- A preclinical proof-of-concept (PoC) was obtained for candidate PBA-0405 based on its ability to inhibit tumor growth in a human tumor model containing a molecular target (ROR-1). The positive results in this model justify further development of PBA-0405 for the treatment of solid tumors and directly support the rationale for the first human trial in head and neck cancer patients in late 2023 under Phase 0.
- PBA-0405 effectively reduces the number of leukemic cells containing the molecular target ROR-1 in the spleen and bone marrow, as demonstrated in a pilot study conducted
on a 4-week-old mouse model of leukemia, justifying the planned further development of PBA-0405 for the treatment of B-cell leukemia in a Phase 1 clinical trial.
- A pilot tolerability study of PBA-0405 in humanized mice with tumors presenting the molecular target ROR-1 showed no apparent toxicity at doses up to 70 mg/kg, which is above the intended dosage in oncology patients.
- A safety study qualifying PBA-0405 for a Phase 0 study in humans is currently underway in humanized mice. According to the study plan, full study results are expected in September 2023.
The PB004 project is progressing on schedule for submission of an application for FDA approval (eIND) and initiation of a Phase 0 study in the fourth quarter of 2023.
Dr. Pieter Spee, Board Member and Chief Scientific Officer of Pure Biologics said:
The in vivo results in the PB004 project make us very optimistic. The achieved efficacy parameters and safety profile in the mouse model are very promising in the context of the planned Phase 0 and Phase I clinical trials. Even before the end of the year, we plan to obtain FDA approval and start the first Phase 0 study in humans.
Dr. Filip Jeleń, co-founder and CEO of Pure Biologics said:
As announced, we are meeting the development schedule for our flagship drug projects. Parallel to the in vivo studies in the PB004 project, we are pursuing the PB003G study. Results in the second project are expected in the coming weeks.
The obtained results of in vivo studies are very important, among other things, in the context of cooperation with potential partners – they can be an important element in the decision-making processes of pharmaceutical companies. As announced, we would like to bring about the signing of a partnership agreement for at least one of the projects.
The goal is to seal a partnering transaction for either the PB003G or PB004 project. Since 2022 Pure Biologics has been intensifying partnership talks and has identified several potential pharmaceutical partners. According to the Company, the progress of the talks indicates that the first transaction could potentially be possible once the expected results of animal studies are available.
Project PB004 is a potential biologic drug. It involves the development of a new therapeutic molecule in the format of an affucosylated IgG1 class antibody, which is expected to stimulate the immune response of NK cells against tumor cells bearing the tumor antigen ROR-1, leading to their direct killing by an antibody-dependent cellular cytotoxicity (ADCC) mechanism. The PB004 molecule is being developed for the treatment of solid tumors, including triple-negative breast cancer, as well as for the treatment of selected hematological malignancies, including chronic lymphocytic leukemia, among others.
Project PB003G is developing a dual-action therapeutic antibody that simultaneously eliminates immunosuppressive regulatory T (Treg) cells in the tumor microenvironment and stimulates cytotoxic NK and T cells to directly target tumor cells. According to the Company, the results of the PB003G project show clear advantages over drug candidates with promising results in early clinical development. PB003G is an attractive drug concept with a very strong competitive advantage for commercialization in the cancer therapy market, with potential in the treatment of solid tumors.
The Company plans to pursue both projects in a novel approach involving a Phase 0 clinical trial, which may allow the first information on the compounds’ efficacy in humans to be obtained up to two years sooner than the classic approach, based on Phase I and II clinical trials. At the same time, the data will be obtained at a significantly lower financial burden than that of the aforementioned classical approach.
The ongoing Development Plans are expected to allow the Company to complete the full suite of preclinical studies up to Phase 1 and IND filing, and to be ready to initiate Phase I clinical trials in patients with solid tumors (PB003G) and leukemia (PB004) in Q4 2024.