Roche’s IL-6 Blocker Clears Phase III Bar, Still Falls Short of Expectations

Roche China_iStock, Robert Way

Pictured: Roche's building in Shanghai, China/iStock, Robert Way

Roche subsidiary Chugai Pharmaceutical on Thursday unveiled results from the Phase III LUMINESCE study, showing that its IL-6 inhibitor Enspryng (satralizumab) could significantly improve generalized myasthenia gravis symptoms that affect daily life.

However, the biotech was unsatisfied with the magnitude of Enspryng’s effects, noting in the announcement that “the results did not reach our expectations on the degree of clinical benefit.”

In terms of safety, LUMINESCE found that Enspryng was well-tolerated when used to treat generalized myasthenia gravis (gMG), with an adverse event profile that was consistent with what had been established in trials in neuromyelitis optica spectrum disorder (NMOSD).

Roche and Chugai did not provide specific data in their announcement but promised to present detailed results at the upcoming American Academy of Neurology Annual Meeting on April 15 in Denver, Colorado.

The companies also did not detail their future plans for Enspryng in gMG, a chronic autoimmune disorder in which antibodies destroy communication between nerves and muscle, causing weakness of the skeletal muscles.

Designed to be delivered via subcutaneous Injections, Enspryng is a recombinant humanized monoclonal antibody that targets the IL-6 cytokine. According to its label, Enspryng’s exact mechanism of action is still unknown, though it is thought to Interfere with IL-6 signaling and the inflammatory cascade.

Enspryng won the FDA’s approval in August 2020 for the treatment of NMOSD patients positive for the aquaporin-4 antibody. Thursday’s readout does not affect Enspryng’s approval in NMOSD, according to the companies’ announcement.

Roche and Chugai will also continue to develop Enspryng in other inflammatory and neurological autoimmune indications, including myelin oligodendrocyte glycoprotein-associated disorder, thyroid eye disease and autoimmune encephalitis.

LUMINESCE’s disappointing data buck Roche’s clinical winning streak in recent months. Last week, the pharma announced during a neurology-focused investor event that its investigational Alzheimer’s disease therapy trontinemab cleared a Phase Ib/II study, demonstrating rapid and robust reduction in amyloid plaque levels.

Trontinemab, developed using Roche’s proprietary Brainshuttle technology, penetrates the blood-brain barrier reaching high levels of distribution throughout the central nervous system.

Earlier this month, Roche’s Alnylam-partnered RNAi therapeutic zilbesiran aced its Phase II study, eliciting a significant drop in 24-hour mean systolic blood pressure.

Roche also recently reported several Phase III victories, including one for its asthma drug Xolair (omalizumab) in food allergies and its anti-TIGIT immunotherapy tiragolumab in esophageal squamous cell carcinoma. In December 2023, the pharma announced that its orally available PI3Kα inhibitor inavolisib significantly improved progression-free survival in PIK3CA-mutated, HER2-negative breast cancer when used with palbociclib and fulvestrant in the first-line setting.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at tristan@tristanmanalac.com or tristan.manalac@biospace.com.

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