Parthenon Therapeutics, a precision oncology company inventing a novel class of anti-cancer therapies that reprogram the tumour microenvironment (TME), and ImaginAb, a global biotechnology company developing 89Zr crefmirlimab berdoxam (CD8 ImmunoPET) imaging agent and radiopharmaceutical therapies (RPT) products, announced that they have entered into a multi-year, non-exclusive license and supply agreement.
Key highlights:
- Under the terms of the agreement, ImaginAb will supply clinical doses of its investigational CD8 ImmunoPET technology to Parthenon Therapeutics for use in its Phase 1 trial clinical development of PRTH-101.
- PRTH-101 targets discoidin domain receptor 1 (DDR1) to punch holes in the mechanical barrier that characterises immune-excluded tumours, thereby making them vulnerable to attack by the immune system.
- ImaginAb’s CD8 ImmunoPET technology will be a less invasive approach compared to the current biopsy-based standard of care and is consistent with the objective of generating a rich dataset of biomarker endpoints.
Under the agreement terms, Parthenon will use ImaginAb’s CD8 ImmunoPET imaging technology in its Phase 1 trial evaluating its lead compound, PRTH-101, which is expected to begin in 2023.
“Parthenon is developing an entirely new class of anti-cancer therapies that can modulate the TME in immune-excluded tumors through our proprietary approach that utilises biomarkers to match our therapeutic approaches to individual patients based on the specific characteristics of their cancer,” said Laurent Audoly, Ph.D., chief executive officer and co-founder of Parthenon Therapeutics.
“ImaginAb’s CD8 ImmunoPET technology will provide us with critical insight into the infiltration of CD8 T cells in the TME, not only for a small part of a single lesion but also for an entire tumour as well as all tumours throughout a patient’s body. This approach is less invasive compared to the current biopsy-based standard of care and is consistent with the objective of generating a rich dataset of biomarker endpoints leveraging orthogonal approaches in the earliest phases of our clinical trial.
"PRTH-101 targets discoidin domain receptor 1 (DDR1) to punch holes in the mechanical barrier that characterises immune-excluded tumours, thereby making them vulnerable to attack by the immune system. The CD8 ImmunoPET data will be used in our Phase 1 trial to quantify the degree of immune infiltration into tumours before and after dosing and be used to identify tumours that are ‘hot’, ‘cold’ or ‘immune excluded’. This knowledge will help us design a clinical strategy to focus on those patients who will benefit the most from treatment with PRTH-101.”
Hot tumours are characterised by the presence of CD8+ T cells that are able to infiltrate the tumour parenchyma. These tumours often respond to immune checkpoint inhibitors, unlike cold tumours which have few to no CD8+ T cells. In contrast to both hot and cold tumours, immune excluded tumours have CD8+ T cells in the tumour bed, but these cells are relegated to the tumour stroma by collagen and/or other barriers, thereby preventing them from interacting with tumour cells to perpetuate an anti-tumour response. PRTH-101 targets the collagen barrier of immune excluded tumours, thereby enabling CD8+ T cells to interact with and kill tumour cells. Immune-excluded tumours can represent up to 75 percent of a TME phenotype across different tumour types highlighting the potential for identifying therapeutics that can help many patients.
“We are excited to provide our cutting edge CD8 imaging technology to Parthenon which allows changes in CD8+ T-cell distribution to be visualised before and after therapy,” said Ian Wilson, chief executive officer of ImaginAb.
“Parthenon joins an increasing number of pharma and biotech companies incorporating our CD8 ImmunoPET agent into their clinical trials to precisely understand the therapeutic activity and treatment outcomes of investigational novel oncology assets in cancer patients at a very early stage. CD8+ T-cells play a pivotal role in immunotherapy and CD8 ImmunoPET has demonstrated the potential to track CD8+ T-cells using whole body PET scans in clinical trial subjects.”
Under the terms of the agreement, ImaginAb will supply clinical doses of its investigational CD8 ImmunoPET technology to Parthenon Therapeutics for use in the clinical development of PRTH-101 at clinical trial sites across the United States. Initially, Parthenon Therapeutics will investigate CD8 status in a Phase I dose escalation clinical trial of PRTH-101, both in monotherapy and in combination with anti-PD(L)1 therapy. The trial is expected to initiate in 2023, with the ability to add dose expansion cohorts at a later date to explore additional rational combination opportunities and tumor types.
ImaginAb will receive payments for providing dose manufacturing and ongoing technical, clinical and regulatory support to enable the successful implementation of its CD8 ImmunoPET technology into Parthenon Therapeutics’ clinical trials.
ImaginAb is actively investing in the clinical and global supply chain development of CD8 ImmunoPET agent to provide simple turnkey access to its novel technology for use in clinical research and development. By collaborating with leading biotech companies, ImaginAb is making progress towards the company’s goal of being a key partner in the development of new immunotherapies across multiple cancer types and geographies.