A Phase IB, Randomized, Placebo-Controlled Study Evaluating the Safety, Pharmacokinetics, Pharmacodynamics, and Efficacy of Crovalimab for the Management of Acute Uncomplicated Vaso‑Occlusive Episodes (VOE) in Patients With Sickle Cell Disease (SCD)

The primary objective of this study is to evaluate the **safety** of crovalimab compared with placebo in the management of acute uncomplicated vaso-occlusive episodes in patients with **Sickle Cell Disease**. This is clinically relevant as it aims to determine the risk profile of crovalimab, which is crucial for ensuring patient safety and guiding therapeutic decisions.

Secondary objectives include:

• To evaluate the **pharmacokinetics** (PK) of crovalimab, which will provide insights into the drug's absorption, distribution, metabolism, and excretion.
• To evaluate the **pharmacodynamics** (PD) of crovalimab, assessing the drug's biological effects and mechanism of action.
• To evaluate the **efficacy** of crovalimab compared with placebo, determining its therapeutic benefit in reducing vaso-occlusive episodes.
• To evaluate the **immune response** to crovalimab, which is important for understanding potential immunogenicity and long-term safety.

The clinical trial involves a total of **37 participants** diagnosed with **Sickle Cell Disease**. The study population includes both male and female subjects, with an age range that encompasses children and adolescents. Participants were selected based on specific criteria, including a confirmed diagnosis of HbSS or HbSβ0 genotypes, a body weight of at least 40 kg, and adequate hepatic and renal function. Additionally, participants must have been vaccinated against Neisseria Meningitidis, H. influenzae type B, and S. pneumoniae. The trial also requires that participants have a diagnosis of an acute uncomplicated vaso-occlusive episode necessitating hospital admission and treatment with parenteral opioid analgesics. Those receiving sickle cell therapies must be on a stable dose for at least 28 days. The trial population includes individuals from a vulnerable population, ensuring a comprehensive evaluation of the safety of crovalimab compared with placebo.

The clinical trial is a **Phase 3**, randomized, placebo-controlled study designed to evaluate the safety, pharmacokinetics, pharmacodynamics, and efficacy of **Crovalimab** in managing acute uncomplicated vaso-occlusive episodes in patients with **Sickle Cell Disease**. The trial employs a double-blind methodology to ensure unbiased results, with participants randomly assigned to receive either Crovalimab or a placebo. The study is expected to run until October 31, 2025, with recruitment having commenced on December 12, 2022.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to confirm eligibility based on criteria such as body weight, confirmed diagnosis of specific Sickle Cell Disease genotypes, and adequate hepatic and renal function. Following successful screening, participants will be randomized and receive either Crovalimab or placebo via intravenous or subcutaneous administration. The trial includes multiple follow-up visits to monitor safety and efficacy, with primary endpoints focusing on the incidence and severity of adverse events, changes in vital signs, and clinical laboratory test results. Secondary endpoints will assess serum concentrations of Crovalimab, pharmacodynamic biomarkers, and the prevalence of anti-drug antibodies.

The expected duration of participant involvement is contingent upon the trial's timeline, with conditions for early termination including the occurrence of severe adverse events or withdrawal of consent. The end-of-study visit will conclude the participant's involvement, during which final assessments will be conducted to evaluate the overall impact of the treatment. The trial's design ensures rigorous monitoring and data collection to achieve its primary objective of evaluating the safety of Crovalimab compared to placebo.

The clinical trial involves the administration of **Crovalimab**, an experimental medication, which is a **solution for injection/infusion**. Crovalimab is a protein-based therapeutic agent developed by F. Hoffmann-La Roche Ltd. The pharmaceutical form of Crovalimab is specifically designed for either **intravenous (IV)** or **subcutaneous (SC)** administration. The dosing schedule and frequency of administration are determined based on the study protocol, ensuring optimal evaluation of its safety, pharmacokinetics, pharmacodynamics, and efficacy in managing acute uncomplicated vaso-occlusive episodes in patients with **sickle cell disease**. Participant compliance with the dosing regimen is monitored throughout the study to ensure adherence to the protocol.

In addition to the experimental treatment, the study includes the use of a **placebo** control, referred to as Crovalimab Placebo. The placebo is utilized to provide a baseline for comparison against the active treatment, allowing for a rigorous assessment of Crovalimab's therapeutic effects. The placebo does not contain any active substance and is administered in a manner consistent with the experimental drug to maintain the study's blinding. The use of a placebo is critical in distinguishing the true efficacy and safety profile of Crovalimab from any potential placebo effects.

The efficacy of **Crovalimab** in the management of acute uncomplicated vaso-occlusive episodes (VOE) in patients with sickle cell disease (SCD) will be assessed through several secondary endpoints. These include the measurement of serum concentrations of Crovalimab over time and the analysis of relationships between drug exposure and pharmacodynamics, efficacy, or safety endpoints in patients randomized to receive Crovalimab. Additionally, changes over time in pharmacodynamic biomarkers such as CH50, free C5, and sC5b-9 will be evaluated. The time to improvement of the primary acute uncomplicated VOE from baseline will also be a key parameter. Furthermore, the prevalence of anti-drug antibodies (ADAs) at baseline and the incidence of ADAs during the study will be monitored.