Phase 3 Study of Subcutaneous Versus Intravenous Ravulizumab in Eculizumab-Experienced Adult Patients with PNH: Primary Analysis and 1-Year Follow-Up

Consensus recommendations for optimising the diagnosis and treatment of paroxysmal nocturnal haemoglobinuria in Singapore

Introduction

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare haematologic disease characterised by intravascular haemolysis, thrombophilia and bone marrow failure. There is a lack of established clinical guidance on the screening, diagnosis and manage-ment of PNH in Singapore. A relatively low level of awareness among healthcare professionals regarding PNH manifestations further contributes to diagnostic delays. Additionally, limited access to complement inhibitors, like eculizumab, may delay treatment and impact patient outcomes.

Method

Nine haematologists from different institu-tions in Singapore convened to formulate evidence-based consensus recommendations for optimising the diagnosis and management of patients with PNH and improving access to novel treatments. The experts reviewed the existing literature and international guidelines published from January 2010 to July 2023, focusing on 7 clinical questions spanning PNH screening, diagnostic criteria, investigations, treatment and monitoring of subclinical and classic disease, PNH with underlying bone marrow disorders, and PNH in pregnancy. A total of 181 papers were reviewed to formulate the statements. All experts voted on the statements via 2 rounds of Delphi and convened for an expert panel discussion to finetune the recommendations.

Results

Sixteen statements have been formulated for optimising the screening, diagnosis and management of PNH. Upon confirmation of PNH diagnosis, individuals with active haemolysis and/or thrombosis should be considered for anti-complement therapy, with eculizumab being the only approved drug in Singapore.

Conclusion

The current recommendations aim to guide the clinicians in optimising the screening, diagnosis and management of PNH in Singapore.

Evaluating unmet needs in large-volume subcutaneous drug delivery: U.S. payer perspectives on a novel, large-volume on-body delivery system

OBJECTIVE

Existing healthcare systems face finite resource allocation and budgetary constraints, resulting in a substantial need for innovative solutions to enhance service delivery at reduced costs. A novel, user-friendly on-body delivery system (OBDS) was developed which enables administration of large-volume subcutaneous (SC) drugs in both clinical and home-based settings (at-home healthcare professional [HCP] administration or at-home self-administration).

METHODS

This research sought to evaluate the potential economic impact of at-home self- or HCP- administration with the OBDS through a comprehensive review of published literature and semi-structured interviews with 17 US payers representing approximately 227 million covered lives.

RESULTS

Published literature on OBDS remains limited, but available research highlights the cost-savings of SC administration due to reduced healthcare resource utilization, particularly with home-based care, and improved patient compliance. In interviews, payers identified several attributes that would help address unmet clinical and economic needs. Clinically, the hidden needle and ease-of-use compared to SC syringe pumps was deemed valuable to improve patient compliance and, as OBDS required minimal training, reduce the risk of administration errors. The flexibility to administer drugs at home (self-administration or HCP-administration) or in-clinic was identified as the most impactful attribute on coverage decision making as it has the greatest potential to reduce costs associated with HCP administration for several therapeutic areas.

CONCLUSIONS

Given the ability to help address critical unmet needs for the patient and healthcare system, a large proportion of the payers stated that the novel OBDS would warrant a price premium versus the cost of the standalone SC vial and certainly over the IV counterpart. Future research to quantify the value that OBDS efficiencies could bring to healthcare delivery are warranted.

Exploring treatment strategies for paroxysmal nocturnal hemoglobinuria: an overview of registered clinical trials

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired disease in which blood cells lack anchored proteins that regulate the complement system. The erythrocytes are then destroyed because of uncontrolled complement activity, leading to intravascular hemolysis (IVH) and a high risk of thrombosis outcome. A huge alteration in the treatment of the disease was the development of terminal complement inhibitors, with the achievement of IVH blockade, reduction or abolishment of red blood cell (RBC) transfusions, and thromboembolic events prevention. However, patients treated with these inhibitors can still present extravascular hemolysis (EVH) caused by C3 activation and residual IVH or clinically relevant levels of breakthrough hemolysis (BTH). Proximal complement inhibitors turned out to be the key to the solution of this problem by targeting components of the proximal complement pathway, avoiding intra and extravascular hemolysis. FDA approved eculizumab, ravulizumab (terminal inhibitors), pegcetacoplan, iptacopan, and danicopan (proximal inhibitors) as a treatment for PNH so far. Various clinical trials are underway to find the most effective method to treat patients with PNH. This review aimed to summarize 71 registered clinical trials in the ClinicalTrials.gov database with the various treatment drugs, possible mechanisms, and novel findings related to PNH treatment.

Clinical Pharmacology Approaches to Support Approval of New Routes of Administration for Therapeutic Proteins

Intravenous or subcutaneous routes of administration (ROAs) are common dosing routes for therapeutic proteins. Eleven therapeutic proteins with approval for one ROA have subsequently received approval for a second ROA. The clinical programs supporting the second ROA consistently leveraged data from the first ROA and included studies that characterized the pharmacokinetics (PKs) of the drug administered by the new ROA to identify an appropriate dosage regimen. The selected dosing regimen was then further evaluated in clinical trials designed with various primary end points. All programs implemented model-informed drug development approaches to ensure that the selected regimens would achieve comparable systemic exposures (PK-based bridging) or pharmacodynamic (PD) responses (PD-based bridging) as the reference ROA. To support the approval of a second ROA, these programs either demonstrated noninferiority in PK, PD, and/or clinical end points for the second ROA, or established efficacy and safety through a comparison to a placebo treatment. The accumulative examples showed that clinical trials which provided the primary evidence to support approvals of the second ROA generally demonstrated noninferiority in the systemic exposures regardless of being specified as an end point or not in the study protocols. The experience to date supports the use of PK- and PD-based bridging approaches not only in the selection of dosing regimens for a second ROA to be tested in clinical studies, but also for providing evidence of effectiveness to support approval, when appropriate.

Expansion of Anticomplement Therapy Indications from Rare Genetic Disorders to Common Kidney Diseases

Complement constitutes a major part of the innate immune system. The study of complement in human health has historically focused on infection risks associated with complement protein deficiencies; however, recent interest in the field has focused on overactivation of complement as a cause of immune injury and the development of anticomplement therapies to treat human diseases. The kidneys are particularly sensitive to complement injury, and anticomplement therapies for several kidney diseases have been investigated. Overactivation of complement can result from loss-of-function mutations in complement regulators; gain-of-function mutations in key complement proteins such as C3 and factor B; or autoantibody production, infection, or tissue stresses, such as ischemia and reperfusion, that perturb the balance of complement activation and regulation. Here, we provide a high-level review of the status of anticomplement therapies, with an emphasis on the transition from rare diseases to more common kidney diseases.

COVID-19 vaccination prevents a more severe course and treatment with complement inhibitors reduce worsening hemolysis during the Omicron pandemic in patients with PNH: a single-center study

OBJECTIVE

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disease characterized by chronic complement-mediated hemolysis. The concentrated outbreak of coronavirus disease 2019 (COVID-19) in China after 6 December 2022, provided an opportunity to observe the disease course of PNH during an active Omicron infection epidemic.

PATIENTS AND METHOD

Patients diagnosed with PNH at Peking Union Medical College Hospital (PUMCH) before 6 December 2022, were followed up until 10 April 2023. Clinical data related to coronavirus infection and hemolysis were recorded. Factors influencing the infection and severity rate of Omicron, as well as hemolysis provocation, were analyzed.

RESULTS

In total, 131 patients with PNH were included in this retrospective analysis; 87.8% were infected with Omicron. Among them, 15.7% met the criteria for severity, and 1 patient died (0.87%). No protective factors were identified against Omicron infections. However, patients with severe Omicron infection (n = 18) had a lower vaccination rate than those with non-severe infection (n = 97; p = 0.015). Among those infected (n = 115) with Omicron, there was a significant increase in lactate dehydrogenase (LDH) levels compared with those in the uninfected group (n = 16, p = 0.000). Patients with severe infections (n = 18) had even higher LDH increase rates than those without severe infections (n = 97; p = 0.002). 10 (37.0%) patients treated with complement inhibitors developed breakthrough hemolysis (BTH). Patients treated with complement inhibitors (n = 27) exhibited less severe hemolysis than treatment-naïve patients (n = 104; p = 0.003).

CONCLUSIONS

Omicron infection exacerbates hemolytic attacks in patients with PNH. Vaccination helps mitigate the severity of Omicron infection, and using complement inhibitors reduces hemolysis exacerbation.

Advancing Subcutaneous Dosing Regimens for Biotherapeutics: Clinical Strategies for Expedited Market Access

In recent years, subcutaneous administration of biotherapeutics has made significant progress. The self-administration market for rheumatoid arthritis has witnessed the introduction of additional follow-on biologics, while the first subcutaneous dosing options for monoclonal antibodies have become available for multiple sclerosis. Oncology has also seen advancements with the authorization of high-volume subcutaneous formulations, facilitated by the development of high-concentration formulations and innovative delivery systems. Regulatory and Health Technology Assessment bodies increasingly consider preference data in filing dossiers, particularly in evaluating novel drug delivery methods. The adoption of a pharmacokinetic-based clinical bridging approach has become standard for transitioning from intravenous to subcutaneous administration. Non-inferiority studies with pharmacokinetics as the only primary endpoint have started deviating from traditional randomization schemes, favoring the subcutaneous route and comparing with historical intravenous data. While nonclinical and computational models made progress in predicting safety and immunogenicity for subcutaneously dosed antibodies, clinical trial evidence remains essential due to inter-individual variations and the impact of formulation parameters on anti-drug antibody formation. Ongoing technological advancements and the expanding knowledge base on pharmacokinetic-pharmacodynamic correlation across specialty areas are expected to further accelerate clinical development of subcutaneous biologics.

Injection Site Reactions with Long-Term Pegcetacoplan Use in Patients with Paroxysmal Nocturnal Hemoglobinuria: A Brief Report

INTRODUCTION

Pegcetacoplan is a targeted complement component 3 (C3) therapy approved for adults with paroxysmal nocturnal hemoglobinuria (PNH; US) or PNH plus anemia despite C5-targeted therapy for ≥ 3 months (EU). Patients with PNH receiving pegcetacoplan in the phase 3 PEGASUS trial who experienced injection site reactions (ISRs) mostly experienced mild events. We evaluated ISR incidence and severity with longer-term treatment in the PEGASUS cohort of the Study 307 open-label extension (307 OLE).

METHODS

Patients from PEGASUS enrolled in the 307 OLE continued pegcetacoplan subcutaneous self-administration twice or three times weekly or every 3 days for an additional 48 weeks. ISRs were coded as adverse events (AEs) or treatment-emergent AEs (TEAEs) and summarized by MedDRA System Organ Class and Preferred Term.

RESULTS

As of August 27, 2021, 58/64 patients from PEGASUS completed an additional 48 weeks of treatment in the 307 OLE (median treatment duration 337.0 [range 55-344] days); 95.3% (61/64) of patients achieved compliance ≥ 80%. ISRs occurred in 9/64 (14.1%) patients in the 307 OLE, which was lower than observed at PEGASUS completion (20/77; 26.0%). Most patients with ISRs in the 307 OLE had events with a maximum severity of mild (7/9 patients; 77.8%). Injection site erythema and induration were the most common overall (4/64 patients each; 6.3%) and pegcetacoplan-related (3/64 patients each; 4.7%) ISRs. The exposure-adjusted rates of these events were each 6.5 per 100 patient-years. No ISRs were classified as severe or serious TEAEs or led to drug discontinuation.

CONCLUSION

Though ISRs were common, most were mild, and the percentage of patients reporting ISRs declined from PEGASUS through the 307 OLE. Patient compliance remained high, and no patients discontinued because of ISRs, suggesting that ISRs do not pose a barrier to long-term pegcetacoplan treatment.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT03500549 (PEGASUS) and NCT03531255 (307 OLE).

Paroxysmal Nocturnal Hemoglobinuria: Biology and Treatment

Paroxysmal nocturnal hemoglobinuria (PNH) is a nonmalignant clonal hematopoietic disorder characterized by the lack of glycosylphosphatidylinositol-anchored proteins (GPI-APs) as a consequence of somatic mutations in the phosphatidylinositol glycan anchor biosynthesis class A (PIGA) gene. Clinical manifestations of PNH are intravascular hemolysis, thrombophilia, and bone marrow failure. Treatment of PNH mainly relies on the use of complement-targeted therapy (C5 inhibitors), with the newest agents being explored against other factors involved in the complement cascade to alleviate unresolved intravascular hemolysis and extravascular hemolysis. This review summarizes the biology and current treatment strategies for PNH with the aim of reaching a general audience with an interest in hematologic disorders.