Biotech drug developer Noxopharm (ASX: NOX) has revealed new data confirming idronoxil, the active ingredient in the company’s experimental anti-cancer drug Veyonda, as a new immuno-oncology drug that could help boost the effect of cancer treatments.
The company today released data from the first series of pre-clinical studies involving human cell and animal test systems, which confirmed that idronoxil activates the immune system, increasing functional natural killer (NK) cells and CD4+ (T-helper) cell numbers.
These are types of white blood cells that play important roles in the body’s natural ability to attack and reject tumours and infections.
According to Noxopharm, this data has identified idronoxil as a new class of immuno-oncology drug, that is, a drug that seeks to help the body’s own immune system fight cancer.
Noxopharm chief executive officer Greg van Wyk said it means the company’s anti-cancer drug candidate Veyonda appears to be “truly versatile … with these immune-oncology effects having the potential to complement its radio-enhancing and chemo-enhancing functions across a broad range of cancer types”.
Essentially, the discovery means Veyonda could have the potential to boost the effect of radiation and chemotherapy treatments in fighting cancer.
According to the company, it also positions the drug as a potential means of overcoming the restricted benefits of the current standard immuno-oncology drugs. These current standard drugs are checkpoint inhibitors, which block proteins that stop the immune system from attacking cancer cells.
“These drugs have proven to be limited in their effectiveness, providing benefit only in selected cancers such as lung cancer, melanoma, bladder cancer, head and neck cancer and Hodgkin’s lymphoma,” Noxopharm stated.
Furthermore, the company said only about 20-25% of patients with these cancer types typically respond to these checkpoint inhibitor drugs, leaving the majority of patients across the entire cancer spectrum deriving little or no benefit at all.
Noxopharm said finding ways to extend the benefit of current immuno-oncology drugs to most cancer patients is a “major goal in the global pharmaceutical sector”, with extending the activation to the innate immune system (NK and CD4+ cells) being of particular research interest.
“The studies reported on today confirm that idronoxil modulates cells associated with both arms (adaptive and innate) of the immune system, which the company believes positions Veyonda in the vanguard of this global effort,” it stated.
“This exciting discovery supports our strategy of combining Veyonda with radiotherapy or chemotherapy, as engaging the immune system to enhance the effect of these treatments has seen a revolution in cancer care in recent years,” Mr van Wyk added.
In 2017, the global immune checkpoint inhibitor market was valued at US$10.5 billion (A$14.68 billion), according to Noxopharm. The company said if the response rate of these drugs was lifted by even 10% above current use, this would represent a “major breakthrough” and “expanding responsiveness to additional cancer types could be expected to expand the market considerably”.
Noxopharm has a three-pronged clinical strategy of studying Veyonda in combination with chemotherapy, external beam radiotherapy (its DAART program) and intravenous radiopharmaceuticals (the LuPIN program).
Last week, the company announced it would be expanding its chemotherapy enhancement program after the final report from a phase 1b study revealed positive efficacy signals in late-stage cancers.
This followed recent positive data emerging from the company’s DAART-1 study, which recorded “clinical benefits” in treating late-stage prostate cancer patients with a combination of Veyonda and radiotherapy, as well as progress being made in the LuPIN trial.
Following the company’s latest discovery, Noxopharm said it wants to combine Veyonda with a standard checkpoint inhibitor with the aim of achieving a more potent immuno-oncology effect in cancers that are currently targeted by these checkpoint inhibitors, as well as a strong effect in common cancer types like breast and prostate cancer which are currently not being targeted.
“The most appropriate way to incorporate a current checkpoint inhibitor into the current clinical program is under current consideration,” Noxopharm stated.