FDA clears Roche's Enspryng for thyroid eye disease

 Roche has claimed US approval for IL-6 receptor antagonist Enspryng in a second indication – thyroid eye disease (TED) – that furthers its ambition to grow the drug into a blockbuster product.

The first-in-class drug joins Amgen's IGF-1 receptor antagonist Tepezza (teprotumumab) and Viridian Therapeutics' similarly acting Lumvoa (veligrotug) among FDA-approved therapies for TED, a rare autoimmune disorder that results in bulging eyes (proptosis), visual disturbances, pain, and inflammation.

Enspryng (satralizumab) has been approved for the rare eye disorder neuromyelitis optica spectrum disorder (NMOSD) since 2020, and brought in sales of $237 million for Roche in the first half of this year. The company has said that additional indications could drive the product over the $1 billion annual sales threshold as early as 2027.

Along with the approval in TED, it has also filed Enspryng for FDA approval in another rare condition – myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), which attacks the optic nerves, spinal cord, or brain – with a decision due in January. Other future indications could include autoimmune encephalitis (AIE) and Duchenne muscular dystrophy (DMD), depending on trial results.

Roche has high hopes for Enspryng in TED, as it is the first treatment for the condition that patients can administer subcutaneously at home using a prefilled syringe or pen injector. At the moment, both Tepezza and Lumvoa require intravenous infusions in a clinic.

That said, Amgen has phase 3 results for a new, subcutaneous formulation delivered using an on-body injector (OBI) device, while Viridian is developing a subcutaneous alternative, elegrobart, which is scheduled for filing in the US early next year.

"Treating thyroid eye disease requires balancing efficacy, safety, and the practical realities of long-term treatment," said César Briceño, of the Scheie Eye Institute at the University of Pennsylvania, who was an investigator in Roche's trials of Enspryng in TED.

"The availability of an effective subcutaneous treatment option could provide greater flexibility for both patients and physicians while reducing the logistical burden associated with infusion-based therapies," he added.

Enspryng achieved mixed responses in the phase 3 SatraGO-1 and SatraGO-2 studies, with only the latter meeting its primary efficacy endpoint, a response in proptosis, which was achieved in 52.9% of the active treatment group and 23.4% of patients receiving placebo.

Despite the disappointing result in SatraGO-1, Roche maintained that the totality of the data showed "clinically meaningful" improvements in patients with TED, including in other efficacy measures like double vision, and the FDA has sided with that interpretation of the data.

Analysts have estimated that the TED indication alone could be worth $500 million to $1 billion in peak annual sales for Roche. For comparison, Tepezza made more than $1 billion for Amgen in the first half of the year.

https://pharmaphorum.com/news/fda-clears-roches-enspryng-thyroid-eye-disease