According to a press release issued on Wednesday, Turing Pharmaceuticals will be pushing several new drug candidates for toxoplasmosis into preclinical development. The company says the small molecular compounds are a result of Turing’s toxoplasmosis research efforts, with the drug candidates reportedly offering improved potency and specificity over currently-available treatments, in animal models.
Turing reports that it has started safety studies for the compounds in support of an eventual filing of an Investigational New Drug Application (IND), as part of the US Food and Drug Administration’s (FDA) drug approval process. According to a statement, the company anticipates that clinical trials for the experimental drugs will begin in the second half of 2017.
“There’s a definitive need for new and improved therapies against toxoplasmosis,” said Dr. Eliseo Salinas, Turing’s President of R&D. “Current therapies target a protein family that is required by both the parasite and its human host. Consequently, treating physicians are limited in the doses of the current products they can use to eliminate the parasite. The ability to selectively engage the parasite would maximize the opportunity to eliminate infection without harming the patient.”
Toxoplasmosis is caused by a common parasite – known as Toxoplasma gondii – which is present in about one fifth of the US population. While most cases are asymptomatic, those with compromised immune systems could have serious, potentially fatal reactions to the infection.
There have been little advances in the treatment of toxoplasmosis in the past half-century. Pyrimethamine – sold under the trade name Daraprim – was approved in 1953 and is still used by patients today.
Turing’s research efforts have largely focused on the development of dihydrofolate reductase (DHFR) inhibitors, which stop the action of an enzyme responsible for folate metabolism and cell division. Currently-available treatments which target this pathway are effective against the toxoplasmosis parasite, but also trigger unintended effects on the equivalent enzyme found in human cells.
To discover new drug candidates with improved selectivity, Turing employed computational chemistry, in silico screening, structure-based drug design and in vivo testing of the most promising candidates. Turing’s more selective compounds could eliminate some of the side effects inherent in current toxoplasmosis treatments, and expand the number of patients who could benefit from the treatment.
The company is most likely hoping this week’s announcement will go a long way to improving Turing’s public image. Turing’s former CEO, Martin Shkreli, made headlines last year when he raised the price of Daraprim by over 5,000 percent.