WASHINGTON, DC — When you talk to Viralytics CEO Malcolm McColl, he has a habit of reminding his listeners about just how small his public Australian biotech is. Small staff, small studies. And there are just so many things a small biotech can do.
Malcolm McColl
But he and his company {ASX: VLA} have some very big ambitions in the hot oncolytics field, building their hopes around a therapy called Coxsackievirus A21 (or CVA21 or Cavatak). And today the powers that be at AACR are steering their latest data into the showcase morning round.
At the time of the data cutoff for AACR, the company had evaluable responses from 22 patients in a small melanoma study combining their therapy — using a nongenetically altered cold virus to infect cancer cells, designed to destroy them and recruit T cells for a followup attack — with Yervoy.
Injected directly into lesions, researchers tracked an overall response rate of 50%, with 4 patients registering a complete response and 7 patients experiencing a partial response. The median duration of response was not yet reached, “with a number of responses greater than six months and several still ongoing” — a signal of potential durability.
Among 11 patients who had disease progression following earlier treatment with an immune checkpoint inhibitor, 4 had a response. The other 7 responders had not been treated earlier with a checkpoint.
“The preliminary overall response rate of 50% is very positive because previous reports indicate an 11% overall response rate for ipilimumab alone and an approximately 28% overall response rate for CVA21 alone,” said Brendan Curti, the primary investigator who runs a melanoma clinic in Portland.
The safety profile also looked good. Of 25 patients who could be evaluated for safety, two had grade 3 or higher ipilimumab-related adverse events. No CVA21-related adverse events of grade 3 or higher were reported.
The next step, says McColl, will be to add several dozen patients to the study who have failed a checkpoint therapy and then see if they have the kind of results that can be used to mount a registration study.
It’s conceivable, he says, that regulators could sign off on a single arm study with a couple of hundred patients for that pivotal try, that’s “something a small Australian company could take on.”
Viralytics has jumped on to a stage that includes a growing number of oncolytics players, like PsiOxus, which recently signed a standout $936 million deal to partner with Bristol-Myers, which was already helping with a combo of Opdivo plus their oncolytic virus.
All these companies are coming in behind Amgen’s T-Vec, the pioneering drug in the field which they believe is ripe for surpassing its results in the clinic.
So far, McColl’s small Australian company has paid the freight on the work, with Merck providing Keytruda for combinations in the clinic. At some point, if things continue to progress, McColl also expects to strike a money/marketing deal.
“I don’t think a small Australian company will be marketing a drug in the US,” he says with a smile. After today, he might find a few new opportunities on that score.
