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Fedratinib is an oral Janus kinase 2-selective inhibitor for the treatment of adult patients with intermediate-2 or high-risk myelofibrosis; however, some patients have difficulty with oral dosing. This randomized, phase 1, open-label, 2-part crossover study evaluated the relative bioavailability, safety, tolerability, taste, and palatability of fedratinib resulting from various alternative oral administration methods in healthy adults. Participants could receive fedratinib 400 mg orally as intact capsules along with a nutritional supplement; as contents of capsules dispersed in a nutritional supplement, delivered via nasogastric tube; or as a divided dose of 200 mg orally twice daily as intact capsules with a nutritional supplement. Fifty-eight participants received treatment. Total exposure to fedratinib was similar after oral administration of intact capsules or when dispersed in a nutritional supplement (area under the plasma concentration–time curve from time 0 to the time of the last quantifiable concentration geometric mean ratio [AUC0–t GMR] [90% CI], 1.007 [0.929–1.092]). Total exposure to fedratinib was slightly reduced following nasogastric administration (AUC0–t GMR 0.850 [0.802–0.901]) and as a divided dose (AUC0–t GMR 0.836 [0.789–0.886]). No new safety signals were identified for fedratinib, and most participants found the taste and palatability acceptable when dispersed in a nutritional supplement. Overall, results suggest no clinically meaningful differences in total exposure to fedratinib between the tested oral administration methods. These findings may facilitate administration of fedratinib to patients who are intolerant of swallowing the capsule dosage form. (ClinicalTrials.gov: NCT05051553). [ABSTRACT FROM AUTHOR]

Purpose: Fedratinib is an orally administered Janus kinase (JAK) 2-selective inhibitor for the treatment of adult patients with intermediate-2 or high-risk primary or secondary myelofibrosis. In vitro, fedratinib is predominantly metabolized by cytochrome P450 (CYP) 3A4 and to a lesser extent by CYP2C19. Coadministration of fedratinib with CYP3A4 inhibitors is predicted to increase systemic exposure to fedratinib. This study evaluated the effect of multiple doses of the dual CYP3A4 and CYP2C19 inhibitor, fluconazole, on the pharmacokinetics of a single dose of fedratinib.Methods: In this non-randomized, fixed-sequence, open-label study, healthy adult participants first received a single oral dose of fedratinib 100 mg on day 1. Participants then received fluconazole 400 mg on day 10 and fluconazole 200 mg once daily on days 11-23, with a single oral dose of fedratinib 100 mg on day 18. Pharmacokinetic parameters were calculated for fedratinib administered with and without fluconazole.Results: A total of 16 participants completed the study and were included in the pharmacokinetic population. Coadministration of fedratinib with fluconazole increased maximum observed plasma concentration (Cmax) and area under the plasma concentration-time curve from time 0 to the last quantifiable concentration (AUC0-t) of fedratinib by 21% and 56%, respectively, compared with fedratinib alone. Single oral doses of fedratinib 100 mg administered with or without fluconazole were well tolerated.Conclusions: Systemic exposure after a single oral dose of fedratinib was increased by up to 56% when fedratinib was coadministered with fluconazole compared with fedratinib alone.Trial Registry: CLINICALTRIALS.GOV: NCT04702464. [ABSTRACT FROM AUTHOR]

Introduction: Fedratinib, an oral, selective Janus kinase 2 inhibitor, has been shown to inhibit P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporting polypeptide (OATP) 1B1, OATP1B3, organic cation transporter (OCT) 2, and multidrug and toxin extrusion (MATE) 1 and MATE2-K in vitro. The objective of this study was to evaluate the influence of fedratinib on the pharmacokinetics (PK) of digoxin (P-gp substrate), rosuvastatin (OATP1B1/1B3 and BCRP substrate), and metformin (OCT2 and MATE1/2-K substrate).Methods: In this nonrandomized, fixed-sequence, open-label study, 24 healthy adult participants received single oral doses of digoxin 0.25 mg, rosuvastatin 10 mg, and metformin 1000 mg administered as a drug cocktail (day 1, period 1). After a 6-day washout, participants received oral fedratinib 600 mg 1 h before the cocktail on day 7 (period 2). An oral glucose tolerance test (OGTT) was performed to determine possible influences of fedratinib on the antihyperglycemic effect of metformin.Results: Plasma exposure to the three probe drugs was generally comparable in the presence or absence of fedratinib. Reduced metformin renal clearance by 36% and slightly higher plasma glucose levels after OGTT were observed in the presence of fedratinib. Single oral doses of the cocktail ± fedratinib were generally well tolerated.Conclusions: These results suggest that fedratinib has minimal impact on the exposure of P-gp, BCRP, OATP1B1/1B3, OCT2, and MATE1/2-K substrates. Since renal clearance of metformin was decreased in the presence of fedratinib, caution should be exercised in using coadministered drugs that are renally excreted via OCT2 and MATEs.Trial Registration: Clinicaltrials.gov NCT04231435 on January 18, 2020. [ABSTRACT FROM AUTHOR]

Purpose: Fedratinib is an oral and selective Janus kinase 2 inhibitor that is indicated for treatment of adults with intermediate-2 or high-risk primary or secondary myelofibrosis. Fedratinib is metabolized by cytochrome P450s (CYPs), primarily CYP3A4. The objective of this study was to determine the effects of the strong CYP3A4 inducer rifampin and moderate CYP3A4 inducer efavirenz on the pharmacokinetics of single doses of fedratinib. Methods: This Phase 1, open-label, two-part study (Part 1 for rifampin and Part 2 for efavirenz) was conducted in healthy adult men and women. A single dose of fedratinib (500 mg) was administered on Day 1. Participants received rifampin 600 mg daily or efavirenz 600 mg daily on Days 9–18. On Day 17, a single dose of fedratinib (500 mg) was coadministered with rifampin or efavirenz. Plasma fedratinib concentrations were measured using validated liquid chromatography–tandem mass spectrometry. Results: Maximum observed plasma fedratinib concentrations were lowered by approximately 70% and 30% during coadministration with rifampin or efavirenz, respectively, compared with fedratinib alone. Geometric means of fedratinib area under the plasma concentration–time curve from 0 to infinity were decreased by 81% (90% confidence interval [CI], 77–83%) and 47% (90% CI, 40–53%) during coadministration with rifampin or efavirenz, respectively. Fedratinib was generally well tolerated when administered alone or in combination with rifampin or efavirenz. Conclusion: Significant reductions in fedratinib exposure were observed in the presence of strong or moderate CYP3A4 inducers. These results suggest that agents that are strong or moderate inducers of CYP3A4 should be avoided when coadministered with fedratinib. Trial Registration Number: NCT03983239 (Registration date: June 12, 2019). [ABSTRACT FROM AUTHOR]