Patrys Ltd (ASX:PAB) continues to build momentum for its drug pipeline, with strong clinical evidence supporting its deoxymab platform and a sturdy balance sheet to fund its efforts into the new calendar year.
Patrys is a therapeutic antibody development company focused on the development of derivative treatments from its deoxymab platform, first identified as an autoantibody in a mouse model of the human disease systemic lupus erythematosus (SLE).
While most antibodies bind to cell surface markers, deoxymab penetrates the cell nuclei and binds directly to DNA where it inhibits DNA repair processes. The company is developing its PAT-DX1 treatment, as well as full-sized IgG (Immunoglobulins) deoxymab antibody, PAT-DX3.
“Broad and promising utility”
Patrys CEO and managing director Dr James Campbell said in the company’s September quarterly report: “This quarter has delivered a period of significant momentum for Patrys.
"We have continued to build the portfolio of data for deoxymabs which has further expanded the broad and promising utility for our antibody assets in addition to meeting important research milestones as we head towards the clinic.
“Most notably, the successful preclinical study that demonstrates the potential for using our deoxymab antibodies as targeting agents in antibody drug conjugates (ADCs), has opened up a range of new development and partnering possibilities for our platform.
“Our financial position also remains strong and, despite some minor production delays due to COVID-19, we remain on track to complete the first full-scale manufacturing run of clinical-grade PAT-DX1 before year-end and to commence the preclinical toxicology studies required for our phase 1 trial in early 2022 as planned.”
Research and development
Both PAT-DX1 and PAT-DX3 have been proven capable of crossing the blood-brain barrier (BBB) in animal models of primary brain cancer (glioblastoma multiforme or GBM). The BBB prevents many drugs and virtually all therapeutic antibodies from entering the brain.
Having a full-sized IgG antibody such as PAT-DX3 which is able to cross the BBB opens several potential therapeutic opportunities for Patrys, including looking at the possibility of using deoxymabs to deliver therapeutic payload to primary and secondary brain cancers.
In July, Patrys announced new data showing that PAT-DX1 is able to reduce tumour growth by 26% and improve survival by 47% in an animal model of pancreatic cancer.
PAT-DX1 has now been shown to significantly reduce tumour growth in multiple animal models of difficult-to-treat solid tumours including glioblastoma (brain cancer), triple negative breast cancer (TNBC), and now pancreatic cancer.
This adds to the compelling data set Patrys has been building in relation to its lead PAT-DX1 asset ahead of its planned clinical trial in 2022.
In September 2021, Patrys announced proof-of-concept data that supports the potential use of PAT-DX3 as a cancer-targeting agent for antibody drug conjugates (ADCs).
Antibody drug conjugates are designed to leverage the targeting attributes of antibodies to deliver therapeutic payloads to sites of disease. Patrys conjugated the anti-cancer drug monomethyl auristatin E (MMAE) to its full-sized IgG deoxymab, PATDX3.
In an animal model of human breast cancer, administration of PAT-DX3-MMAE ADC resulted in statistically significant 95% inhibition of tumour growth by day 31.
Patrys reported positive survival data for this study on October 18, 2021, noting that only 20% of PAT-DX3-MMAE treated animals had died at the end of the experiment (day 60), while 50% of untreated animals had died by day 35, and all untreated animals had died by day 49.
Read: Patrys' deoxymab conjugate increases breast cancer survival rate in animal model
The results from this study have clearly demonstrated the proof-of-concept and Patrys looks forward to advancing this program.
Corporate update
During the quarter ended September 30, 2021, Patrys had net cash outflows of A$1.175 million, with A$605,000 invested in R&D activities. On September 30, 2021, Patrys held A$5.862 million in cash and A$4.0 million in term deposits, a total of A$9.862 million.
Based on the net cash used in operating activities in the September quarter, the company has 8.39 quarters of funding available. Payments to related parties and their associates during the quarter were A$255,000.