Efficacy and safety results after >3.5 years of treatment with the Bruton's tyrosine kinase inhibitor evobrutinib in relapsing multiple sclerosis: Long-term follow-up of a Phase II randomised clinical trial with a cerebrospinal fluid sub-study.

BACKGROUND: Evobrutinib - an oral, central nervous system (CNS)-penetrant, and highly selective Bruton's tyrosine kinase inhibitor - has shown efficacy in a 48-week, double-blind, Phase II trial in patients with relapsing MS. OBJECTIVE: Report results of the Phase II open-label extension (OLE; up to week 192 from randomisation) and a cerebrospinal fluid (CSF) sub-study. METHODS: In the 48-week double-blind period (DBP), patients received evobrutinib 25 mg once-daily, 75 mg once-daily, 75 mg twice-daily or placebo (switched to evobrutinib 25 mg once-daily after week 24). Patients could then enter the OLE, receiving evobrutinib 75 mg once-daily (mean (± standard deviation (SD)) duration = 50.6 weeks (±6.0)) before switching to 75 mg twice-daily. RESULTS: Of 164 evobrutinib-treated patients who entered the OLE, 128 (78.0%) completed ⩾192 weeks of treatment. Patients receiving DBP evobrutinib 75 mg twice-daily: annualised relapse rate at week 48 (0.11 (95% confidence interval (CI) = 0.04-0.25)) was maintained with the OLE twice-daily dose up to week 192 (0.11 (0.05-0.22)); Expanded Disability Status Scale score remained stable; serum neurofilament light chain fell to levels like a non-MS population (Z-scores); T1 gadolinium-enhancing lesion numbers remained low. No new safety signals were identified. In the OLE, evobrutinib was detected in the CSF of all sub-study patients. CONCLUSION: Long-term evobrutinib treatment was well tolerated and associated with a sustained low level of disease activity. Evobrutinib was present in CSF at concentrations similar to plasma.

Evobrutinib pathway to its major metabolite M463-2 and insights from a biotransformation and DDI perspective.

Evobrutinib is a highly selective, covalent, central nervous system-penetrant Bruton's tyrosine kinase (BTK) inhibitor, currently in Phase III trials for the treatment of relapsing multiple sclerosis. One major circulating metabolite of evobrutinib has been previously identified as the racemic dihydro-diol M463-2 (MSC2430422) in a Phase I human mass balance study.Phenotyping experiments were conducted to confirm the metabolic pathway of evobrutinib to M463-2. Ratio of the enantiomers was determined by enantioselective liquid chromatography with tandem mass spectrometry analysis of plasma samples from humans and preclinical species. Drug-drug interaction (DDI) characterisation, evaluation of pharmacological activity on BTK, and off-target screening experiments followed assessing safety of the metabolite.The biotransformation of evobrutinib to M463-2 was determined to be a two-step process with a CYP-mediated oxidation acting to form an epoxide intermediate, which was further hydrolysed by soluble and mitochondrial epoxide hydrolase. Only the (S)-enantiomer was determined to be a major metabolite, the (R)-enantiomer was minor. In vitro studies demonstrated the (S)-enantiomer lacked clinically relevant pharmacological activity, off-target effects and DDIs.The biotransformation of evobrutinib to its major metabolite has been elucidated, with the major (S)-enantiomer being shown to pose no on/off target or DDI risks.

Population pharmacokinetic and pharmacodynamic modeling of evobrutinib in healthy adult participants.

Evobrutinib, a Bruton's tyrosine kinase (BTK) inhibitor, has shown therapeutic potential in relapsing multiple sclerosis. This analysis aimed to develop pharmacokinetic (PK) and pharmacodynamic (PD; BTK occupancy [BTKO]) models of evobrutinib and simulate PK and BTKO profiles under alternative dosing regimens. Data were obtained from two phase I evobrutinib studies in healthy adult participants (Japanese and non-Japanese). Overall, 2326 observations were available from 76 participants; n = 42 from Study MS200527_0017 Part A received evobrutinib 25, 75, or 200 mg once-daily oral doses for 6 days while fasted; n = 18 from Study MS200527_0019 and n = 16 from Study MS200527_0017 Part B received single evobrutinib 75 mg oral doses with food (low-fat meal) and while fasted. Population PK/PD modeling for evobrutinib concentrations and BTKO (fraction unbound) were performed using nonlinear mixed-effects modeling. The effect of once-daily/twice-daily regimens and doses of 10-200 mg on BTKO were simulated. A two-compartment model with sequential zero-first order absorption and first-order elimination adequately described the data. Bioavailability increased by 49% with food compared with when fasted. There was no difference in PK parameters between Japanese and non-Japanese participants. The BTKO profile of evobrutinib was described by the irreversible binding population model. The simulated percentage of participants with minimum BTKO increased in a dose-dependent manner across the BTKO thresholds of interest (70%, 80%, 90%, and 95% occupancy). Evobrutinib doses of 25 mg once-daily, 50 mg twice-daily, or 75 mg twice-daily while fasted are possible choices for further development, assuming BTKO ≥70% at trough is needed to achieve efficacy.

Determination of a clinically effective evobrutinib dose: Exposure-response analyses of a phase II relapsing multiple sclerosis study.

The pharmacometric analysis of the double-blind, randomized, phase II study (NCT02975349) investigating the safety and efficacy of evobrutinib, explored exposure-response relationships and suitable dosing regimens of evobrutinib for relapsing multiple sclerosis. Population pharmacokinetic (PK)/pharmacodynamic modeling was applied to data collected in fasted patients treated with placebo or evobrutinib (25 mg once-daily [q.d.], 75 mg q.d., or 75 mg twice-daily [b.i.d.]) for 24 weeks, followed by a 24-week blinded extension (placebo patients switched to 25 mg q.d.). Model-based exposures for PK and Bruton's tyrosine kinase occupancy (BTKO) were used for exposure-response analyses (maximum 207 patients). PK, BTKO profiles, and annualized relapse rate (ARR) after 48 weeks of treatment under alternative dosing regimens were simulated. Exposure-response modeling identified a relationship between evobrutinib exposure and clinical response for total number of T1 Gd+ and new/enlarging T2 lesions at weeks 12-24, and ARR at week 48. Area under the concentration-time curve over 24 h at steady-state (AUC0-24,SS ) of 468 and ≥400 ng/ml h was associated with T1 Gd+/T2 lesion reduction and ARR improvement, respectively. These exposures were associated with steady-state (SS) predose BTKO ≥95%. Based on PK and BTKO profile simulations, evobrutinib 75 mg b.i.d. while fasted is predicted to maintain SS predose BTKO >95% in 92% of patients. Evobrutinib 45 mg b.i.d. with food is predicted to achieve similar exposure as 75 mg b.i.d. while fasted (predose BTKO >95% in 93% of patients). Evobrutinib 45 mg b.i.d. with food is predicted to have comparable exposure and BTKO to 75 mg b.i.d. without food (phase II) and will be pharmacologically effective and appropriate for clinical use in phase III multiple sclerosis studies.

Evobrutinib, a covalent Bruton's tyrosine kinase inhibitor: Mass balance, elimination route, and metabolism in healthy participants.

The highly selective, covalent Bruton's tyrosine kinase inhibitor evobrutinib is under investigation for treatment of patients with multiple sclerosis (MS). Early clinical studies in healthy participants and patients with relapsing MS indicated that evobrutinib is well-tolerated and effective. We undertook a mass balance study in six men who received a single 75-mg oral dose of evobrutinib containing ~ 3.6 MBq (100 µCi) 14 C-evobrutinib, to determine the absorption, metabolic pathways, and routes of excretion of evobrutinib. The primary objectives of this phase I study (NCT03725072) were to (1) determine the rates and routes of total radioactivity excretion, including the mass balance of total drug-related radioactivity in urine and feces, (2) assess the pharmacokinetics (PKs) of total radioactivity in blood and plasma, and (3) characterize the plasma PKs of evobrutinib. Exploratory end points included identifying and quantifying evobrutinib and its metabolites in plasma and excreta (urine and feces) and exploring key biotransformation pathways and clearance mechanisms. Evobrutinib was primarily eliminated in feces (arithmetic mean percentage, SD, 71.0, 2.1) and, to a lesser extent, in urine (20.6, 2.0), with most of the total radioactivity (85.3%) excreted in the first 72 h after administration. No unchanged evobrutinib was detected in excreta. Evobrutinib was rapidly absorbed and substantially metabolized upon absorption. Only one major metabolite M463-2 (MSC2430422) was identified in plasma above the 10% of total drug exposure threshold, which classifies M463-2 (MSC2430422) as a major metabolite according to the US Food and Drug Administration (FDA; metabolites in safety testing [MIST]) and the European Medicines Agency (EMA; International Conference on Harmonization [ICH] M3). These results support further development of evobrutinib and may help inform subsequent investigations.

Phase I, first-in-human trial of Bruton's tyrosine kinase inhibitor M7583 in patients with B-cell malignancies.

M7583 is a potent, highly selective, covalent BTK inhibitor in development. In this phase I, first-in-human, open label, multicenter dose-escalation trial, M7583 was given at 80 mg (three days)/160 mg (full 28-day cycle), then 300 mg/day, 600 mg/day, 900 mg/day, and 300 mg twice daily to 18 patients (median age 63 years) with refractory/resistant, stage III/IV B-cell malignancies who failed prior therapy (NCT02825836). No dose-limiting toxicities were reported. Treatment-emergent adverse events (AEs) occurred in 89% of patients, treatment-related AEs in 78%, and treatment-related grade ≥3 AEs in 17%. Common AEs were diarrhea (33%), fatigue (22%), and vomiting (17%). M7583 was rapidly absorbed and exposure was dose-proportional. BTK occupancy was >95% in the 300 mg twice daily and 900 mg/day cohorts. Objective response rate was 50% and disease control rate 78%, supporting a favorable benefit:risk profile. Fasted doses up to 900 mg once daily and 300 mg twice daily were well tolerated and may be tested in future clinical studies.

A Novel PBPK Modeling Approach to Assess Cytochrome P450 Mediated Drug-Drug Interaction Potential of the Cytotoxic Prodrug Evofosfamide.

Evofosfamide is a cytotoxic small-molecule prodrug preferentially activated under hypoxic conditions. The cytotoxicity of evofosfamide impacted the generation of in vitro drug-drug interaction (DDI) data, especially in vitro induction results. Therefore, a novel physiologically based pharmacokinetic (PBPK) approach was used, which involved available in vitro and clinical data of evofosfamide and combined it with induction data from the prototypical cytochrome P450 (CYP)3A inducer rifampicin. The area under the concentration-time curve (AUC) ratios of midazolam were above 0.80, indicating that induction of CYP3A by evofosfamide administered weekly is unlikely to occur in humans. Moreover, static and PBPK modeling showed no clinically relevant inhibition via CYP2B6, CYP2D6, and CYP3A4. In conclusion, PBPK models were used to supplement in vitro information of a cytotoxic compound. This approach may set a precedent for future studies of cytotoxic drugs, potentially reducing the need for clinical DDI studies and providing more confidence in the clinical use of approved cytotoxic compounds for which DDI information is sparse.

Mechanistic investigation of N,N-diethyl-4-(phenyl-piperidin-4-ylidenemethyl)-benzamide-induced insulin depletion in the rat and RINm5F cells.

These studies describe the effect of N,N-diethyl-4-(phenyl-piperidin-4-ylidenemethyl)-benzamide (AR-M100390), a delta-opioid agonist, on the pancreas and its mechanisms for pancreatic toxicity. Rats were treated with 5, 100, and 600 micromol/kg of AR-M100390 for 3 and/or 7 days; another group of rats treated with 600 micromol/kg of compound were allowed to recover for 14 days. AR-M100390 (600 micromol/kg) caused vacuolation in the beta-cell of the rat pancreas that was associated with depletion of insulin and hyperglycemia after 7 days of dosing. The loss of insulin by AR-M100390 was due to specific inhibition of rat insulin2 mRNA transcription in vivo. Insulin depletion and hyperglycemia were reversible. The effects of AR-M100390 in rats were reproduced in the rat pancreatic beta-cell line RINm5F, where it inhibited intracellular insulin content and secretion without affecting cell survival. Loss of insulin in vitro was also a result of specific inhibition of insulin2 mRNA transcription and was reversible. Pretreatment of cells with the delta-opioid antagonist naltrindole or pertussis toxin did not reverse loss of insulin in AR-M100390-treated cells suggesting that the effects were not mediated by the delta-opioid receptor. AR-M100390 inhibited KCl-mediated calcium mobilization in RINm5F cells, suggesting that L-type calcium channels found in these cells and in pancreatic beta-cells may partially play a role in the inhibition of insulin secretion by this compound. In summary, the in vitro and in vivo studies suggest that inhibition of insulin by AR-M100390 is due to a combination of inhibition of insulin synthesis and/or release.

Pyridazinoquinolinetriones as NMDA glycine-site antagonists with oral antinociceptive activity in a model of neuropathic pain.

A series of 7-chloro-2,3-dihydro-2-[1-(pyridinyl)alkyl]-pyridazino[4,5-b]quinoline-1,4,10(5H)-triones were synthesized and found to have potent activity at the glycine site of the NMDA receptor. In some cases, these compounds possessed poor aqueous solubility that may have contributed to poor rat oral bioavailability. Subsequently, compounds have been identified with improved aqueous solubility and oral bioavailability. Several of these compounds were examined in a rat chronic constrictive injury (CCI) model of neuropathic pain and found to have potent activity when dosed orally.

Synthesis of 7-chloro-2,3-dihydro-2-[1-(pyridinyl)alkyl]-pyridazino[4,5-b]quinoline-1,4,10(5H)-triones as NMDA glycine-site antagonists.

Several members of the 7-chloro-2,3-dihydro-2-[1-(pyridinyl)alkyl]-pyridazino[4,5-b]quinoline-1,4,10(5H)-triones (2) have been identified as being potent and selective NMDA glycine-site antagonists. Increasing size of the alkyl substituent on the alpha-carbon led to a progressive decrease in binding affinity. Some of these analogues possess improved drug-like properties such as cellular permeability, solubility and oral absorption.