Clinical stage oncology company PharmAust (ASX: PAA) has attributed a successful June quarter performance to lead drug monepantel and monepantel sulfone which has shown “remarkable” early results against COVID-19 infections.
During the quarter, the company entered into a materials transfer agreement with Melbourne’s Walter and Eliza Hall Institute of Medical Research to test the effects of the drug on cells infected with the current coronavirus strain (or SARS-CoV-2).
The results proved “very positive” according to PharmAust, with repeat cell culture work “confirming initial promising data” which showed monepantel and monepantel sulfone treatment could reduce COVID-19 cell-to-cell infectivity.
The drug suppressed virus infectivity by approximately 95% in cell culture, and the quantities of monepantel required to achieve this suppression were considered to be in the clinically acceptable range.
Better than expected
Institute researcher and joint head of the Infectious Diseases and Immune Defence division Professor Marc Pellegrini said the results were better than expected.
“These repeat results validate the outcomes of the initial test and form strong grounds for progressing this drug to the next step,” he said.
“Demonstrating twice that infectivity of SARS-CoV-2 virus particles can be suppressed by up to approximately 95% in cell cultures is a remarkable outcome.”
PharmAust and the Institute are conducting a comparative analysis on human pulmonary epithelial cells with monepantel and other mTOR inhibitors, such as rapamycin and anti-viral drugs currently authorised by the US Food and Drug Administration for emergency use to treat COVID-19, including remdesivir.
Once these assays are received, PharmAust will commence discussions on a phase I trial in a small number of human patients with COVID-19.
In 2015, oral monepantel was evaluated in PharmAust’s first-in-man clinical trial on patients with treatment-refractory solid tumours and was demonstrated to have a good safety profile and was well-tolerated compared to established anti-cancer drugs.
PharmAust said this safety data will be used to facilitate the next steps for phase 1 preparation.
During the June quarter, PharmAust also achieved a positive outcome in a veterinary phase II clinical trial investigating the effects of monepantel oral tablets on canines with treatment-naïve B-cell lymphoma – the most commonly-treated cancer in dogs.
The trial aimed to assess the drug’s efficacy as a first-line therapy in dogs with the lymphoma which had not received any previous chemotherapy.
Investigators observed a 100% survival rate during the trial where typically 50% of untreated dogs would not survive beyond 28 days.
One dog achieved a greater than 60% reduction in tumour burden, with one of its tumours completely disappearing within 14 days.
PharmAust Chief scientific officer Dr Richard Mollard said the outcome provided a “meaningful trend”, comparing favourably with results of a 2017 canine trial using the original liquid monepantel formula.
“We had a number of key goals for this trial – determining the safety and efficacy of the tablets; evaluating delivery capabilities of the newly-developed monepantel tablets; and gathering sufficient positive and indicative data to enable phase III trials,” he said.
“We consider that all these goals have been met.”
Earlier this month, PharmAust confirmed the final report from the phase II canine trial had been delivered, providing the opportunity for the US$9 billion NASDAQ-listed Elanco US Inc to activate a six-month exclusive option over licencing of the drug for veterinary uses.
Dr Mollard said PharmAust was making good progress towards the evaluation of monepantel in human trials.
The company has conducted further tablet formulation and pharmacokinetic studies with the aim of increasing the uptake of monepantel into the bloodstream and reducing tablet numbers for future human trials.
“We currently have two batches of GMP-grade monepantel under stability studies testing the shelf-life of the formulation,” he said.
“These studies show a robust tablet and [we will use this] to support relevant submission filings to human trial ethics committees.”
PharmAust has scheduled a third GMP manufacture program for monepantel tablets later this year to cater for the planned human trials.
It is also seeking a suitable venue in which to conduct the phase II human trials to complement a phase I trial undertaken at the Royal Adelaide Hospital in 2015.
PharmAust’s wholly-owned subsidiary Epichem finished the 2020 financial year in a strong position, achieving revenue of $3.54 million and exceeding the $3.32 million forecast.
The synthetic and medicinal chemistry provider was acknowledged as the only company of its kind to continue to provide services during the COVID-19 pandemic as many other partners were more seriously impacted and affected.
Its chemistry-grade hand sanitiser was donated to healthcare and aged care providers in need during the lockdown period, with beneficiaries including not-for-profit partners such as the Cancer Council.
Epichem supports PharmAust’s drug development pipeline with lead drug development and validation, drug candidate pipeline manufacture and analysis, drug reformulation, GMP synthesis and stability support as well as drug inventory dispensing to clinical trial centres.
It is also involved in a series of government-run projects including the Smart Surface Chemistry Taskforce chaired by former Australian of the Year Dr Fiona Wood.
The taskforce aims to keep WA’s community safe through the use of multi-purpose initiatives relating to cleaning and sanitisation to slow the spread of COVID-19.