Phase 3 Randomized Study of Pirtobrutinib, Venetoclax, and Rituximab in Previously Treated Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma

The primary objective of this Phase 3 study is to evaluate **progression-free survival** in patients with previously treated **Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma** (CLL/SLL). This objective is clinically relevant as progression-free survival is a critical endpoint in assessing the efficacy of cancer treatments, indicating the length of time during and after medication that a patient lives with the disease without it worsening. The study compares a fixed duration of **pirtobrutinib** (LOXO-305) in combination with **venetoclax** and **rituximab** against the combination of venetoclax and rituximab alone. The trial aims to determine if the addition of pirtobrutinib can improve outcomes for patients with CLL/SLL.

The clinical trial involves a total of **222 participants** diagnosed with **Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma**. The study population includes both male and female subjects aged 18 and older, with a confirmed diagnosis requiring therapy as per iwCLL 2018 criteria. Participants have previously undergone at least one line of therapy, which may include a covalent Bruton's tyrosine kinase inhibitor. The trial population was selected based on specific health criteria, including adequate organ function, an Eastern Cooperative Oncology Group Performance Status of 0-2, and an estimated creatinine clearance of at least 30 milliliters per minute. Additionally, participants must have a platelet count of at least 50 x 10⁹/L, hemoglobin levels of at least 8 g/dL, and an absolute neutrophil count of at least 1.0 x 10⁹/L. The study considers vulnerable populations, and lifestyle factors such as diet and physical activity are not specified in the available data.

The clinical trial is designed as a **randomized**, open-label, controlled study to evaluate the efficacy and safety of a fixed duration of **pirtobrutinib** in combination with **venetoclax** and **rituximab** compared to **venetoclax** and **rituximab** alone in patients with previously treated **Chronic Lymphocytic Leukemia**/**Small Lymphocytic Lymphoma**. The primary objective is to assess progression-free survival as per the International Workshop on Chronic Lymphocytic Leukemia (iwCLL) Criteria 2018, evaluated by an Independent Review Committee. The trial is expected to run from November 2021 to January 2027, with participant involvement lasting up to 784 days, depending on the treatment arm.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to confirm eligibility based on criteria such as age, diagnosis, previous treatment history, and organ function. Following randomization, participants will attend regular follow-up visits to monitor treatment response and safety. These visits will include assessments of blood counts, organ function, and overall health status. The end-of-study visit will occur after the completion of the treatment period or upon early termination, which may be due to adverse events, disease progression, or withdrawal of consent.

The trial includes specific conditions for early termination, such as significant adverse reactions or lack of efficacy, as determined by the study investigators. Participants are required to meet inclusion criteria, including being 18 years or older, having a confirmed diagnosis of CLL/SLL, and having received at least one prior line of therapy. Exclusion criteria are not specified in the provided data. The study aims to provide valuable insights into the potential benefits of adding **pirtobrutinib** to the existing treatment regimen for this patient population.

The clinical trial involves the administration of **PIRTOBRUTINIB**, an experimental medication, in the form of a **tablet**. The active substance, pirtobrutinib, is of chemical origin. The maximum daily dose is 200 mg, with a total maximum dose of 156,800 mg over a treatment period of 784 days. The route of administration is **oral**, and the medication is not formulated for pediatric use. Compliance with the dosing schedule is monitored throughout the trial.

**VENETOCLAX** is used as a comparator treatment in the study. It is provided as a **film-coated tablet** with the active substance venetoclax, also of chemical origin. The maximum daily dose is 400 mg, with a total maximum dose of 274,190 mg over a treatment period of 707 days. The administration route is **oral**, and it is not a pediatric formulation. Participant adherence to the dosing regimen is closely monitored.

Another comparator treatment in the trial is **RITUXIMAB**, administered as a **solution for infusion**. The active substance, rituximab, is a protein of other origin. The maximum dose is 500 mg/m², with a total maximum dose of 2875 mg/m² over a treatment period of 6 cycles. The route of administration is **intravenous**, and it is not intended for pediatric use. The infusion schedule and participant compliance are carefully tracked during the study.

The efficacy of the clinical trial will be assessed primarily through the evaluation of **progression-free survival** (PFS) in patients with previously treated Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL). The primary endpoint is defined as PFS per the International Workshop on Chronic Lymphocytic Leukemia (iwCLL) Criteria 2018, and it will be assessed by an Independent Review Committee (IRC). This endpoint will provide a measure of the time during and after the treatment that a patient lives with the disease without it getting worse.