Mitomycin C and high-dose 5-fluorouracil with folinic acid as a therapeutic option for heavily pretreated patients with metastatic colorectal cancer: prospective phase II trial

The effect of Mitomycin-C in neoadjuvant concurrent chemoradiotherapy for rectal cancer

BACKGROUND

Neoadjuvant concurrent chemoradiotherapy (nCCRT) followed by total mesorectal excision has become the standard of care for advanced rectal cancer, but the most effective regimen of chemotherapeutic agents has not yet been determined. The purpose of this study is to determine the effect of Mitomycin-C (MMC) in nCCRT for rectal cancer.

METHODS

From 2000 to 2017, patients with rectal adenocarcinoma who received nCCRT followed by radical surgery were enrolled in our study. The patients were retrospectively separated into two groups according to nCCRT regimens (with or without MMC). Other factors related to cancer down-staging after nCCRT, disease-free survival (DFS) and overall survival (OS) were analyzed.

RESULTS

One hundred ninety-five patients received radiotherapy (RT) + MMC + oral tegafur-uracil (UFUR), and 191 patients received RT + UFUR without MMC as neoadjuvant CCRT. Adding MMC might increase the down-staging rate (odds ratio [OR] = 1.520, p = 0.058), and down-staging had significant effect to improve OS (OR = 1.726, p = 0.002) and DFS (OR = 2.185, p < 0.001). The OS and DFS were improved in patients who received MMC, although this result did not reach a statistically significant difference. There was a higher incidence of low-grade toxicities in the MMC group, especially neutropenia, genitourinary side effects, and dermatological side effects ( p < 0.001).

CONCLUSION

Adding MMC to the regimen of nCCRT for rectal adenocarcinoma is shown to increase tumor down-staging rate and improve disease-free and OS, although these benefits come at the cost of increased low-grade toxicities. Prospective randomized studies are needed to explore the role of MMC in nCCRT for rectal cancer.

A systematic review of salvage therapies in refractory metastatic colorectal cancer

PURPOSE

Established that the only approved agents in previously treated metastatic colorectal cancer (CRC) are trifluoridine/tipiracil and regorafenib, we conducted a systematic review of all the published phase 2-3 trials, with the scope to evaluate the benefit of any later-line regimens in refractory metastatic CRC.

METHODS

Phase 2-3 studies that enrolled patients with stage IV disease receiving salvage therapies for refractory CRC were identified using electronic databases (Pubmed, EMBASE, and Cochrane Library). Clinical outcomes were pooled using a point estimates for the weighted values of median overall survival (OS), progression-free survival (PFS), response rate (ORR), stable disease rate (SD), and 6-month and 1-year OS.

RESULTS

Overall, 7556 patients were included from 67 studies (n = 70 arms). Overall, the pooled ORR and SD were 15.4% (95% CI 13-18%) and 36.9% (95% CI 33.5-40.6%). Median PFS, 6-month and 1-year OS, and median OS were 3.2 (95% CI 2.9-3.3) months, 65.4% (95% CI 61.9-68.8%), 36% (95% CI 32.3-39.9%) and 8.8 (95% CI 8.3-9.2) months. Overall survival was different in the monochemotherapy, polychemotherapy, chemotherapy + targeted therapy, and targeted therapy alone arms (7.6, 9.5, 10.3, and 7.9 months, respectively, P for difference = 0.01). Median PFS were respectively 2.3, 3.9, 3.8, and 2.6, respectively (P for difference < 0.01).

CONCLUSIONS

Overall, combination therapy (polychemotherapy with or without targeted agents) is associated with a higher control of disease and better outcome than approved agents. Treatment, if possible, should be personalized according to the patients' conditions, physician preference and molecular profile of disease.

Population Pharmacokinetic-Pharmacodynamic Modeling of 5-Fluorouracil for Toxicities in Rats

BACKGROUND AND OBJECTIVES

Myelosuppression is a dose-limiting toxicity of 5-fluorouracil (5-FU). Predicting the inter- and intra-patient variability in pharmacokinetics and toxicities of 5-FU may contribute to the individualized medicine. This study aimed to establish a population pharmacokinetic-pharmacodynamic model that could evaluate the inter- and intra-individual variability in the plasma 5-FU concentration, 5-FU-induced body weight loss and myelosuppression in rats.

METHOD

Plasma 5-FU concentrations, body weight loss, and blood cell counts in rats following the intravenous administration of various doses of 5-FU for 4 days were used to develop the population pharmacokinetic-pharmacodynamic model.

RESULTS

The population pharmacokinetic model consisting of a two-compartment model with Michaelis-Menten elimination kinetics successfully characterized the individual and population predictions of the plasma concentration of 5-FU and provided credible parameter estimates. The estimates of inter-individual variability in maximal rate of saturable metabolism and residual variability were 8.1 and 22.0%, respectively. The population pharmacokinetic-pharmacodynamic model adequately described the individual complete time-course of alterations in body weight loss, erythrocyte, leukocyte, and lymphocyte counts in rats treated with various doses of 5-FU. The inter-individual variability of the drug effects in the pharmacodynamic model for body weight loss was 82.6%, which was relatively high. The results of the present study suggest that not only individual fluctuations in the 5-FU concentration but also the cell sensitivity would affect the onset and degree of 5-FU-induced toxicity.

CONCLUSION

This population pharmacokinetic-pharmacodynamic model could evaluate the inter- and intra-individual variability in drug-induced toxicity and guide the assessments of novel anticancer agents in drug development.

Mitomycin-C+fluoropyrimidines in heavily pretreated metastatic colorectal cancer: a systematic review and evidence synthesis

Mitomycin-C (MMC) combined with fluoropyrimidines has historically been used for pretreated patients with some activity in this setting, in particular, as third-line chemotherapy (CT) or beyond. We have evaluated the efficacy and safety of MMC-based therapy as a further line of CT in advanced colorectal cancer. Prospective or retrospective studies of MMC-based CT were included in the pooled analysis. PubMed, EMBASE, SCOPUS, Web of Science, the Cochrane Library database and CINAHL were searched systematically. The outcomes were progression-free survival, overall survival, overall response rate and grades 3-4 drug-related adverse events. Seventeen trials involving 681 patients were included in the analysis. Overall, the pooled average weighted progression-free survival and overall survival were 2.84 [95% confidence interval (CI) 2.5-3.1] and 7.47 (95% CI 6-8.9) months, respectively. The corresponding pooled overall response rate was 7.2% (95% CI 5.2-9.9%) and the pooled disease control rate was 38.7% (95% CI 31.7-46.3%). The G3-4 neutropenia and anaemia were the most frequent haematological toxicities (range 0-20%). Nonhaematological G3-4 toxicities were compatible with the associated agent. MMC with fluoropyrimidines represents a viable and active combination for pretreated metastatic colorectal cancer patients. It is thus an option when other agents have failed, or are unavailable or not indicated.

Immunomodulatory Response Triggered by the Alkaloids, 3-Amino-7-Benzylbenzimidazo[3,2-a] Quinolinium Chloride (ABQ-48) and 3-Nitro-7-Benzylbenzimidazo [3,2-a] Quinolinium Chloride (NBQ-48)

ABQ-48 (3-amino-7-benzylbenzimidazo[3,2-a]quinolinium chloride) and NBQ-48 (3-nitro-7-benzylbenzimidaw[3,2-a] quinolinium chloride) are un-natural alkaloids containing a planar heteroaromatic systems characterized by quaternized nitrogen fused to benzothiazole nucleus. Both compounds are structurally related to naturally occurring substances such as elliptine (from Ochrosia), and berberine (from Berberis). Previous in vitro studies have shown these agents to control tumor-cell proliferation indicating that both BQS are active but especially ABQ-48 at a 1 OuM dose with over 80% control of the proliferation of multiple cancer cell lines from various etiologies including colon, melanoma, CNS and ovarian cells. Mechanism of action studies have also been conducted however this is the first approach to evaluate immune modulatory activity of these novel BQS. Immune-based therapy is an increasing field in which scientists identify how the immunomodulatory activity of known and newly discovered compounds elicits an immune response that could be used against diseases. In this study, our main objective was to apply an in vitro model to show the immunomodulatory effects of ABQ-48 and NBQ-48 by analyzing the cytokine profile resulting after extracted murine spleen cells were treated with both BQS using a fluorescence-based multiplex ELISA approach. Screened cytokines included: G-CSF, GM-CSF, IL-1a, IL-2, IL-3, IL-5, IL-6, IL-7, IL-10, IL-12p70, IL-13, IL-15, IL-17, IL-21, IL-23, IFN-γ, and TNF-α. Our study results show ABQ 48 and NBQ-48 to stimulate the release of G-CSF, IL-2, IL-6, and, IFN-γ when mouse splenocytes are incubated with serial dilutions of these agents. Our finding opens new possibilities of potentially using ABQ-48 and NBQ-48 as immunomodulatory agents; with intend to activate the immune system such as the production of neutrophils against cancer or reducing chemotherapy side effects.

Semi-physiological pharmacokinetic-pharmacodynamic (PK-PD) modeling and simulation of 5-fluorouracil for thrombocytopenia in rats

1. The aim of this study was to develop a simple pharmacokinetic-pharmacodynamic (PK-PD) model that could characterize the complete time-course of alterations in platelet counts to predict the onset and degree of thrombocytopenia, which severely limits the use of the anticancer agent 5-fluorouracil (5-FU), in rats. 2. Platelet counts were measured in rats following the intravenous administration of various doses of 5-FU for 4 days to obtain data for an analysis of the PK-PD model. Our PK-PD model consisted of a two-compartment PK model, with three compartments for the PD model and 10 structural PK-PD model parameters. 3. After the 5-FU treatment, platelet counts transiently decreased to a nadir level, showed a rebound to above the baseline level before recovering to baseline levels. Nadir platelet counts and rebounds varied with the AUC0-∞ level. The final PK-PD model effectively characterized platelet count data and final PD parameters were estimated with high certainty. 4. This PK-PD model and simulation may represent a valuable tool for quantifying and predicting the complete time-course of alterations in blood cell counts, and could contribute to the development of therapeutic strategies with 5-FU and assessments of various novel anticancer agents that are difficult to examine in humans.