Abstract CT128: IMU-201-101 - an open-label, multi-center, dose escalation/expansion, phase 1 study of IMU-201 (PD1-Vaxx), a B-cell immunotherapy, in adults with non-small cell lung cancer
Authors: Kaumaya Pravin , Bekaii-Saab Tanios , Phan Tri , Marino Mark T. , Ede Nick , Good Anthony 
Published: September 2020

Background: The inhibitory immune pathway, consisting of the receptor programmed cell death 1 (PD-1) and its ligands, PD-L1 and PD-L2, plays a vital role in the maintenance of peripheral tolerance. Therapies with monoclonal antibodies targeting PD-1 and its ligands are associated with remarkable response rates in various cancers. Imugene is proposing to develop an anti-PD-1 immunotherapy using a vaccine approach to treat patients with tumors that over-express PD-L1. The hypothesis is that a polyclonal-induced B-cell antibody response will be more effective or as effective with improved safety over current monoclonal antibody therapy. IMU-201, is a B-cell epitope (amino acids 92-110 from PD-1) linked to a promiscuous T cell epitope (amino acid residues 288-302 from measles virus fusion protein) via a 4-amino acid linker (G-P-S-L), combined in an aqueous phase vaccine to be emulsified in Montanide ISA 720 VG, to form the drug product.

Study Design: IMU-201-101 is a 2-part open-label dose escalation/dose expansion study of IMU-201. Part 1 will dose escalate IMU-201 as monotherapy and in combination with Standard of Care (SOC) treatment to evaluate safety, tolerability and immunogenicity and assess the optimal biologic dose (OBD) of IMU-201. Part 2 will expand the number treated with IMU-201 at OBD in combination with SOC treatment. OBD is defined as the dose resulting in the best safety/tolerability and immunogenicity and will be determined after all dose cohorts have completed Day 29 of Part 1.

A total of approximately 30 adult patients aged 18 years with NSCLC expressing PD-L1 will be enrolled in the study at sites in North America and Australia.

In Part 1, three cohorts (25, 125 and 250 µg of IMU-201) of 3-6 participants per cohort are anticipated to establish the Optimum Biological Dose (OBD) of IMU-201 as monotherapy (mOBD). After establishing mOBD, combination dose escalation will combine IMU-201 with SOC treatment which may include ICI, chemotherapy or their combination, to establish combination OBD (cOBD). The starting dose for combination dose escalation will be one dose level below mOBD. The same dosing schedule of IMU-201, DLT criteria, and dose escalation rules will be used to establish mOBD and cOBD. In Part 2, the number of patients treated in combination with IMU-201 at cOBD will be expanded to 12 patients.

Patients will receive IMU-201 at Baseline/Day 1, Day 15 and Day 29. Dosing with IMU-201 will continue at Day 64 (± 7 days) and every subsequent 63 days (± 7 days) until progressive disease or complete response. Therapy may continue beyond progression if the treating physician feels that the patient is deriving benefit.

Primary Objectives:

To evaluate the safety/tolerability and immunogenicity of IMU-201 as monotherapy and in combination with SOC treatment.

To identify OBD of IMU-201 as monotherapy and in combination with SOC treatment.

To evaluate changes in immunological, biochemical and additional radiological markers of tumor progression in patients treated with IMU-201 as monotherapy and in combination with SOC treatment.

To evaluate changes in humoral and cellular immunogenicity data including PD-1 specific antibodies (IgG, IgM), vaccine-specific cytokine levels and regulatory and effector T and B cells.

Citation Format: Pravin Kaumaya, Tanios Bekaii-Saab, Tri Phan, Mark T. Marino, Nick Ede, Anthony Good. IMU-201-101 - an open-label, multi-center, dose escalation/expansion, phase 1 study of IMU-201 (PD1-Vaxx), a B-cell immunotherapy, in adults with non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT128.