After 35 years of mediocre depression drugs, pharmaceutical companies are jazzed about several new drugs inspired by the club drug ketamine.

Allergan, the multinational pharmaceutical giant known for Botox and birth control, recently dove into research on an injectable depression drug called Rapastinel.

Most recently, the company announced it was working on oral pill version of that drug.



After nearly four decades of dispensing the same mediocre medications to patients with depression, pharmaceutical companies are jazzed about several new drug candidates inspired by the club drug ketamine.

Allergan, the multinational pharmaceutical giant known for Botox and birth control, recently dove deep into research on an injectable depression drug called Rapastinel, which works on the same brain pathway as ketamine.

The company plans to file for approval with the Food and Drug Administration within two years. Last week, Allergan also announced plans to go after an oral pill formulation of Rapastinel that would be easier to take and more widely used.

The development "points to the general air of excitement in this area," C. David Nicholson, Allergan's chief of research and development, told Business Insider.

Allergan isn't the only pharmaceutical company that is hot on the trail of new depression drugs inspired by ketamine. Johnson & Johnson is pursuing esketamine, the chemical mirror image of the drug, in a nasal spray formula.

After publishing positive clinical trial results earlier this month, the company told Business Insider it planned to file for FDA approval of the drug this year. VistaGen, a small San Francisco-based drug company, is studying a drug similar to Allergan's Rapastinel called AV-101.

All of those efforts hint that a new blockbuster depression drug could be just around the corner — all thanks to a club drug once known chiefly as "Special K."

A reawakening for new depression drugs inspired by ketamine

Scientists recently called ketamine, a drug most people know either as a surgical anesthetic or a party drug, "the most important discovery in half a century." The drug landed on researchers' radar after swiftly lancing depressive symptoms in people — including suicidal patients — with some of the hardest-to-treat forms of the disease.

But ketamine is difficult to give patients (it's generally administered via an IV drip over roughly 45 minutes) and does have some negative side effects (many people describe a dissociative, quasi-psychedelic sensation of floating outside of their body, for example). Ketamine is also expensive, and most insurance providers don't cover it.

Drug companies are looking for candidates that mirror ketamine's positive qualities while minimizing its negative side effects. Injectable drug candidate Rapastinel could be Allergan's answer to this quandary.

"Now that ketamine has shown improvements in depression, it has reawoken interest in this area. And Rapastinel appears to combine the best of all worlds in terms of efficacy and safety," Nicholson said. "I believe it will be a breakthrough and will be used extensively."

But despite showing hugely positive results in clinical trials so far, Rapastinel still faces one road block: it's a shot, and people don't like shots.

So while Rapastinel moves through the drug approval process, Allergan is also eyeing an oral pill formula which would hopefully either mimic or at least complement Rapastinel's effects. If successful in clinical trials, the pill could also be used "more widely" than Rapastinel, Nicholson said.

'As soon as there's a breakthrough all those other companies that dropped out will want back in'

For now, Allergan's new oral pill depression drug candidate is known only as AGN-241751. Like Rapastinel, AGN-241751 was initially developed by a company called Aptinyx. In 2015, as part of a $560 million deal with the company, Allergan nabbed the rights to develop and commercialize both drugs.

The deal sheds light on Allergan's renewed strategic focus on new neuroscience drugs, Nicholson said. In the past, the drugmaker has worked on medications designed to treat migraines, Parkinson's, and Alzheimer's; depression is the latest arm of that research focus.

Nicholson also believes that the interest he's seeing in ketamine-inspired drugs could be the breakthrough needed to stir-up renewed interest among drugmakers in the neuroscience field, which declined somewhat after several promising Alzheimer's drug candidates failed to turn into treatments.

"We see a great future in neuroscience research and development. These things tend to go through cycles. There’s a breakthrough, and Rapastinel hopefully will be one of those breakthroughs. And as soon as there’s a breakthrough all those other companies that dropped out will want back in."