An Open Label Phase Ia/b Dose Escalation Followed by Dose Expansion Safety and Tolerability Trial of CAP-100, a Humanized C-C-chemokine Receptor 7 Antibody, Administered as Monotherapy in Subjects With r/r Chronic Lymphocytic Leukemia

Introduction of immuno-chemotherapy in the treatment options of CLL and SLL changed the treatment paradigm of these diseases. Presently, first-line therapies for CLL/SLL include targeted therapies (e.g. ibrutinib, acalabrutinib) or combined immuno-chemotherapy regimens (e.g., fludarabine, cyclophosphamide, and rituximab for patients aged <65 years without del17p/TP53 mutations or bendamustine and rituximab for patients ≥65 years who have additional comorbidities).

Despite the gradual introduction of targeted therapies, new treatment strategies efficacious for patients ineligible for/unresponsive to these therapies are still required. These new strategies should ideally overcome disease relapse and circumvent compound-specific safety challenges. Emerging treatment options include new compounds aimed for both untreated and relapsed/refractory CLL, and combination therapies of existing compounds that extend single-agent efficacy in specific high-risk patient populations.

CAP-100 is expected to prevent the migration of leukemia cells to and their survival in lymphoid niches as well as to eliminate CCR7-positive leukemia cells via ADCC, resulting in measurable clinical responses.

The present trial is the first-in-human trial of CAP-100 and is divided into two phases. The aim of the Phase Ia (dose escalation) is to define the Recommended Phase 2 Dose (RP2D) versus the Maximum Tolerated Dose (MTD) of CAP-100 in subjects with CLL.

Phase Ib of the trial (expansion phase) will evaluate the safety and preliminary clinical benefit of CAP-100 monotherapy at RP2D (response rate, lymph node size reduction, assessment of minimal residual disease [MRD]) to support the design of future trials investigating CAP-100 either as monotherapy or in a combination setting with approved treatments for CLL.