Clinical-stage oncology company Prescient Therapeutics’ (ASX: PTX) strong cash position will enable it to advance its multiple cancer programs, with work to follow on from what managing director Steven Yatomi-Clarke describes as “tremendous” FY 2021.
The company develops personalised medicinal approaches to cancer, including targeted and cellular therapies.
Its targeted therapy candidates PTX-100 and PTX-200 are designed to inhibit cancer growth and tumour survival, while OmniCAR is a universal immune receptor platform being developed for next-generation CAR-T therapies for acute myeloid leukemia, HER2-positive solid tumours including breast, ovarian and gastric cancers, and glioblastoma multiforme (brain cancer).
Prescient ended the June quarter with $16.1 million cash in the bank after spending $280,000 on research and development activities in Australia and the United States, particularly related to the development of OmniCAR and cell therapy enhancements, and the ongoing clinical studies of PTX-100 and PTX-200.
Recent accomplishments include successful results from a phase 1b trial of PTX-100, announced after 30 June, which has led to an expanded study of the drug candidate to treat T cell lymphoma, and trial and manufacturing milestones achieved in the development of the OmniCAR platform.
PTX-100 trial progress
At the end of July, Prescient reported results from the PTX-100 phase 1b basket trial in solid and hematological cancers that demonstrated the drug was very well tolerated at all dose levels.
Early clinical activity was also observed in two patients with aggressive disease, in which prior therapies had failed to stop its progression. One of the patients experienced a partial response (a reduction in cancer burden) from the therapy with no disease progression for 17 months so far, while the other patient experienced a reduction in cancerous lesions and symptomatic .
“In both cases, such patients with refractory T cell lymphoma on standard-of-care therapies would typically be expected to have disease progression within four months, highlighting the encouraging nature of these responses,” Prescient reported.
Owing to these encouraging phase 1b results, the company is now progressing development of PTX-100 as a monotherapy in an expansion cohort study in relapsed and refractory T cell lymphoma.
If the expansion cohort is successful, Prescient could advance directly to a separate registration study which may only require small trials compared to typical phase three trials.
Prescient’s other targeted therapy, PTX-200 is currently undergoing a phase 1b clinical trial in patients with acute myeloid leukemia. Updates from this study is expected in coming months.
To expedite its OmniCAR milestones, Prescient expanded its research partnership with the world-renowned Peter MacCallum Cancer Centre during the June quarter.
The partnership will fast-track development of Prescient’s next generation CAR-T therapy using the OmniCAR platform.
also recently announced “excellent” results from independent in silico immunogenicity testing of OmniCAR’s key binding components, SpyTag and SpyCatcher.
According to the company, this is a key milestone that substantially de-risks the entire platform and is important for progressing Prescient’s in-house programs and external collaborations.
Immunogenicity testing evaluates the immune response against a new therapy. In the case of CAR-T cell therapies, high levels of immunogenicity can adversely impact CAR-T cell expansion and persistence, which can impact the overall safety and clinical response of the treatment.
OmniCAR’s binding system components SpyTag and SpyCatcher were independently tested by a US research provider with results demonstrating that both components have very low immunogenicity – on par with circulating human antibodies.
Prescient chief executive officer and managing director Steven Yatomi-Clarke said the results “could not have been better”.
“It gives us confidence that if these therapies are ultimately delivered to patients, their immune systems will not impair the therapy itself.”
“This is essential not only for Prescient’s three in-house OmniCAR programs, but also for potential external collaborators, who consider immunogenicity very stringently,” he added.
The development followed the successful completion of manufacturing and delivery of critical components of the OmniCAR platform including cell binders for several cancer targets and lentiviral vectors used to produce CAR-T cells.