Safety, Tolerability, and Pharmacodynamics of the ADAMTS-5 Nanobody M6495: Two Phase 1, Single-Center, Double-Blind, Randomized, Placebo-Controlled Studies in Healthy Subjects and Patients With Osteoarthritis

OBJECTIVE

To assess the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of single and multiple injections of M6495, a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5)  nanobody, in healthy volunteers and patients with osteoarthritis.

METHODS

Two randomized, placebo-controlled, double-blind studies were performed. Study 1 enrolled 54 healthy male volunteers who received one subcutaneous (s.c.) injection of M6495 (1-300 mg) or placebo (ratio 2:1), evaluating safety, PK, and PD as changes in the serum aggrecan fragment alanine-arginine-glycine-serine (ARGS). Study 2 enrolled 32 patients with osteoarthritis with Kellgren-Lawrence grades 2 to 4 and pain greater than or equal to 40 on the Western Ontario and McMaster Universities Arthritis Index pain subscale at screening and evaluated the safety, PK, and PD of three doses every two weeks (75-300 mg per dose) or six once-weekly M6495 s.c. doses (300 mg) or placebo (ratio 3:1) over 106 days' follow-up.

RESULTS

M6495 in single and multiple doses of less than or equal to 300 mg s.c. weekly was well tolerated with no clinically significant changes in any safety parameter. Adverse events more frequently reported in the M6495 groups were mostly mild cases of injection site reactions, myalgia, and nausea, which resolved after treatment cessation. The elimination half-life of single s.c. doses of M6495 ranged from 79 to 267 hours. M6495 administration substantially reduced serum ARGS levels, indicative of target engagement and indicating disease-modifying potential of M6495.

CONCLUSION

Treatment with M6495 in single and multiple doses up to and including 300 mg s.c. was found to be well tolerated and adequately safe for further clinical evaluation of potential disease-modifying effects.

Asia-Inclusive Global Development of Enpatoran: Results of an Ethno-Bridging Study, Intrinsic/Extrinsic Factor Assessments and Disease Trajectory Modeling to Inform Design of a Phase II Multiregional Clinical Trial

Enpatoran is a novel, highly selective, and potent dual toll-like receptor (TLR)7 and TLR8 inhibitor currently under development for the treatment of autoimmune disorders including systemic lupus erythematosus (SLE), cutaneous lupus erythematosus (CLE), and myositis. The ongoing phase II study (WILLOW; NCT05162586) is evaluating enpatoran for 24 weeks in patients with active SLE or CLE and is currently recruiting. To support development of WILLOW as an Asia-inclusive multiregional clinical trial (MRCT) according to International Conference on Harmonisation E5 and E17 principles, we have evaluated ethnic sensitivity to enpatoran based on clinical pharmacokinetic (PK), pharmacodynamic (PD), and safety data from an ethno-bridging study (NCT04880213), supplemented by relevant quantitative PK, PD, and disease trajectory modeling (DTM) results, and drug metabolism/disease knowledge. A single-center, open-label, sequential dose group study in White and Japanese subjects matched by body weight, height, and sex demonstrated comparable PK and PD properties for enpatoran in Asian vs. non-Asian (White and other) subjects across single 100, 200, and 300 mg orally administered doses. DTM suggested no significant differences in SLE disease trajectory for Asian vs. non-Asian individuals. Aldehyde oxidase (AOX) is considered to be a key contributor to enpatoran metabolism, and a literature review indicated no relevant ethnic differences in AOX function based on in vitro and clinical PK data from marketed drugs metabolized by AOX, supporting the conclusion of low ethnic sensitivity for enpatoran. Taken together, the inclusion of Asian patients in MRCTs including WILLOW was informed based on a Totality of Evidence approach.

Model-based meta-analysis using latent variable modeling to set benchmarks for new treatments of systemic lupus erythematosus

Several investigational agents are under evaluation in systemic lupus erythematosus (SLE) clinical trials but quantitative frameworks to enable comparison of their efficacy to reference benchmark treatments are lacking. To benchmark SLE treatment effects and identify clinically important covariates, we developed a model-based meta-analysis (MBMA) within a latent variable model framework for efficacy end points and SLE composite end point scores (BILAG-based Composite Lupus Assessment and Systemic Lupus Erythematosus Responder Index) using aggregate-level data on approved and investigational therapeutics. SLE trials were searched using PubMed and www.clinicaltrials.gov for treatment name, SLE and clinical trial as search criteria that resulted in four data structures: (1) study and investigational agent, (2) dose and regimen, (3) baseline descriptors, and (4) outcomes. The final dataset consisted of 25 studies and 81 treatment arms evaluating 16 different agents. A previously developed (K Goteti et al. 2022) SLE latent variable model of data from placebo arms (placebo + standard of care treatments) was used to describe aggregate SLE end points over time for the various SLE placebo and treatment arms in a Bayesian MBMA framework. Continuous dose-effect relationships using a maximum effect model were included for anifrolumab, belimumab, CC-220 (iberdomide), epratuzumab, lulizumab pegol, and sifalimumab, whereas the remaining treatments were modeled as discrete dose effects. The final MBMA model was then used to benchmark these compounds with respect to the maximal efficacy on the latent variable compared to the placebo. This MBMA illustrates the application of latent variable models in understanding the trajectories of composite end points in chronic diseases and should enable model-informed development of new investigational agents in SLE.

Model-Informed Selection of the Recommended Phase III Dose of the Inhibitor of Apoptosis Protein Inhibitor, Xevinapant, in Combination with Cisplatin and Concurrent Radiotherapy in Patients with Locally Advanced Squamous Cell Carcinoma of the Head and Neck

Xevinapant, an oral inhibitor of apoptosis protein (IAP) inhibitor, demonstrated efficacy in combination with chemoradiotherapy in a randomized phase II study (NCT02022098) in patients with locally advanced squamous cell carcinoma of the head and neck at 200 mg/day on days 1-14 of a 3-week cycle. To confirm 200 mg/day as the recommended phase III dose (RP3D), we integrated preclinical, clinical, pharmacokinetic/pharmacodynamic (PK/PD), and exposure-response modeling results. Population PK/PD modeling of IAP inhibition in peripheral blood mononuclear cells in 21 patients suggested the pharmacologically active dose range was 100-200 mg/day, with a trend for more robust inhibition at the end of the dosing interval at 200 mg/day based on an indirect response model. Additionally, the unbound average plasma concentration at 200 mg/day was similar to that associated with efficacy in preclinical xenograft models. Logistic regression exposure-response analyses of data from 62 patients in the phase II study showed exposure-related increases in probabilities of locoregional control at 18 months (primary end point), overall response, complete response, and the radiosensitization mechanism-related composite safety end point "mucositis and/or dysphagia" (P < 0.05). Exposure-response relationships were not discernible for 12 of 13 evaluated safety end points, incidence of dose reductions, and time to first dose reduction. Quantitative integration of all available data, including model-derived target inhibition profiles, positive exposure-efficacy relationships, and lack of discernible exposure-safety relationships for most safety end points, supports selection of xevinapant 200 mg/day on days 1-14 of a 3-week cycle as the RP3D, allowing for successive dose reductions to 150 and 100 mg/day to manage adverse events.

Opportunities and Challenges of Disease Progression Modeling in Drug Development - An IQ Perspective

Disease progression modeling (DPM) represents an important model-informed drug development framework. The scientific communities support the use of DPM to accelerate and increase efficiency in drug development. This article summarizes International Consortium for Innovation & Quality (IQ) in Pharmaceutical Development mediated survey conducted across multiple biopharmaceutical companies on challenges and opportunities for DPM. Additionally, this summary highlights the viewpoints of IQ from the 2021 workshop hosted by the US Food and Drug Administration (FDA). Sixteen pharmaceutical companies participated in the IQ survey with 36 main questions. The types of questions included single/multiple choice, dichotomous, rank questions, and open-ended or free text. The key results show that DPM has different representation, it encompasses natural disease history, placebo response, standard of care as background therapy, and can even be interpreted as pharmacokinetic/pharmacodynamic modeling. The most common reasons for not implementing DPM as frequently seem to be difficulties in internal cross-functional alignment, lack of knowledge of disease/data, and time constraints. If successfully implemented, DPM can have an impact on dose selection, reduction of sample size, trial read-out support, patient selection/stratification, and supportive evidence for regulatory interactions. The key success factors and key challenges of disease progression models were highlighted in the survey and about 24 case studies across different therapeutic areas were submitted from various survey sponsors. Although DPM is still evolving, its current impact is limited but promising. The success of such models in the future will depend on collaboration, advanced analytics, availability of and access to relevant and adequate-quality data, collaborative regulatory guidance, and published examples of impact.

Disease trajectory of SLE clinical endpoints and covariates affecting disease severity and probability of response: Analysis of pooled patient-level placebo (Standard-of-Care) data to enable model-informed drug development

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting multiple organ systems. Many investigational agents have failed or shown only modest effects when added to standard of care (SoC) therapy in placebo-controlled trials, and only two therapies have been approved for SLE in the last 60 years. Clinical trial outcomes have shown discordance in drug effects between clinical endpoints. Herein, we characterized longitudinal disease activity in the SLE population and the sources of variability by developing a latent disease trajectory model for SLE component endpoints (Systemic Lupus Erythematosus Disease Activity Index [SLEDAI], Physician's Global Assessment [PGA], British Isles Lupus Assessment Group Index [BILAG]) and composite endpoints (Systemic Lupus Erythematosus Responder Index [SRI], BILAG-based Composite Lupus Assessment [BICLA], and Lupus Low Disease Activity State [LLDAS]) using patient-level historical SoC data from nine phase II and III studies. Across all endpoints, in predictions up to 52 weeks from the final disease trajectory model, the following baseline covariates were associated with a greater decrease in SLE disease activity and higher response to placebo + SoC: Hispanic ethnicity from Central/South America, absence of hypocomplementemia, recent SLE diagnosis, and high baseline disease activity score using SLEDAI and BILAG separately. No discernible differences were observed in the trajectory of response to placebo + SoC across different SoC medications (antimalarial and immunosuppressant such as mycophenolate, methotrexate, and azathioprine). Across all endpoints, disease trajectory showed no difference in Asian versus non-Asian patients, supporting Asia-inclusive global SLE drug development. These results describe the first population approach to support a model-informed drug development framework in SLE.

Designing phase I oncology dose escalation using dose-exposure-toxicity models as a complementary approach to model-based dose-toxicity models

One of the objectives of oncology phase I dose-escalation studies has been to determine the maximum tolerated dose (MTD). Although MTD is no longer set as the dose for further development in contemporary oncology drug development, MTD determination is still important for informing the therapeutic index. Bayesian adaptive model-based designs are becoming mainstream in oncology first-in-human trials. Herein, we illustrate via simulations the use of systemic exposure in Bayesian adaptive dose-toxicity models to estimate MTD. We extend traditional dose-toxicity models to incorporate pharmacokinetic exposure, which provides information on exposure-toxicity relationships. We pursue dose escalation until the maximum tolerated exposure (corresponding to the MTD) is reached. By leveraging pharmacokinetics, dose escalation considers exposure and interindividual variability on a continuous rather than discrete domain, offering additional information for dose-escalation decisions. To demonstrate this, we generated 1000 simulations (starting dose of 1/25th the reference dose and six dose levels) for several different scenarios. Both rule-based and model-based designs were compared using metrics of potential safety, accuracy, and reliability. The mean results over simulations and different toxicity scenarios showed that model-based designs were better than rule-based methods and that exposure-toxicity model-based methods have the potential to valuably complement dose-toxicity model-based methods. Exposure-toxicity model-based methods had decreased underdose risk accompanied by a relatively smaller increase in overdose risk, resulting in improved net reliability. MTD estimation accuracy was compromised when exposure variability was large, emphasizing the importance of appropriate control of pharmacokinetic variability in phase I dose-escalation studies.

Exposure-response analyses for the MET inhibitor tepotinib including patients in the pivotal VISION trial: support for dosage recommendations

Purpose

Tepotinib is a highly selective MET inhibitor approved for treatment of non-small cell lung cancer (NSCLC) harboring METex14 skipping alterations. Analyses presented herein evaluated the relationship between tepotinib exposure, and efficacy and safety outcomes.

Methods

Exposure–efficacy analyses included data from an ongoing phase 2 study (VISION) investigating 500 mg/day tepotinib in NSCLC harboring METex14 skipping alterations. Efficacy endpoints included objective response, duration of response, and progression-free survival. Exposure–safety analyses included data from VISION, plus four completed studies in advanced solid tumors/hepatocellular carcinoma (30–1400 mg). Safety endpoints included edema, serum albumin, creatinine, amylase, lipase, alanine aminotransferase, aspartate aminotransferase, and QT interval corrected using Fridericia’s method (QTcF).

Results

Tepotinib exhibited flat exposure–efficacy relationships for all endpoints within the exposure range observed with 500 mg/day. Tepotinib also exhibited flat exposure–safety relationships for all endpoints within the exposure range observed with 30–1400 mg doses. Edema is the most frequently reported adverse event and the most frequent cause of tepotinib dose reductions and interruptions; however, the effect plateaued at low exposures. Concentration-QTc analyses using data from 30 to 1400 mg tepotinib resulted in the upper bounds of the 90% confidence interval being less than 10 ms for the mean exposures at the therapeutic (500 mg) and supratherapeutic (1000 mg) doses.

Conclusions

These analyses provide important quantitative pharmacologic support for benefit/risk assessment of the 500 mg/day dosage of tepotinib as being appropriate for the treatment of NSCLC harboring METex14 skipping alterations.

Registration Numbers

NCT01014936, NCT01832506, NCT01988493, NCT02115373, NCT02864992.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04441-3.

Abstract 5424: Selection of RP3D of xevinapant in combination with CRT in patients with LA SCCHN

Xevinapant, an antagonist of Inhibitor of Apoptosis Proteins (IAPs) showed significant improvement in locoregional control at 18 months (LRC18; primary endpoint), overall survival (OS) and progression-free survival (PFS) at an oral dose of 200 mg/day given on days 1-14 every 3 weeks in combination with CRT versus CRT with placebo in a phase II trial in patients with high-risk LA SCCHN (NCT02022098). In the dose escalation (DE) part of NCT02022098, 200 mg/day was the maximum tolerated dose and a trend of dose-response for efficacy in the 100-300 mg/day dose range was observed. The phase III TrilynX study of xevinapant plus CRT in patients with LA SCCHN is currently enrolling (NCT04459715). Here we present the integrated rationale for the recommended phase III dose (RP3D) of xevinapant 200 mg/day based on all available clinical and preclinical data and modeling and simulation (M&S).

At the RP3D, ~95% of the patients are projected to have free trough concentrations above in vitro IC50 for cIAP1 degradation (a pharmacodynamic [PD] marker), based on a population (pop) PK M&S. In patients, average free concentration over the dosing interval at RP3D is similar to that associated with maximal efficacy in preclinical SCCHN models. Pop PK/PD M&S

suggests that maximal cIAP1 degradation is maintained in PBMCs with 100-200 mg/day doses during the 14-day dosing period, with a trend of dose-response for the partial cIAP1 degradation at the end of the 3-week cycle.

Exposure response (E-R) analyses were conducted based on the pooled datasets of DE and randomized parts of study NCT02022098 (n=62 treated with xevinapant). Logistic regressions showed that probabilities of LRC18, overall response, complete response, and the composite safety endpoint of “mucositis and/or dysphagia” increase with increasing exposure (p&lt;0.05). Statistically significant E-R relationships were not discernible for any other evaluated safety endpoints or for PFS, OS, or duration of LRC. However, patients in higher exposure subgroups showed a longer duration of LRC.

In summary, integration of preclinical pharmacology, clinical efficacy and safety profiles, clinical PK/PD, popPK, and E-R analyses support the RP3D selection of xevinapant at 200 mg/day administered on days 1-14 every 3 weeks with concomitant CRT, allowing for successive dose reductions to 150 mg and 100 mg for management of toxicities.

Citation Format: Yulia Vugmeyster, Abhigyan Ravula, Elisabeth Rouits, Paul M. Diderichsen, Huub J. Kleijn, Kosalaram Goteti, Andreas Schroeder, Karthik Venkatakrishnan. Selection of RP3D of xevinapant in combination with CRT in patients with LA SCCHN [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5424.

Applying Modeling and Simulations for Rational Dose Selection of Novel Toll-Like Receptor 7/8 Inhibitor Enpatoran for Indications of High Medical Need

Dual toll‐like receptor (TLR) 7 and TLR8 inhibitor enpatoran is under investigation as a treatment for lupus and coronavirus disease 2019 (COVID‐19) pneumonia. Population pharmacokinetic/pharmacodynamic (PopPK/PD) model‐based simulations, using PK and PD (inhibition of ex vivo‐stimulated interleukin‐6 (IL‐6) and interferon‐α (IFN‐α) secretion) data from a phase I study of enpatoran in healthy participants, were leveraged to inform dose selection for lupus and repurposed for accelerated development in COVID‐19. A two‐compartment PK model was linked to sigmoidal maximum effect (E_max) models with proportional decrease from baseline characterizing the PD responses across the investigated single and multiple doses, up to 200 mg daily for 14 days (n = 72). Concentrations that maintain 50/60/90% inhibition (IC_50/60/90) of cytokine secretion (IL‐6/IFN‐α) over 24 hours were estimated and stochastic simulations performed to assess target coverage under different dosing regimens. Simulations suggested investigating 25, 50, and 100 mg enpatoran twice daily (b.i.d.) to explore the anticipated therapeutic dose range for lupus. With 25 mg b.i.d., > 50% of subjects are expected to achieve 60% inhibition of IL‐6. With 100 mg b.i.d., most subjects are expected to maintain almost complete target coverage for 24 hours (> 80% subjects IC_90,IL‐6 = 15.5 ng/mL; > 60% subjects IC_90,IFN‐α = 22.1 ng/mL). For COVID‐19, 50 and 100 mg enpatoran b.i.d. were recommended; 50 mg b.i.d. provides shorter IFN‐α inhibition (median time above IC₉₀ = 13 hours/day), which may be beneficial to avoid interference with the antiviral immune response. Utilization of PopPK/PD models initially developed for lupus enabled informed dose selection for the accelerated development of enpatoran in COVID‐19.

Optimization of dose selection using multiple surrogates of toxicity as a continuous variable in phase I cancer trial

In phase I trials, it is the top priority of clinicians to effectively treat patients and minimize the chance of exposing them to subtherapeutic and overly toxic doses, while exploiting patient information. Motived by this practical consideration, we revive the one parameter linear dose-finder developed in 1970s to accommodate a continuous toxicity response in the phase I cancer clinical trials, which is called the two parameters linear dose-finder (2PLD). The 2PLD is a fully Bayesian model that assumes a linear relationship between toxicity response and dose. We suggest a dose search algorithm based on the 2PLD to exploit the grades of toxicities from multiple adverse events to align with Common Toxicity Criteria for Adverse Events provided by the National Cancer Institute. The proposed search procedure suggests an optimal dose to each patient by using accrued patients' information while controlling the posterior probability of overdose. The heterogeneity of patients in dose reaction is addressed by making a fully Bayesian inference about the standard deviation of toxicity responses. The 2PLD can be an attractive tool for clinical scientists due to its parsimonious description of a toxicity-dose curve and medical interpretation as well as an automatic posterior computation. We illustrate the performance of this design using simulation data to identify the maximum tolerated dose.

518. Model-informed Dose Selection of Dual Toll-like Receptor 7/8 Inhibitor Enpatoran (M5049) for the Treatment of COVID-19 Pneumonia

Background

Enpatoran, formerly known as M5049, is a potential first-in-class small molecule antagonist of toll-like receptors (TLR) 7 and 8, which may prevent viral-associated hyperinflammatory response and progression to ‘cytokine storm’ in coronavirus disease 2019 (COVID-19) patients. The objective of this study was to leverage existing population pharmacokinetic/pharmacodynamic (popPK/PD) models for enpatoran to inform dose selection for an accelerated Phase II study in COVID-19 patients with pneumonia.

Methods

The popPK/PD models were based on plasma PK and PD biomarker (ex vivo-stimulated interleukin [IL]6 and interferon α [IFNα] secretion) data from the enpatoran first-in-human Phase I study in healthy participants (Port A, et al. Lupus Sci Med 2020;7(Suppl. 1): Abstract P135). A two-compartment model describing PK used a sigmoidal E_max model with proportional decrease from baseline characterizing the PD response across the investigated single and multiple daily dose range of 1–200 mg (N=72). Concentrations that inhibited 50% and 90% (IC₅₀/IC₉₀) of cytokine secretion were estimated and stochastic simulations were performed to assess target coverage under different dosing regimens.

Results

Simulations suggested that, to achieve maximal inhibition of IL-6 over time, enpatoran PK concentrations would be maintained above the IC₉₀ throughout the dosing interval with doses of 100 mg and 50 mg twice daily in 90% and 30% of participants, respectively. In comparison, IFNα inhibition was predicted to be lower, with IC₉₀ coverage in 60% and 8% of participants with twice daily doses of 100 mg and 50 mg enpatoran, respectively.

Conclusion

Utilization of existing popPK/PD models allowed for the accelerated development of enpatoran in COVID-19 to address an unprecedented global pandemic. Rational model-informed dose selection was supported by data from a Phase I study in which there were no safety concerns.

Disclosures

Lena Klopp-Schulze, PhD, Merck KGaA, Darmstadt, Germany (Employee) Jamie Shaw, BS, EMD Serono Research & Development Institute, Inc., Billerica, MA, USA (an affiliate of Merck KGaA, Darmstadt, Germany) (Employee) Jennifer Dong, PhD, EMD Serono Research & Development Institute, Inc., Billerica, MA, USA (an affiliate of Merck KGaA, Darmstadt, Germany) (Employee) Akash Khandelwal, PhD, Merck KGaA, Darmstadt, Germany (Employee, Shareholder) Elizabeth Adams, MD, BioNTech SE, Germany (Employee)EMD Serono Research & Development Institute, Inc., Billerica, MA, USA (an affiliate of Merck KGaA, Darmstadt, Germany)(employer at the time of study) (Employee) Dongzi Yu, MD, EMD Serono Research & Development Institute, Inc., Billerica, MA, USA (an affiliate of Merck KGaA, Darmstadt, Germany) (Employee) Kosalaram Goteti, PhD, EMD Serono Research & Development Institute, Inc., Billerica, MA, USA (an affiliate of Merck KGaA, Darmstadt, Germany) (Employee)Pfizer (Shareholder)

To blind or not to blind first in human and exploratory clinical trials: Acceleration of development vs. risk of bias

An IQ consortium working group (WG) conducted a survey across multiple biopharmaceutical companies to gain information about the level of blinding commonly utilized for early clinical development trials. The main objectives were: (1) to understand blinding practices between healthy volunteer (HV) and early explorative patient trials in all therapeutic areas except oncology where early clinical trials are commonly open‐label; (2) to understand the rationale for blinding/unblinding practices; (3) to understand the groups and personnel involved in unblinding; and (4) strategic considerations around blinding/unblinding options in early clinical development trials—risk of bias vs. potential for acceleration. A survey containing 31 main questions with additional sub‐clarifying questions was conducted. Sixteen large and mid‐size pharmaceutical companies responded. Responses were aligned across functions within each participating company. Additional information was gathered at an American Association of Pharmaceutical Scientists (AAPS) webinar with polling options to roughly 550 registered attendees to evaluate the reason for the unblinding decisions. The results revealed divergence across companies in the blinding approaches most commonly applied but with some study types, there were clearly favored options. Based on these results, the WG developed strategic considerations for first‐in‐human HV trials and nonpivotal explorative trials in patients. This paper should facilitate discussions among various clinical development functions, such as Clinical Pharmacology, Statistics, Clinical, Bioanalytics, and Regulatory Functions. Such discussions on study design and operations are warranted to allow implementation of more flexible blinding approaches to accelerate data driven decisions in drug development and allow earlier access of patients to needful medicines.

Phase 1 study in healthy participants of the safety, pharmacokinetics, and pharmacodynamics of enpatoran (M5049), a dual antagonist of toll-like receptors 7 and 8

This study evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of single and multiple oral doses of enpatoran (formerly named M5049), a new toll-like receptor (TLR) 7 and 8 dual antagonist, and the effect of food on a single dose in healthy participants. In this single phase 1, randomized (3:1), double-blind, placebo-controlled study, 96 participants received single and multiple ascending oral doses of enpatoran. Participants in single-dose cohorts received one dose of enpatoran (1, 3, 9, 25, 50, 100, or 200 mg) or placebo using a sentinel dosing strategy. Multiple-dose cohorts received enpatoran (9, 25, or 200 mg once daily, or 25 or 50 mg twice daily) or placebo for 14 days. Safety, tolerability, PK, and PD (ex vivo-stimulated cytokine secretion) were assessed in both parts. The effect of food was assessed in an open-label, one-way crossover study in the 25 mg single-dose cohort. Single- and multiple-oral doses of enpatoran up to 200 mg were well tolerated and no significant dose-limiting adverse events or safety signals were observed under fasting or fed conditions. PK parameters were linear and dose-proportional across the dose range evaluated, with a slightly delayed absorption and lower peak concentration observed at 25 mg with food. Exposure-dependent inhibition of ex vivo-stimulated interleukin-6 secretion was observed, with maximum inhibition at 200 mg. Enpatoran was well tolerated at doses up to 200 mg. Further investigation of enpatoran is warranted as a potential treatment for diseases driven by TLR7/8 overactivation, such as systemic lupus erythematosus and COVID-19 pneumonia.

Comparison of Various Phase I Combination Therapy Designs in Oncology for Evaluation of Early Tumor Shrinkage Using Simulations

There is still a lack of efficient designs for identifying the dose response in oncology combination therapies in early clinical trials. The concentration response relationship can be identified using the early tumor shrinkage time course, which has been shown to be a good early response marker of clinical efficacy. The performance of various designs using an exposure–tumor growth inhibition model was explored using simulations. Different combination effects of new drug M and cetuximab (reference therapy) were explored first assuming no effect of M on cetuximab (to investigate the type I error (α)), and subsequently assuming additivity or synergy between cetuximab and M. One‐arm, two‐arm, and four‐arm designs were evaluated. In the one‐arm design, 60 patients received cetuximab + M. In the two‐arm design, 30 patients received cetuximab and 30 received cetuximab + M. In the four‐arm design, in addition to cetuximab and cetuximab + M as standard doses, combination arms with lower doses of cetuximab were evaluated (15 patients/arm). Model‐based predictions or “simulated observations” of early tumor shrinkage at week 8 (ETS8) were compared between the different arms. With the same number of individuals, the one‐arm design showed better statistical power than other designs but led to strong inflation of α in case of misestimated reference for ETS8 value. The two‐arm design protected against this misestimation and, with the same total number of subjects, would provide higher statistical power than a four‐arm design. However, a four‐arm design would be helpful for exploring more doses of cetuximab in combination with M to better understand the interaction.

First-in-human, randomized dose-escalation study of the safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of PF-06480605 in healthy subjects

AIMS

Human genetic, tissue expression, proteomics, transcriptomics and nonclinical studies implicate tumour necrosis factor α-like ligand 1A (TL1A) as a novel target in inflammatory bowel disease (IBD). PF-06480605, a fully human immunoglobulin G1 monoclonal antibody, targets TL1A. This first-in-human, Phase 1, dose-escalation study assessed safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of intravenous (IV) and subcutaneous (SC) PF-06480605 in healthy subjects (NCT01989143).

METHODS

Ninety-two subjects were randomized to single ascending doses (SAD), PF-06480605 1 mg, 3 mg, 10 mg, 30 mg, 100 mg, 300 mg, 600 mg or 800 mg IV, or multiple ascending doses (MAD), PF-06480605 3 × 500 mg IV, or 3 × 30 mg, 3 × 100 mg, or 3 × 300 mg SC every 2 weeks for three doses, or placebo. Safety, tolerability, pharmacokinetics, immunogenicity profiles and total TL1A, anti-drug antibody (ADA) and neutralizing antibody (NAb) levels were assessed at pre-determined times.

RESULTS

PF-06480605 SAD up to 800 mg IV and MAD up to 300 mg ×3 SC and 500 mg ×3 IV were well tolerated. Overall, there were 45 and 44 treatment-emergent adverse events in SAD and MAD cohorts, respectively, and no deaths or serious adverse events. PF-06480605 exposure generally increased dose-dependently. ADA and NAb levels did not impact safety, pharmacokinetics, or pharmacodynamics at higher doses. Target engagement was demonstrated through dose-dependent differences in serum total soluble TL1A concentrations for PF-06480605 vs placebo cohorts.

CONCLUSIONS

PF-06480605 was generally well tolerated, and binding of soluble TL1A was maintained throughout the dose interval, supporting further study of PF-06480605 in patients with IBD and other inflammatory conditions.

Effect of PF-04634817, an Oral CCR2/5 Chemokine Receptor Antagonist, on Albuminuria in Adults with Overt Diabetic Nephropathy

Introduction

Inflammatory cell recruitment, which is potentially mediated by the monocyte chemoattractant protein 1/C-C chemokine receptor type 2 (CCR2) system and by C-C chemokine receptor type 5 (CCR5) activity, may play a role in the development and progression of diabetic nephropathy. PF-04634817 is a dual chemokine CCR2/5 receptor antagonist that is being developed for the treatment of diabetic nephropathy.

Methods

We evaluated the efficacy of PF-04634817 compared with matching placebo for reduction of albuminuria after 12 weeks of treatment in subjects with type 2 diabetes who received standard of care (SOC; angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy), in a randomized, double-blind, placebo-controlled, parallel-group phase 2 study.

Results

A total of 226 subjects who received SOC with baseline estimated glomerular filtration rates between 20 and 75 ml/min per 1.73 m² and a baseline urinary albumin-to-creatinine ratio (UACR) of ≥300 mg/g were randomly assigned 3:1 to receive PF-04634817 (150 or 200 mg orally, once daily) or placebo. The primary analysis was Bayesian, with an informative prior for placebo response (equivalent to including an additional 80 subjects in the placebo arm). We observed a placebo-adjusted reduction in UACR of 8.2% (ratio 0.918; 95% credible interval: 0.75–1.09) at week 12 in the PF-04634817 arm. PF-04634817 appeared to be safe and well-tolerated.

Conclusion

Despite the good safety profile shown by PF-04634817, clinical development for this indication was discontinued in light of the modest efficacy observed.

Evaluation of a Janus kinase 1 inhibitor, PF-04965842, in healthy subjects: A phase 1, randomized, placebo-controlled, dose-escalation study

AIMS

To determine the safety, tolerability, pharmacokinetics and pharmacodynamics of the Janus kinase 1-selective inhibitor, PF-04965842.

METHODS

This was a phase 1, first-in-human, randomized, double-blind, placebo-controlled, combination single- and multiple-dose escalation, parallel design study in healthy subjects (http://clinicaltrials.gov, NCT01835197). Subjects received a single dose of placebo or 3, 10, 30, 100, 200, 400 or 800 mg PF-04965842 (single ascending dose phase) and placebo or 30 mg once daily (QD), 100 mg QD, 200 mg QD, 400 mg QD, 100 mg twice daily (BID) or 200 mg BID PF-04965842 for 10 consecutive days (multiple ascending dose phase). The primary objective was to determine the safety and tolerability of PF-04965842.

RESULTS

Seventy-nine subjects were randomized and received study treatments. There were no deaths or serious adverse events. The most frequent treatment-emergent adverse events were headache (n = 13), diarrhoea (n = 11) and nausea (n = 11). PF-04965842 was absorbed rapidly (median time at which maximum plasma concentration occurred generally ≤1 h following either single- or multiple-dose administration) and eliminated rapidly (mean t_½ 2.8-5.2 h after 10 days of QD or BID administration in the multiple ascending dose phase). Increases in maximum plasma concentration and area under the concentration-time curve were dose proportional up to 200 mg (single or total daily doses) with an apparent trend towards greater than proportional increases with higher doses. Less than 4.4% of the dose was recovered unchanged in urine. Changes in pharmacodynamic biomarkers were consistent with the known effects of Janus kinase signalling inhibition.

CONCLUSIONS

These results support further evaluation of PF-04965842 for clinical use in patients with inflammatory diseases.

The Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of a TYK2/JAK1 Inhibitor (PF-06700841) in Healthy Subjects and Patients With Plaque Psoriasis

The safety, tolerability, pharmacokinetics, and pharmacodynamics of PF-06700841 were assessed in a randomized, double-blind, placebo-controlled, single- and multiple-dose escalation, parallel-group study in healthy subjects and patients with plaque psoriasis. The single ascending dose (1, 3, 10, 30, 100, or 200 mg) and multiple ascending dose (MAD; PF-06700841; up to 175 mg once daily or 50 mg twice daily for 10 days) periods included 54 healthy participants. In addition, 30 patients with psoriasis received PF-06700841 30 or 100 mg or placebo once daily for 28 days. Single PF-06700841 doses were rapidly absorbed, with peak plasma concentrations ≤ 1 hour, proportional exposure up to 100 mg, and mean half-life 3.8-7.5 hours. On day 10 of MAD, plasma concentrations peaked at ≤1.5 hours postdose (10-175 mg once daily). Elimination half-life was 4.9-10.7 hours; steady state was reached by day 8. In psoriasis patients on day 28, peak plasma concentrations occurred at 1-2 hours. Biomarkers IP-10 and high-sensitivity C-reactive protein were reduced and returned to near baseline levels after dosing. Maximal mean percent change from baseline in the Psoriasis Area and Severity Index scores for PF-06700841 30 mg once daily and 100 mg once daily were -67.92% and -96.31%, respectively, in week 4. All adverse events were mild/moderate. PF-06700841 was safe and well tolerated up to 200 mg once daily in healthy subjects and 100 mg once daily in patients with psoriasis, suggesting potential therapeutic utility in plaque psoriasis and other inflammatory diseases.

Prediction of drug clearance in children: an evaluation of the predictive performance of several models

The objective of this study is to evaluate the predictive performance of several models to predict drug clearance in children ≤5 years of age. Six models (allometric model (data-dependent exponent), fixed exponent of 0.75 model, maturation model, body weight-dependent model, segmented allometric model, and age-dependent exponent model) were evaluated in this study. From the literature, the clearance values for six drugs from neonates to adults were obtained. External data were used to evaluate the predictive performance of these models in children ≤5 years of age. With the exception of a fixed exponent of 0.75, the mean predicted clearance in most of the age groups was within ≤50% prediction error. Individual clearance prediction was erratic by all models and cannot be used reliably to predict individual clearance. Maturation, body weight-dependent, and segmented allometric models to predict clearances of drugs in children ≤5 years of age are of limited practical value during drug development due to the lack of availability of data. Age-dependent exponent model can be used for the selection of first-in-children dose during drug development.

Prediction of drug concentration-time data in humans from animals: a comparison of three methods

The main objective of this work is to evaluate three methods to predict concentration-time data of drugs in humans in a multi-compartment system using animal pharmacokinetic parameters following intravenous administration. The prediction of concentration-time data in humans in a multi-compartment system was based on two proposed methods of Mordenti. The third method was based on the assumption that all drugs follow a single-compartment system. Ten drugs from the literature were chosen that were described by two-compartment model in both human and animals. Two-compartment model parameters (CL, V(c), V(ss), V(β), α, A, β and B) of at least 3 animals were scaled to humans and then were used to predict plasma concentrations-time data in humans. Allometrically scaled pharmacokinetic parameters from animals were also used to predict human profile using one-compartment model as a comparison. The results indicated that in a multi-compartment system, application of pharmacokinetic constants provided better prediction of concentration-time data in humans than the assumption that all drugs follow a single-compartment model. Both the proposed methods of Mordenti provided almost similar concentration-time profiles for most of the drugs. For some drugs, predicted α values were substantially higher than the observed values. This prediction error in α resulted in under-prediction of drug concentrations in distribution phase. In order to reduce the prediction error in α, Waijma's method for the prediction of α was modified which resulted in an improved prediction of concentration-time data in humans. Overall, Mordenti's proposed 2 methods and where necessary by modifying Waijma's method for the prediction of α can be used for reasonably accurate prediction of concentration-time data of drugs in humans.

Preclinical pharmacokinetic/pharmacodynamic models to predict synergistic effects of co-administered anti-cancer agents

PURPOSE

Pharmacokinetic/pharmacodynamic (PK/PD) models have been shown to be useful in predicting tumor growth rates in mouse xenografts. We applied novel PK/PD models to the published anticancer combination therapies of tumor growth inhibition to simulate synergistic changes in tumor growth rates. The parameters from the PK/PD model were further used to estimate clinical doses of the combination.

METHODS

A PK/PD model was built that linked the dosing regimen of a compound to the inhibition of tumor growth in mouse xenograft models. Two subsequent PK/PD models were developed to simulate the published tumor growth profiles of combination treatments. Model I predicts the tumor growth curve assuming that the effect of two anticancer drugs, AZD7762 and irinotecan, is synergistic when given in combination. Model II predicts the tumor growth curve assuming that the effect of co-administering flavopiridol and irinotecan is maximally synergistic when dosed at an optimal interval.

RESULTS

Model I was able to account for the synergistic effects of AZD7762 following the administration of irinotecan. When Model II was applied to the antitumor activity of irinotecan and flavopiridol combination therapy, the modeling was able to reproduce the optimal dosing interval between administrations of the compounds. Furthermore, Model II was able to estimate the biologically active dose of flavopiridol recommended for phase II studies.

CONCLUSIONS

The timing of clinical combination therapy doses is often selected empirically. PK/PD models provide a theoretical structure useful in the design of the optimal clinical dose, frequency of administration and the optimal timing of administration between anticancer agents to maximize tumor suppression.

Efficacy of local dipyridamole therapy in a porcine model of arteriovenous graft stenosis

Perivascular delivery of antiproliferative drugs has been proposed as an approach to prevent neointimal hyperplasia associated with hemodialysis polytetrafluoroethylene (PTFE) grafts. We examined this approach to deliver dipyridamole in a porcine graft model. PTFE grafts were implanted between the carotid artery and external jugular vein bilaterally in pigs. During the surgery or 1 week post-graft placement, dipyridamole (0.26-52 mg) alone or incorporated in microspheres was mixed with an injectable polymeric gel and applied to the graft-arterial and graft-venous anastomoses on one side, whereas the contralateral control graft received no treatment. Three or four weeks after operation, the grafts and adjacent vessels were explanted en bloc and cross-sections of the anastomoses were examined histologically. The degree of neointimal hyperplasia was quantified by planimetry. In separate experiments, dipyridamole was extracted from the explanted tissues and assayed by spectrofluorometry. The normalized median hyperplasia areas of the treated and control graft-venous anastomoses were 0.45 (25th-75th percentile, 0.30-0.86) and 0.24 (0.21-0.30), respectively (N=7; P=0.08). The median hyperplasia areas of the treated and control graft-arterial anastomoses were 0.12 (0.07-0.39) and 0.11 (0.09-0.13), respectively (N=7; P=0.31). The dipyridamole levels in the vascular walls around the anastomoses were at or above the in vitro inhibitory concentrations for approximately 3 weeks. These results suggest that the local perivascular sustained delivery of dipyridamole, even at high dosages, was ineffective in inhibiting neointimal hyperplasia associated with PTFE grafts in a porcine model.

Perivascular Tissue Pharmacokinetics of Dipyridamole

PURPOSE

The tissue diffusivity (D(g)) and partitioning (K) for dipyridamole were determined and a model was developed to examine the relationship between perivascular dose and local dipyridamole tissue concentrations.

METHODS

Experiments were performed using an in vitro perfusion apparatus that recirculated buffer through different graft samples or normal porcine femoral arteries and veins. The grafts or blood vessels were immersed in a compartment containing Krebs-Henseleit (KH) buffer and dipyridamole (30 microg/mL). The recirculating buffer was sampled at multiple time points and dipyridamole was assayed. Estimates of the effective diffusivity (D(g)) and partition coefficient (K) of the drug in the vessel wall were determined and used to simulate dipyridamole tissue concentration after perivascular delivery.

RESULTS

Dipyridamole diffusivity within native femoral veins (D(g) = 3.87 +/- 0.93 x 10(-6) cm2/s) was approximately twice that within femoral arteries (D(g) = 2.06 +/- 0.79 x 10(-6) cm2/s, p < 0.01). Explanted grafts showed the lowest diffusivity. Partition coefficients of femoral arteries (K = 4.11 +/- 0.99) were higher than those of femoral veins (K = 2.05 +/- 0.85, p < 0.01) and explanted graft (K = 0.89 +/- 0.56, p < 0.01).

DISCUSSION

The results demonstrate that local drug kinetics vary greatly for different types of blood vessels and grafts. The pharmacokinetic parameters and resulting computational simulations are helpful in exploring perivascular drug delivery strategies.