Impact of immunogenicity on clinical efficacy and toxicity profile of biologic agents used for treatment of inflammatory arthritis in children compared to adults

The Impact of Immunogenicity on the Pharmacokinetics, Efficacy, and Safety of Sotatercept in a Phase III Study of Pulmonary Arterial Hypertension

Sotatercept, a soluble fusion protein comprising the extracellular domain of activin receptor type IIA linked to the Fc portion of human IgG1, is a first-in-class activin signaling inhibitor under development for the treatment of pulmonary arterial hypertension (PAH). We evaluated antidrug antibody (ADA) development and determined the effects of immunogenicity on the pharmacokinetics (PKs), efficacy, and safety of sotatercept in STELLAR, a multicenter, double-blind phase III trial (NCT04576988) wherein participants with PAH were randomized 1:1 to receive sotatercept (starting dose 0.3; target dose 0.7 mg/kg) or placebo subcutaneously every 3 weeks in combination with background therapies for ≤ 72 weeks. ADA-positive (ADA-POS) participants were identified and characterized for neutralizing antibodies (NAbs). PKs, efficacy, and safety were evaluated by ADA and NAb status. Of 162 evaluable participants, 42 (25.9%) were ADA-POS through week 24, of whom 11 (6.8%) were also NAb-POS. Median onset of ADAs was 3.29 weeks (interquartile range (IQR): 3.14-6.14), and median duration was 6 weeks (IQR: 3.14-17.86). No clinically meaningful differences were found across subgroups that were ADA-NEG, ADA-POS/NAb-NEG, and ADA-POS/NAb-POS, in terms of PKs (sotatercept trough concentration over time, mean postdose trough concentration at the end of treatment, and clearance), efficacy (changes from baseline in 6-minute walk distance, pulmonary vascular resistance, and N-terminal pro-B-type natriuretic peptide levels), and safety (incidence of hypersensitivity, anaphylactic reactions, and administration site reactions). We conclude that ADA incidence from sotatercept treatment was 25.9% and did not meaningfully affect the PKs, efficacy, or safety of sotatercept in participants with PAH.

Streamlining biosimilar development based on 20 years' experience

INTRODUCTION

Biosimilar clinical programs could be streamlined by prudent application of improved methodologies and knowledge accumulated over the past 20 years. This review focuses on whether complex comparative efficacy trials are routinely needed and how to achieve a more tailored approach to biosimilar development.

AREAS COVERED

Key learnings over the past 20 years are summarized. It is noted that a one size fits all approach to biosimilar development is not appropriate: biological medicines fall within a wide spectrum of complexity, with blurring at the interface between biological products and small molecules. The interrelationship between quality, potency, pharmacokinetics, pharmacology, immunogenicity, efficacy, and safety are reviewed. Current regulatory thinking is reviewed with a look into what future challenges lie ahead.

EXPERT OPINION

To tailor regulatory requirements for marketing approval of biosimilars, it is proposed that a biosimilarity report be introduced. This report would integrate quality, pharmacology, immunogenicity, efficacy and safety findings and address how the clinical program could be tailored based on the totality of evidence.

Untoward immune effects of modern medication

Immune-related adverse events (irAEs) represent an increasingly concerning challenge in the assessment of biopharmaceutical products. In contrast to historically rare allergic reactions associated with small chemical drugs, contemporary biotherapeutics exhibit a significantly higher morbidity of irAEs, because of their complex structure and comprehensive mechanisms of action. While the immunogenicity of protein-based compounds is associated with the induction of anti-drug antibodies, the pathogenesis of irAEs in advanced biologics, such as cell and gene therapy, remains to be further delineated. In the current study, I present an updated profile regarding the untoward immune effects of medications, covering various material categories systematically, with the underlying mechanisms to inspire risk mitigation in biopharmaceutical development and application.

Tailored therapeutic decision of rheumatoid arthritis using proteomic strategies: how to start and when to stop?

Unpredictable treatment responses have been an obstacle for the successful management of rheumatoid arthritis. Although numerous serum proteins have been proposed, there is a lack of integrative survey to compare their relevance in predicting treatment outcomes in rheumatoid arthritis. Also, little is known about their applications in various treatment stages, such as dose modification, drug switching or withdrawal. Here we present an in-depth exploration of the potential usefulness of serum proteins in clinical decision-making and unveil the spectrum of immunopathology underlying responders to different drugs. Patients with robust autoimmunity and inflammation are more responsive to biological treatments and prone to relapse during treatment de-escalation. Moreover, the concentration changes of serum proteins at the beginning of the treatments possibly assist early recognition of treatment responders. With a better understanding of the relationship between the serum proteome and treatment responses, personalized medicine in rheumatoid arthritis will be more achievable in the near future.

Proposal of International Council for Harmonization (ICH) Guideline for the Approval of Biosimilars

OBJECTIVES

Since the initial release of biosimilars 18 years ago, regulations for their licensing have changed considerably; however, there is no global consensus on these regulations. Establishing harmonized regulatory guidelines for the approval of biosimilars with support from the ICH, an independent, non-profit association under Swiss law, will significantly enhance the affordability of biological drugs.

METHODS

Regulatory guidelines from the Food and Drug Administration (FDA), European Medicines Agency (EMA), Medicines and Healthcare products Regulatory Agency (MHRA), and World Health Organization (WHO) were analyzed for historical changes and elements critical to the safety and efficacy of biosimilars.

RESULTS

Analysis of all EMA and FDA filings show that none of the animal testing and clinical efficacy testing failed because animals do not have the required receptors to initiate pharmacologic responses, and efficacy studies cannot be statistically powered to conclude any results. New analytical technologies will enable good biosimilarity determination, avoiding both tests.

CONCLUSION

Scientifically based ICH guidelines that remove redundant studies will reduce development costs, improve safety, and allow global drug distribution based on single compliance. These guidelines are particularly necessary for emerging countries lacking the expertise and resources to evaluate biosimilar filings.

Pediatric uveitis: Role of the pediatrician

The challenges of childhood uveitis lie in the varied spectrum of its clinical presentation, the often asymptomatic nature of disease, and the evolving nature of the phenotype alongside normal physiological development. These issues can lead to delayed diagnosis which can cause significant morbidity and severe visual impairment. The most common ocular complications include cataracts, band keratopathy, glaucoma, and macular oedema, and the various associated systemic disorders can also result in extra-ophthalmic morbidity. Pediatricians have an important role to play. Their awareness of the various presentations and etiologies of uveitis in children afford the opportunity of prompt diagnosis before complications arise. Juvenile Idiopathic Arthritis (JIA) is one of the most common associated disorders seen in childhood uveitis, but there is a need to recognize other causes. In this review, different causes of uveitis are explored, including infections, autoimmune and autoinflammatory disease. As treatment is often informed by etiology, pediatricians can ensure early ophthalmological referral for children with inflammatory disease at risk of uveitis and can support management decisions for children with uveitis and possible underling multi-system inflammatory disease, thus reducing the risk of the development of irreversible sequelae.