Ruxolitinib exposure in patients with acute and chronic graft versus host disease in routine clinical practice-a prospective single-center trial.

Knowledge on Ruxolitinib exposure in patients with graft versus host disease (GvHD) is scarce. The purpose of this prospective study was to analyze Ruxolitinib concentrations of GvHD patients and to investigate effects of CYP3A4 and CYP2C9 inhibitors and other covariates as well as concentration-dependent effects. 262 blood samples of 29 patients with acute or chronic GvHD who were administered Ruxolitinib during clinical routine were analyzed. A population pharmacokinetic model obtained from myelofibrosis patients was adapted to our population and was used to identify relevant pharmacokinetic properties and covariates on drug exposure. Relationships between Ruxolitinib exposure and adverse events were assessed. Median of individual mean trough serum concentrations was 39.9 ng/mL at 10 mg twice daily (IQR 27.1 ng/mL, range 5.6-99.8 ng/mL). Applying a population pharmacokinetic model revealed that concentrations in our cohort were significantly higher compared to myelofibrosis patients receiving the same daily dose (p < 0.001). Increased Ruxolitinib exposure was caused by a significant reduction in Ruxolitinib clearance by approximately 50%. Additional comedication with at least one strong CYP3A4 or CYP2C9 inhibitor led to a further reduction by 15% (p < 0.05). No other covariate affected pharmacokinetics significantly. Mean trough concentrations of patients requiring dose reduction related to adverse events were significantly elevated (p < 0.05). Ruxolitinib exposure is increased in GvHD patients in comparison to myelofibrosis patients due to reduced clearance and comedication with CYP3A4 or CYP2C9 inhibitors. Elevated Ruxolitinib trough concentrations might be a surrogate for toxicity.

Isberner N ，Kraus S ，Grigoleit GU ，Aghai F ，Kurlbaum M ，Zimmermann S ，Klinker H ，Scherf-Clavel O ... -  《-》

Drug-drug interaction (DDI) assessments of ruxolitinib, a dual substrate of CYP3A4 and CYP2C9, using a verified physiologically based pharmacokinetic (PBPK) model to support regulatory submissions.

Umehara K ，Huth F ，Jin Y ，Schiller H ，Aslanis V ，Heimbach T ，He H ... -  《-》

Pharmacokinetics of Ruxolitinib in HIV Suppressed Individuals on Antiretroviral Agent Therapy from the ACTG A5336 Study.

Ruxolitinib is a US Food and Drug Administration-approved orally administered Janus kinase (1/2) inhibitor that reduces cytokine-induced inflammation. As part of a randomized, phase 2, open-label trial, ruxolitinib (10 mg twice daily) was administered to HIV-positive, virologically suppressed individuals (33 men, 7 women) on antiretroviral therapy (ART) for 5 weeks. Herein, we report the population PK subsequently determined from this study. Plasma concentrations of ruxolitinib (294 samples) and antiretroviral agents were measured at week 1 (N = 39 participants) and week 4 or 5 (N = 37). Ruxolitinib PK was adequately described with a 2-compartment model with first-order absorption and elimination with distribution volumes normalized to mean body weight (91.5 kg) and a separate typical clearance for participants administered efavirenz (a known cytochrome P450 3A4 inducer). Participants administered an ART regimen with efavirenz had an elevated typical apparent oral clearance versus the integrase inhibitor regimen group (22.5 vs 12.9 L/hr; N = 14 vs 25). Post hoc predicted apparent oral clearance was likewise more variable and higher (P < .0001) in those administered efavirenz. There was  an ≈25% variation in ruxolitinib plasma exposures between week 1 and week 4/5. ART plasma concentrations resembled those from PK studies without ruxolitinib. Therefore, integrase inhibitor-based ART regimens may be preferred over efavirenz-based regimens when ruxolitinib is administered to HIV-positive individuals.

Hurwitz SJ ，Tao S ，Gavegnano C ，Jiang Y ，Tressler RL ，Tsibris A ，Del Rio C ，Overton ET ，Lederman MM ，Kantor A ，Moser C ，Kohler JJ ，Lennox J ，Marconi VC ，Flexner CW ，Schinazi RF ... -  《-》

Ruxolitinib for chronic steroid-refractory graft versus host disease: a single center experience.

Chronic Graft versus Host Disease (GvHD) is a serious complication of allogeneic hematopoietic stem cell transplant that severely impacts quality of life and long-term survival. About 50-to-60 % of patients treated with steroids require a further line of therapy due to lack of sustained response. Ruxolitinib, a JAK1/2 inhibitor, has recently been approved for the treatment of acute GvHD. We aimed to retrospectively evaluate ruxolitinib efficacy and safety in a cohort of patients diagnosed with moderate (25 %) or severe (75 %) steroid-refractory or steroid-dependent chronic GvHD. Response evaluation was performed at three and six months. Thirty-six patients received ruxolitinib after a median of three previous lines (range, r 1-11) for a median of 8.6 months (r 1-51.6). Cutaneous GvHD was the most frequent presentation. We observed an overall response of 59 % (CR 9%, PR 50 %) at three months and 62 % (CR 15 %, PR 46 %) at six months. Two patients had hematologic disease recurrence and were censored at relapse; no other permanent discontinuation due to adverse events were documented. Cutaneous, oral, genital and ocular GvHD significantly improved after treatment. 2-year overall survival and 2-year transplant related mortality were 74 % and 19 % respectively. Ruxolitinib was associated with a significant reduction of steroid dose. Ruxolitinib was confirmed to be a safe and effective option as salvage treatment also for advanced stages of chronic GvHD. Longer follow up is needed to evaluate durability of response. Prospective analyses on larger cohorts are ongoing.

Xue E ，Lorentino F ，Pavesi F ，Assanelli A ，Peccatori J ，Bernardi M ，Corti C ，Ciceri F ，Lupo Stanghellini MT ... -  《-》

Multiple administrations of fluconazole increase plasma exposure to ruxolitinib in healthy adult subjects.

Aslanis V ，Umehara K ，Huth F ，Ouatas T ，Bharathy S ，Butler AA ，Zhou W ，Gadbaw B ... -  《-》