5-fluorouracil (5-FU) is widely used in the treatment of cancer. Over the past 20 years, increased understanding of the mechanism of action of 5-FU has led to the development of strategies that increase its anticancer activity. Despite these advances, drug resistance remains a significant limitation to the clinical use of 5-FU. Emerging technologies, such as DNA microarray profiling, have the potential to identify novel genes that are involved in mediating resistance to 5-FU. Such target genes might prove to be therapeutically valuable as new targets for chemotherapy, or as predictive biomarkers of response to 5-FU-based chemotherapy.

5-Fluorouracil: mechanisms of action and clinical strategies

BACKGROUND Intravenous bolus fluorouracil plus leucovorin is the standard adjuvant treatment for colon cancer. The oral fluoropyrimidine capecitabine is an established alternative to bolus fluorouracil plus leucovorin as first-line treatment for metastatic colorectal cancer. We evaluated capecitabine in the adjuvant setting. METHODS We randomly assigned a total of 1987 patients with resected stage III colon cancer to receive either oral capecitabine (1004 patients) or bolus fluorouracil plus leucovorin (Mayo Clinic regimen; 983 patients) over a period of 24 weeks. The primary efficacy end point was at least equivalence in disease-free survival; the primary safety end point was the incidence of grade 3 or 4 toxic effects due to fluoropyrimidines. RESULTS Disease-free survival in the capecitabine group was at least equivalent to that in the fluorouracil-plus-leucovorin group (in the intention-to-treat analysis, P<0.001 for the comparison of the upper limit of the hazard ratio with the noninferiority margin of 1.20). Capecitabine improved relapse-free survival (hazard ratio, 0.86; 95 percent confidence interval, 0.74 to 0.99; P=0.04) and was associated with significantly fewer adverse events than fluorouracil plus leucovorin (P<0.001). CONCLUSIONS Oral capecitabine is an effective alternative to intravenous fluorouracil plus leucovorin in the adjuvant treatment of colon cancer.

https://www.nejm.org/doi/pdf/10.1056/NEJMoa043116

Capecitabine as Adjuvant Treatment for Stage III Colon Cancer

PURPOSE: To compare the response rate, efficacy parameters, and toxicity profile of oral capecitabine with bolus intravenous (IV) fluorouracil plus leucovorin (5-FU/LV) as first-line treatment in patients with metastatic colorectal cancer. PATIENTS AND METHODS: We prospectively randomized 605 patients to treatment with oral capecitabine for 14 days every 3 weeks or 5-FU/LV by rapid IV injection daily for 5 days in 4-week cycles. RESULTS: The overall objective tumor response rate among all randomized patients was significantly higher in the capecitabine group (24.8%) than in the 5-FU/LV group (15.5%; P = .005). In the capecitabine and 5-FU/LV groups, median times to disease progression were 4.3 and 4.7 months (log-rank P = .72), median times to treatment failure were 4.1 and 3.1 months (P = .19), and median overall survival times were 12.5 and 13.3 months (P = .974), respectively. Capecitabine, compared with bolus 5-FU/LV treatment, produced a significantly lower incidence (P < .0002) of diarrhea, stomatit...

Comparison of Oral Capecitabine Versus Intravenous Fluorouracil Plus Leucovorin as First-Line Treatment in 605 Patients With Metastatic Colorectal Cancer: Results of a Randomized Phase III Study

PURPOSE: Docetaxel and capecitabine, a tumor-activated oral fluoropyrimidine, show high single-agent efficacy in metastatic breast cancer (MBC) and synergy in preclinical studies. This international phase III trial compared efficacy and tolerability of capecitabine/docetaxel therapy with single-agent docetaxel in anthracycline-pretreated patients with MBC. PATIENTS AND METHODS: Patients were randomized to 21-day cycles of oral capecitabine 1,250 mg/m2 twice daily on days 1 to 14 plus docetaxel 75 mg/m2 on day 1 (n = 255) or to docetaxel 100 mg/m2 on day 1 (n = 256). RESULTS: Capecitabine/docetaxel resulted in significantly superior efficacy in time to disease progression (TTP) (hazard ratio, 0.652; 95% confidence interval [CI], 0.545 to 0.780; P = .0001; median, 6.1 v 4.2 months), overall survival (hazard ratio, 0.775; 95% CI, 0.634 to 0.947; P = .0126; median, 14.5 v 11.5 months), and objective tumor response rate (42% v 30%, P = .006) compared with docetaxel. Gastrointestinal side effects and hand-foot ...

Superior Survival With Capecitabine Plus Docetaxel Combination Therapy in Anthracycline-Pretreated Patients With Advanced Breast Cancer: Phase III Trial Results

Purpose To compare the efficacy and safety of orally administered capecitabine (Xeloda; Roche Laboratories, Inc, Nutley, NJ), a novel fluoropyrimidine carbamate designed to mimic continuous fluorouracil (5-FU) infusion but with preferential activation at the tumor site, with that of intravenous (IV) 5-FU plus leucovorin (5-FU/LV) as first-line treatment for metastatic colorectal cancer. Patients and methods We prospectively randomized 602 patients to treatment with capecitabine 1,250 mg/m(2) administered twice daily days 1 to 14 every 3 weeks, or to the 4-weekly Mayo Clinic regimen (5-FU/LV) until disease progression or unacceptable toxicity. Results The primary objective, to demonstrate at least equivalent response rates in the two treatment groups, was met. The overall response rate was 18.9% for capecitabine and 15.0% for 5-FU/LV. In the capecitabine and 5-FU/LV groups, respectively, median time to disease progression was 5.2 and 4.7 months (log-rank P =.65); median time to treatment failure was 4.2 and 4.0 months (log-rank P =.89); and median overall survival was 13.2 and 12.1 months (log-rank P =.33). The toxicity profiles of both treatments were typical of fluoropyrimidines. However, capecitabine led to significantly lower incidences (P Conclusion Oral capecitabine achieved an at least equivalent efficacy compared with IV 5-FU/LV. Capecitabine demonstrated clinically meaningful safety advantages and the convenience of an oral agent.

Oral Capecitabine Compared With Intravenous Fluorouracil Plus Leucovorin in Patients With Metastatic Colorectal Cancer: Results of a Large Phase III Study

Fluoroquinolone use in children is limited due to its potential toxicity and negative effects on skeletal development, but the actual effects/risks of fluoroquinolones on bone growth and the mechanisms behind fluoroquinolone-driven arthropathy remain unknown. Gepotidacin is a novel, bactericidal, first-in-class triazaacenaphthylene antibiotic with a unique mechanism of action that is not anticipated to have the same risks to bone growth as those of fluoroquinolones. ABSTRACT Fluoroquinolone use in children is limited due to its potential toxicity and negative effects on skeletal development, but the actual effects/risks of fluoroquinolones on bone growth and the mechanisms behind fluoroquinolone-driven arthropathy remain unknown. Gepotidacin is a novel, bactericidal, first-in-class triazaacenaphthylene antibiotic with a unique mechanism of action that is not anticipated to have the same risks to bone growth as those of fluoroquinolones. Gepotidacin is in phase III clinical development for uncomplicated urinary tract infections (ClinicalTrials.gov identifiers NCT04020341 and NCT04187144) and urogenital gonorrhea (ClinicalTrials.gov identifier NCT04010539) in adults and adolescents ≥12 years of age. To inform arthropathy and other potential toxicity risks of gepotidacin in pediatric studies, this nonclinical study assessed oral gepotidacin toxicity in juvenile rats from postnatal day (PND) 4 to PND 32/35 (approximately equivalent to human ages from newborn to 11 years), using both in-life assessments (tolerability, toxicity, and toxicokinetics) and terminal assessments (necropsy with macroscopic and microscopic skeletal femoral head and/or stifle joint examinations). Gepotidacin doses of ≤300 mg/kg of body weight/day were well tolerated from PND 4 to PND 21, and higher doses of ≤1,250 mg/kg/day were well tolerated from PND 22 when the dose levels were escalated to maintain systemic exposure levels up to PND 35, with no observed treatment-related clinical signs, effects on mean body weight gain, or macroscopic findings on articular surfaces. A dose of 1,000 mg/kg/day was not tolerated during the dosing period from PND 4 to 21, with effects on body weight gain, fecal consistency, and body condition. Microscopic effects on articular surfaces were evaluated after 32 days of gepotidacin treatment at the highest tolerated dose. After 32 days of treatment with the highest tolerated gepotidacin dose of 300/1,250 mg/kg/day (systemic concentrations [area under the curve {AUC} values] of 93.7 μg · h/mL [males] and 121 μg · h/mL [females]), no skeletal effects on articular surfaces of the femoral head or stifle joint were observed. The absence of treatment-related clinical signs and arthropathy in juvenile rats provides evidence to support the potential future use of gepotidacin in children.

Novel Bacterial Topoisomerase Inhibitor Gepotidacin Demonstrates Absence of Fluoroquinolone-Like Arthropathy in Juvenile Rats

Gepotidacin is a novel triazaacenaphthylene antibiotic in phase III development. Based on nonclinical in vitro characterization of gepotidacin metabolism, two phase I studies were conducted in healthy participants to investigate clinical drug–drug interactions (DDIs). We assessed gepotidacin as a DDI victim with a potent cytochrome P450 (CYP) 3A4/P‐glycoprotein (P‐gp) inhibitor (itraconazole), potent CYP3A4 inducer (rifampicin), and nonspecific organic cation transporter (OCT)/multidrug and toxic extrusion transporter (MATE) renal transport inhibitor (cimetidine) via single doses of gepotidacin before and after co‐administration with multiple doses of the modulator drugs. Gepotidacin DDI perpetrator potential for P‐gp inhibition (digoxin) and CYP3A4 inhibition (midazolam) was evaluated via single doses of the two‐drug cocktail without and with gepotidacin. The DDI magnitudes were interpreted based on area under the concentration‐time curve (AUC). A weak DDI (AUC increase 48%–50%) was observed for gepotidacin co‐administered with itraconazole. A clinically significant decrease in gepotidacin plasma AUC (52%) was observed with rifampicin coadministration, indicating a moderate DDI. There was no DDI for gepotidacin with cimetidine; a unique biomarker approach showed increased serum creatinine (24%), decreased renal clearance of creatinine (21%), and N1‐methylnicotinamide (39%), which confirmed extensive MATE inhibition and partial OCT2 inhibition. Gepotidacin was not a P‐gp DDI perpetrator, although the maximum plasma concentration of digoxin increased (53%) and is potentially clinically relevant given its narrow therapeutic index. Gepotidacin demonstrated weak CYP3A4 inhibition with midazolam (<2‐fold AUC increase). There were no new safety‐risk profile findings. These results will inform the safe and efficacious clinical use of gepotidacin when co‐administered with other drugs.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/cts.13477

Clinical assessment of gepotidacin (GSK2140944) as a victim and perpetrator of drug–drug interactions via CYP3A metabolism and transporters

Gepotidacin is a novel, bactericidal, first‐in‐class triazaacenaphthylene antibiotic in late‐phase development for uncomplicated urinary tract infection and uncomplicated urogenital gonorrhea. Two clinical studies were conducted to assess the pharmacokinetics (PK) and interethnic comparisons of oral gepotidacin (free‐base and to‐be‐marketed mesylate formulations) administered as single doses ranging from 1500 to 3000 mg in fed and fasted states, and as 2 × 3000‐mg doses given 12 hours apart under fed conditions in healthy participants of Japanese ancestry. Dose proportionality was observed in plasma exposures, and comparable area under the concentration‐time curve (AUC) and maximum concentration were observed in fed and fasted states. Interethnic comparisons for Japanese versus non‐Japanese participant data showed slightly higher plasma maximum concentration (7%‐30%) yet similar plasma AUCs; slightly lower urine AUCs (11%‐18%) were observed. The slightly higher plasma exposures in healthy Japanese versus White participants in the same study were attributed to lower mean body weights (64 kg versus ≈80 kg). Adverse events were primarily gastrointestinal, and when administered with food, gastrointestinal tolerability was improved. Overall, the gepotidacin PK and safety‐risk profiles in healthy Japanese support potential evaluation of the global clinical doses in future studies.

Pharmacokinetic, Safety, and Tolerability Evaluations of Gepotidacin (GSK2140944) in Healthy Japanese Participants

Twelve-week treatment with BOS-580, a novel, long-acting Fc-FGF-21 fusion protein, leads to a reduction in liver steatosis, liver injury, and fibrosis in patients with phenotypic NASH: a randomized, blinded, placebo-controlled phase 2A trial

Etienne Dumont

Papers

Novel Bacterial Topoisomerase Inhibitor Gepotidacin Demonstrates Absence of Fluoroquinolone-Like Arthropathy in Juvenile Rats

Clinical assessment of gepotidacin (GSK2140944) as a victim and perpetrator of drug–drug interactions via CYP3A metabolism and transporters

Pharmacokinetic, Safety, and Tolerability Evaluations of Gepotidacin (GSK2140944) in Healthy Japanese Participants

Twelve-week treatment with BOS-580, a novel, long-acting Fc-FGF-21 fusion protein, leads to a reduction in liver steatosis, liver injury, and fibrosis in patients with phenotypic NASH: a randomized, blinded, placebo-controlled phase 2A trial