A Randomized, Double-Blind, Parallel Controlled, Single-Dose Phase I Study Comparing the Pharmacokinetics, Safety, and Immunogenicity of the Infliximab Biosimilar CMAB008 and the Reference Product in Healthy Chinese Male Subjects

A rare case report: Myopathy related to the interaction between azathioprine and infliximab in the treatment of ulcerative colitis and ankylosing spondylitis

Key Clinical Message

Administering azathioprine or infliximab for UC and AS treatment carries a significant risk of adverse reactions. Here, we present the case diagnosed with UC and AS, who received treatment with azathioprine and infliximab for 10 months, and subsequently developed drug-induced myopathy affecting the right vastus medialis muscle.

Abstract

Drug-induced myopathy is an uncommon form of muscle injury that can arise in patients without preexisting muscle conditions when exposed to therapeutic doses of certain medications. Administering azathioprine or infliximab for ulcerative colitis (UC) and ankylosing spondylitis (AS) treatment carries a significant risk of adverse reactions, including drug-induced myopathy and increased susceptibility to opportunistic infections. However, occurrences of myopathy induced by the combination of azathioprine and infliximab are rarely reported in clinical practice. Here, we present the case of a 37-year-old male patient diagnosed with UC and AS, who received treatment with azathioprine and infliximab for 10 months. Despite the resolution of symptoms and improvement in intestinal mucosal inflammation observed via endoscopy, the patient subsequently developed drug-induced myopathy affecting the right vastus medialis muscle.

Population Pharmacokinetics of CMAB008 (an Infliximab Biosimilar) and Remicade® in Healthy Subjects and Patients with Moderately to Severely Active Rheumatoid Arthritis

INTRODUCTION

CMAB008 is a monoclonal antibody developed as a biosimilar to infliximab (Remicade^®, Janssen). The pharmacokinetic characteristics of CMAB008 and Remicade^® in healthy subjects and patients with moderately to severely active rheumatoid arthritis (RA) were investigated using a population modeling approach, and the pharmacokinetic similarity of CMAB008 to Remicade^® was assessed.

METHODS

The population pharmacokinetic model was developed on the basis of intensive pharmacokinetic data from a phase 1 study in healthy male subjects and combined intensive and sparse pharmacokinetic data from a phase 3 study in patients with RA.

RESULTS

A two-compartment model with first-order elimination adequately described CMAB008 and Remicade^® concentration data in healthy subjects and patients with RA. The analysis of covariates identified anti-drug antibody (ADA), neutralizing antibody (NAB), real-time body weight (BWT), and real-time albumin (ALB) as significant covariates on clearance, and BWT was also a significant covariate for the central volume of distribution. The treatment type (CMAB008 versus Remicade^®) and the study population (healthy subjects versus patients with RA) were not identified as significant covariates on the pharmacokinetics of infliximab, demonstrating pharmacokinetic similarity between CMAB008 and Remicade^® in both study populations. The effect of BWT and ALB changes on exposures to infliximab was within the acceptable range, suggesting that the 3 mg/kg regimen is appropriate in clinical practice for patients with RA and BTW and ALB distribution within the range evaluated in the current analysis.

CONCLUSIONS

The pharmacokinetic characteristics were similar between CMAB008 and Remicade^® in healthy subjects and patients with RA. CMAB008 can be considered bioequivalent to Remicade^®.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers NCT04779892, NCT03478111.