Biogen’s Non-Opioid Pain Drug Shines in Small Fiber Neuropathy Study

 

Biogen reported positive topline results from its Phase II CONVEY trial of vixotrigine for treatment of small fiber neuropathy (SFN). 

Vixotrigine is an oral non-opioid pain medication. It is a voltage- and use-dependent voltage-gated sodium channel blocker. Sodium channels have a significant role in conducting nerve impulses, including in pain-sensitive neurons that respond to tissue damage.

The CONVEY trial’s 200 mg twice-a-day arm hit the primary endpoint of change from baseline to week 12 of the double-blind period in mean average daily pain (ADP) score. All people who enrolled received the higher dose, 350 mg twice a day, in an open-label part that went ahead of the double-blind part of the trial. 

The 350 mg twice-daily arm did not meet the primary endpoint, although it had statistical significance in the Patient Global Impression of Change (PGIC) at week 12. The company indicates that the overall data from the vixotrigine program will help them determine dose levels for future Phase III trials.

Small fiber neuropathy is often marked by severe pain that starts in the hands or feet. The symptoms are described as burning, shooting and/or prickling. The pain can be caused by stimuli that don’t normally cause pain, and the stimuli can increase in intensity. 

Symptoms are often worse at night and during rest periods. It is characterized by the degeneration of small-diameter sensory fibers and can occur on its own or be associated with disorders such as diabetes, infections, immune diseases, or toxicity. The most common causes are diabetes and impaired glucose intolerance.

“We are encouraged by the overall results of the CONVEY study, especially given the significant unmet need for additional agents to treat chronic painful neuropathy,” said Katherine Dawson, Senior Vice President, and Head of the Therapeutics Development Unit at Biogen. “We are grateful to all the participants, investigators and study staff who contributed to this study and allowed us to evaluate vixotrigine as a non-opioid treatment option for people living with chronic neuropathic pain due to small fiber neuropathy.”

Yesterday, Biogen announced plans to launch a global Phase IIIb ASCEND trial. It will study a higher dose of Spinraza (nusinersen) in children, teens and adults with later-onset spinal muscular atrophy (SMA) after treatment with Roche’s Evrysdi (risdiplam). 

“We believe that lower drug exposure may be contributing to less-than-optimal treatment outcomes for some patients treated with Evrysdi,” said Maha Radhakrishnan, Chief Medical Officer at Biogen. “The ASCEND study seeks to understand if nusinersen may address that unmet medical need and will help inform the future of SMA treatment, with the hope of improving patients’ outcomes for the long term.”

SMA is a rare, genetic, neuromuscular disorder affecting people of all ages. It is marked by a loss of motor neurons in the spinal cord and lower brain stem. This causes progressive muscle atrophy and weakness. The disease is caused by a deficiency in the production of survival motor neuron (SMN) protein as the result of the damaged or missing SMN1 gene. It affects about 1 in 11,000 live births and is a leading cause of genetic death among infants.

Evrysdi’s maximum dose is 5 mg once patients hit 20 kilograms in weight. Biogen says the data suggests that patients’ exposure to the drug decreases as they grow, and that leads to less successful treatment. The new study will enroll up to 135 patients. Biogen is already evaluating a higher dose of Spinraza in the DEVOTE trial.

Biogen’s Spinraza faces competition from Roche’s Evrysdi as well as Novartis’ gene therapy Zolgensma. Roche’s drug can be taken orally, while Spinraza is an intrathecal injection requiring a visit to a specific treatment center.