A Phase 1, Open-Label, Dose-Escalation Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Multiple Intravenous Doses of IGN002 Administered Weekly to Subjects with Refractory Non-Hodgkin Lymphoma

Background:Non-Hodgkin lymphoma (NHL) is the most common, adult hematologic malignancy. Despite available treatment, relapse rates are high and novel therapies are warranted. IGN002 consists of an anti-CD20 monoclonal antibody (mAb) fused to interferon-alpha (IFNα) via a short peptide linker. The mAb portion of IGN002 is a chimeric IgG1 antibody with the same amino acid sequence as rituximab. The interferon amino acid sequence is human IFNα2b (hIFNα2b). In nonclinical pharmacology studies using CD20-positive human NHL cells, IGN002 demonstrates compelling anti-tumor effects. When compared to rituximab, IGN002 demonstrated enhanced complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) effector functions against CD20-positive NHL cells. Moreover, compared to rituximab against normal human primary B-cells, IGN002 displayed higher maximal and more potent ADCC activity. Finally, in xenograft studies with immunodeficient mice using 3 different human NHL cell lines comparing IGN002 to rituximab, IGN002 demonstrated superior median and overall survival in all 3 NHL xenograft tumor lines.

Study Design and Methods:This open-label, non-randomized, first-in-human, dose finding Phase 1 study comprises a Dose-Escalation Stage and an Expansion Stage (NCT02519270). In the Dose-Escalation Stage, ascending dose cohorts will be treated in 2 periods until the maximum tolerated dose (MTD) or recommended Phase 2 dose (RP2D) is identified. In Period 1, subjects will receive 2 doses of IGN002 administered weekly. Subjects with no anti-drug antibodies to IGN002 at Week 6 in Period 1 will proceed to Period 2 and receive up to 24 additional doses of IGN002 administered weekly in three 8-week cycles, with no treatment-free interval. In the Expansion Stage, subjects will receive up to 24 doses of IGN002 at the MTD or RP2D administered weekly in three 8-week cycles, with no treatment-free interval. Cohorts 1-5 at dose level 0.1, 0.3, 1, 3, and 10 ug/kg, respectively, have been completed without any dose limiting toxicity (DLT) and enrollment for Cohorts 6-8 is impending.

Clinical Endpoints:The primary outcome measures are the evaluation of safety and tolerability of multiple doses of IGN002 administered weekly as an IV infusion to subjects with refractory NHL and the determination of MTD or RP2D of IGN002. The secondary outcome measures include characterizing the pharmacokinetic profile of ascending doses of IGN002, the incidence of anti-IGN002 antibody formation, and assessment of anti-tumor activity (e.g., response rate, duration) of IGN002 using the Lugano Classification criteria for NHL.

Eligibility Criteria:This study is enrolling patients > 18 years with an ECOG <2 who have a documented history of immunohistochemistry-confirmed CD20-positive B-cell NHL, including diffuse large B-cell, mantle cell, marginal zone, lymphoplasmacytic, follicular, transformed follicular, or primary mediastinal B-cell lymphoma that is refractory to at least 1 documented regimen containing rituximab or a similar anti-CD20 therapy. Patients must also have measurable disease and adequate organ function. The exclusionary criteria encompass treatment with an approved or investigational chemotherapy or anti-CD20 drug within 28 days of Day 1, treatment with an approved or investigational biologic drug that does not target CD20 within 90 days of Day 1, or radiation therapy within 4 weeks of Day 1.

Statistical Methods:The sample size was not predicated on formal statistical considerations. Descriptive statistics will be used to summarize continuous variables. Dichotomous endpoints will be summarized using frequencies, proportions, and exact binomial 95% CI. For subjects treated at the MTD or RP2D in Period 2 of the Dose-Escalation Stage and the Expansion Stage, time-to-event variables will be summarized using the Kaplan-Meier method.

Target Accrual:In the Dose-Escalation Stage and Expansion Stage, approximately 9-18 (~3-6 subjects per cohort) and 14 subjects, respectively, will be accrued. Enrollment for Cohort 6 is expected to commence in September 2020.