Patrys Ltd (ASX:PAB) believes it stands to benefit from growing momentum in the antibody drug conjugates (ADCs) space.
The ASX-listed healthcare stock is focused on developing new antibody treatments to combat cancer and its flagship deoxymab antibody, PAT-DX3, can be used as a targeting agent for ADCs to deliver anti-cancer drugs to tumours.
With a market cap of roughly A$53 million, Patrys represents a small-cap ADC opportunity in a big pond: the latest round of deals in this space involve large-cap biotech movers and shakers like MacroGenics, Mersana and Jannsen.
In a newsletter on Tuesday, CEO and managing director Dr James Campbell outlined the growing upside in the ADC space — and how Patrys is poised to capitalise on momentum.
Patrys’ mission
Patrys is focused on developing its cornerstone deoxymab platform, which is based on the eponymous antibody and falls under an exclusive worldwide licence with Yale University.
While most antibodies bind to cell surface markers, deoxymab penetrates into the cell nuclei and binds directly to DNA, where it inhibits DNA repair processes.
Cancer cells often have high levels of mutations and underlying deficiencies in the DNA repair mechanisms, so by inhibiting the DNA repair processes, deoxymab can kill cancer cells while appearing to have little impact on normal cells.
As a single agent, deoxymab has been shown to significantly enhance the efficacy of both chemo- and radiotherapies.
Further, deoxymabs can be conjugated to nanoparticles to target delivery of chemotherapeutics and imaging agents to tumours.
Targeting agent potential
Late last year, Patrys announced new data from a preclinical study that demonstrated potential to use its deoxymab antibodies as targeting agents in ADCs.
At the time, Dr Campbell said: “While most ADCs are based on antibodies directed against cell surface antigens that are specific for a particular tumour, our deoxymabs are attracted to the DNA that is released from most cancers as a result of the high rates of cell death and cell turnover in tumours.
“This preclinical study has shown that the affinity our deoxymabs have for DNA is sufficient for them to target the delivery of cancer drugs to tumours where they can inhibit tumour growth and improve survival.
“This exciting finding may open up new opportunities for deoxymabs as a basis for developing new therapeutic ADC products.
“Additional studies will need to be performed to better understand the potential impacts of on-target and off-target toxicity using this approach; however, the results from this study have clearly demonstrated the proof-of-concept.
“We look forward to advancing this program as an adjunct to our planned first in-human clinical study of PAT-DX1, which remains on track for late 2022.”
ADCs in the news
As Patrys gears up to move to human trials, it’s buoyed by the growing interest in ADCs across the healthcare landscape.
Earlier this month, US biotech MacroGenics said it would pony up US$586 million to help develop and commercialise a clinical ADC platform with Netherlands-based Synaffix.
And just last week, Mersana Therapeutics (NASDAQ:MRSN) and Johnson & Johnson (NYSE:JNJ)’s Janssen Biotech inked a research and licensing deal to investigate ADCs — a pact that could be worth as much as US$1 billion.
Patrys’ work in the ADC space means it’s a small-cap investment opportunity in a field that’s increasingly grabbing the big players’ attention.
Dr Cambell signed off today’s newsletter optimistic about the company’s future prospects.
“While our focus is on advancing PAT-DX1 and PAT-DX3 as single agents for cancer, the potential upside from our work in the ADC space is truly exciting,” he concluded.