A Phase 1b Open-Label Study of Loncastuximab Tesirine in Combination with Other Anticancer Agents in Patients with Relapsed or Refractory (R/R) B-Cell Non-Hodgkin Lymphoma (LOTIS-7)

Background: Patients (pts) with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL) may not respond well to single-agent therapy. Combining agents with different mechanisms of action may enhance the efficacy of single agents. Loncastuximab tesirine (loncastuximab tesirine-lpyl; Lonca) is an FDA-approved CD19-directed antibody-drug conjugate (ADC) indicated for R/R large B-cell lymphoma and showed significant antitumor activity and manageable toxicity in a phase 2 trial in pts with R/R diffuse large B-cell lymphoma (Lancet Oncol 2021;22(6):790-800). In preclinical xenograft models, Lonca in combination with gemcitabine, polatuzumab vedotin (Pola), or phosphatidylinositol 3-kinase inhibitors showed improved antitumor activity. The safety and activity of Lonca in combination with other established anticancer agents in pts with R/R B-NHL will be evaluated in LOTIS-7.

Methods: LOTIS-7 is a phase 1b, open-label, multicenter, multiarm study (NCT04970901) with 2 parts: dose escalation (part 1) and dose expansion (part 2). Approximately 200 pts with B-NHL will be enrolled (part 1, 70 pts; part 2, 130 pts). Part 2 may include DLBCL, high-grade B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, marginal zone lymphoma, and Burkitt lymphoma cohorts. The design of part 2, such as the sample size, population, etc., may be informed by data collected in part 1. For safety, tolerability, and identifying the maximum tolerated dose and/or recommended dose for part 2, primary endpoints are frequency and severity of adverse events (AE), serious adverse events, dose-limiting toxicities during cycle 1, and frequency of dose modifications due to AE. For efficacy, pharmacokinetics, and immunogenicity, secondary endpoints are overall response rate, duration of response, complete response rate, progression-free survival, relapse-free survival, overall survival, Lonca concentrations, and antidrug antibodies to Lonca titers.

Multiple arms are planned; currently, enrollment is open to 1 arm, wherein patients will be treated with Lonca + Pola as an outpatient infusion every 3 weeks (Q3W). In part 1, patients will receive Lonca at escalating doses (from 90 µg/kg to 150 µg/kg) and Pola at a dose of 1.8 mg/kg on day 1 of each 3-week cycle. In part 2, patients will receive Lonca in combination with Pola at the maximum tolerated dose and/or recommended dose for expansion if favorable results in part 1 are achieved. The study has a screening period (≤28 days from the day of the first dose), a treatment (Tx) period (cycles Q3W, ≤1 year), and a follow-up period (~Q12W visits, ≤2 years after Tx discontinuation). Treatment may continue for up to 1 year or until disease progression, unacceptable toxicity, or other discontinuation criteria-whichever occurs first. Key inclusion criteria are patients age ≥18 years with a pathologic diagnosis of R/R B-NHL (2016 WHO classification) and the following: those who failed/are intolerant to any approved Tx, received ≥2 systemic Tx regimens, need systemic Tx, have an ECOG performance status of 0-2, and have measurable disease (2014 Lugano Classification). Patients who previously received any study drugs; received a stem-cell transplant within 60 days prior to the start of study drugs; have lymphoma with active CNS involvement, serious skin-related disease, ascites, edema, or effusion; and have significant medical comorbidities are excluded.

Results: The study opened in December 2021, and the first patient was dosed in the Lonca + Pola arm in June 2022.

Funding: ADC Therapeutics SA; medical writing: CiTRUS Health Group.

Hess:Bristol-Myers Squibb: Consultancy; AstraZeneca: Consultancy, Speakers Bureau; ADC Therapeutics: Consultancy. Collins:ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SecuraBio: Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel grants / expenses, Speakers Bureau; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel grants / expenses, Speakers Bureau. Solh:ADC Therapeutics: Research Funding; Partner Therapeutics: Research Funding. Gandhi:TG Therapeutics: Honoraria; Janssen: Honoraria; Karyopharm: Honoraria; GlaxoSmithKline: Honoraria. Wang:ADC Therapeutics: Current Employment, Current equity holder in private company, Current holder of stock options in a privately-held company. Qin:ADC Therapeutics: Current Employment, Current equity holder in publicly-traded company, Other: Current holder of stock options publicly-traded company. Yu:ADC Therapeutics: Current Employment, Current equity holder in private company, Current holder of stock options in a privately-held company. Zinzani:TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; University of Bologna: Current Employment; MSD: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Secura Bio: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Beigene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

The safety and activity of loncastuximab tesirine (Lonca) in combination with other established anticancer agents in pts with R/R B-NHL will be evaluated in LOTIS-7. Lonca is FDA-approved for the treatment of adult patients with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy, DLBCL not otherwise specified, DLBCL arising from low grade lymphoma, and high-grade B-cell lymphoma.