Santhera bags DMD drug in 3-way deal with Idorsia and ReveraGen

Santhera has exercised its option on non-hormonal steroid modulator vamorolone, giving it control of a Duchenne muscular dystrophy (DMD) asset it thinks can rack up annual sales of more than $500 million.

ReveraGen took vamorolone into the clinic in the belief it can preserve muscle function and prolong ambulation without causing the growth stunting and immune suppression associated with the use of corticosteroids. The potential of the drug attracted Actelion, which picked up an option on it in 2016. Two years later, Actelion, by then reborn as Idorsia, changed its plans, leading it to sell the option to Santhera Pharmaceuticals.

The agreement allowed Santhera to wait until the receipt of phase 2b data before deciding whether to exercise its option. However, Santhera has pulled the trigger ahead of time, agreeing to revised agreements with Idorsia and ReveraGen that give it worldwide rights to vamorolone in DMD and all other indications.

Santhera is giving Idorsia some shares and a CHF 10 million ($11 million) exchangeable note, and is set to pay ReveraGen $7 million in monthly installments of up to $500,000. Idorsia and ReveraGen are in line to pocket more cash as vamorolone advances. 

Under the terms of the 2018 deal with Idorsia, Santhera would have needed to pay Idorsia $30 million to exercise its option and commit to milestones that could total hundreds of millions of dollars. The new deal features smaller milestones. For example, the amount Santhera could pay Idorsia up to and including FDA approval has fallen 20% to $72 million. 

In a statement to explain the decision to exercise the option now, Santhera CEO Dario Eklund cited “enhanced deal terms and the ability to gain full control over the asset” as motivating factors. Having struck the deal, Santhera is now in a position to grant sublicenses and claim a 10% share of proceeds generated by the sale of a Priority Review Voucher the FDA may award if it approves vamorolone.

The deal leaves Santhera with two late-stage DMD assets. In addition to vamorolone, Santhera has Puldysa, a DMD prospect that was closing in on a conditional authorization decision in Europe until the company asked to pause the process. Santhera is using the extra time to evaluate the possibility of including data from a U.S. study in the submission.