenia with fever over 38°C, grade ≥ 3 thrombocytopenia, or grade ≥ 3 major nonhematological toxicities.

RESULTS

Nine patients were enrolled in the study. None of 3 patients enrolled in level 1 had any DLT. Of 6 patients in level 2, 2 patients had grade 3 diarrhea and one had grade 3 interstitial pneumonia. Level 1 was declared as the recommended dose.

CONCLUSION

The feasibility of the combination therapy of S-1 and CPT-11 was shown in the second-line setting for the treatment of advanced NSCLC. The recommended dose of CPT-11 was 60 mg/m² combined with standard dose of S-1 for phase II trials of pretreated advanced NSCLC patients.

A phase II study of combination therapy with irinotecan and S-1 (IRIS) in patients with advanced colorectal cancer

PURPOSE

A combination of irinotecan with continuous infusional 5-fluorouracil (5-FU) is the standard treatment for advanced colorectal cancer. The aim of this study was to determine the efficacy and safety of combining irinotecan and S-1 (IRIS) in patients with advanced colorectal cancer.

METHODS

Irinotecan was administered as an intravenous infusion at a dose of 120 mg/m(2) on day 1 and 15. And S-1 was administered orally on days 1-14 of a 28-day cycle. S-1 was given orally at a dose that did not exceed 40 mg/m(2) based BSA: BSA < 1.25 m(2), 40 mg twice daily; 1.25-1.5 m(2), 50 mg twice daily, and BSA > 1.5 m(2), 60 mg twice daily, for 14 consecutive days.

RESULTS

A total of 38 patients were enrolled. An intent-to-treat analysis showed a complete response and partial response to occur in 13.2% and 50.0%, respectively. The disease control rate was 84.2%. The median progression-free survival and overall survival were 10.0 months and 29.1 months, respectively. The rates of grade 3/4 toxicity over 4 cycles were the following: neutropenia, 15.8%; leucopenia, 7.9%; anorexia, 15.8%; diarrhea, 10.5%.

CONCLUSION

IRIS is an effective, well tolerated and convenient treatment regimen for patients with advanced colorectal cancer.