Sonnet bags ex-Serono neuropathy drug via Relief Therapeutics deal

Sonnet BioTherapeutics has struck a deal to acquire an ex-Serono drug from Relief Therapeutics. The agreement tees Sonnet up to advance the asset in chemotherapy-induced peripheral neuropathy (CIPN) using an equity facility worth up to $100 million (€89 million).

Relief picked up the molecule, a low-dosage IL-6 formulation called atexakin alfa, from Merck KGaA in 2015. By that time, the asset had gone through phase 1/2 trials in thrombocytopenic cancer patients only to be deemed surplus to requirements at Merck KGaA. Relief planned to get the project moving again by advancing the candidate into a midphase diabetic neuropathy trial. 

In April, Relief took a write-down on the value of the subsidiary that is primarily focused on atexakin and revealed it had entered into a letter of intent with Enterosys to explore the potential of the drug in other indications.

Now, Relief has offloaded atexakin and the subsidiary that is developing it. The deal sees Relief divest the subsidiary to Sonnet in return for 7.1 million shares in the privately held, New Jersey-based biotech.

Sonnet plans to take the drug forward in CIPN and has high hopes for the program.

“We believe atexakin has the potential to be a safe and effective treatment for CIPN, where there are currently no approved disease modifying therapies,” Pankaj Mohan, chairman of Sonnet, said in a statement. “Owing to the size of the patient population and corresponding high unmet medical need, we see atexakin as having the potential to eventually become a blockbuster product.”  

The statement to disclose the news said Sonnet has access “to a certain common stock purchase agreement, implementing an equity facility of up to $100 million” through an “experienced investor.” Sonnet plans to use the money, plus other sources of funding it is pursuing, to progress atexakin.