Redpin bags A round to advance Chantix-controlled gene therapies

Redpin Therapeutics has raised $15.5 million to bankroll chemogenetic R&D. The initial close of the series A positions Redpin to move a controllable gene therapy for the treatment of indications such as epilepsy and pain toward an IND.

New York-based Redpin is a gene therapy company with a difference. Like its peers, Redpin uses viral vectors to introduce genes into patients. Yet, while for traditional gene therapy companies that is the end of the process, for Redpin it is just the start. The genes inserted by Redpin encode for engineered ion channel proteins designed to bind to a particular drug, namely Pfizer’s Chantix.

When the patient takes Chantix, the molecule binds to the the ion channels now expressed by the neurons, either stimulating or silencing the cells based on what is needed to treat the disease they cause. As Redpin CEO Elma Hawkins notes, the approach differs from traditional drug development.

“We sort of the do the opposite of what has been done in the pharmaceutical industry for decades and decades. Instead of making small molecules for a biologic target or receptor, we pick a drug and then we make a very, very specific receptor for it. As long as these two molecules, the receptor and the small molecule, engage, you will have an effect on the neuron,” Hawkins said. 

The approach could enable very direct control over cellular activities. And, as the inserted gene only has a therapeutic effect in the presence of Chantix, the approach could allow physicians to effectively turn the gene therapy on and off.

That potential has caught the attention of investors. 4BIO Capital, an advanced therapy specialist that raised a $50 million fund last year, led the round with Arkin Bio Ventures. The VC wing of Takeda also chipped in cash as did seed round investors New York Ventures and Alexandria Venture Investments.

Having spent the past year amassing preclinical data, Redpin will use the money to push toward an IND, although at this time the biotech is yet to commit to a timeline for getting into the clinic. Redpin has been more forthcoming about the broad focus of its lead program, which is designed for use in conditions such as pain and epilepsy that are characterized by hyperexcited neurons. 

“If you have a therapy that can 'calm that down,' that would be a terrific solution as you’re acting at the site of the problem,” Hawkins said. Redpin could equally use the same basic approach to activate neurons, opening up another set of indications that are potentially amenable to treatment using its Chantix-controlled gene therapies.  

Whatever the goal, the basic idea is to design and introduce receptors that bind to Chantix. The oral drug, which Pfizer sells to help smokers quit, became integral to Redpin’s approach in part because it penetrates the brain effectively and is well tolerated at the low doses needed for the gene therapy application.