On September 28th, the FDA approved Emcitate, or tiratricol, from Egetis Therapeutics. It’s the first-ever treatment for MCT8 deficiency, a condition also known as Allan-Herndon-Dudley syndrome.
MCT8 deficiency is a rare genetic disorder that mostly affects boys because the gene is on the X chromosome. The gene here makes a transporter protein called MCT8, which carries thyroid hormone into cells. When that transporter doesn’t work, it creates two problems. One is central, and one is peripheral. On the central side, the brain is starved of thyroid hormone, and this leads to numerous developmental concerns. On the peripheral side, excess thyroid hormone builds up in the bloodstream and can be toxic, creating chronic stress on the heart and metabolism.
Emcitate lowers excess thyroid hormone circulating in the blood, which is what this approval targets: peripheral toxicity. The FDA based its decision on two studies that showed reductions in excess thyroid hormone levels in the blood, along with improvements in heart rate and blood pressure.
Emcitate received five major FDA designations, including orphan drug, rare pediatric disease, fast track, breakthrough therapy, and priority review. That’s a pretty strong signal of how seriously the FDA viewed this condition.
On September 25th, the FDA approved Gazyva, or obinutuzumab, from Genentech to reduce the risk of relapse in patients ages 2 years and older with frequently relapsing or steroid-dependent childhood-onset idiopathic nephrotic syndrome who are in complete remission. Genentech is calling it the first FDA-approved treatment option for this condition in 70 years.
Nephrotic syndrome happens when the kidney’s filter starts leaking large amounts of protein into the urine. As protein is lost, albumin levels in the blood drop, fluid shifts into the tissues, and patients develop swelling, often first around the eyes and in the legs. They also have high cholesterol and a higher risk of infections and blood clots.
Steroids are the first-line treatment and usually work, but more than 70% of patients relapse, and long term use of steroids has its own set of problems.
Gazyva is a monoclonal antibody that targets CD20 on B cells. In the Phase 3 INShore study, 95 percent of patients on Gazyva stayed in complete remission without relapse through week 52.
Gazyva actually started in blood cancers, where it targets B cells. Then it moved into lupus nephritis, and now it’s approved for another kidney disease. So we’re seeing Gazyva move from cancer into autoimmune diseases.
And Genentech isn’t stopping there. It’s studying Gazyva in other disorders. So once a drug proves it can target a particular mechanism, companies can look for other diseases where that same approach might work.
The Myasthenia Gravis Foundation of America held its 2026 Scientific Session on September 29th in Orlando, alongside the AANEM Annual Meeting. And industry showed up in force for myasthenia gravis: Johnson & Johnson had 26 abstracts, argenx had 18, Alexion and AstraZeneca had 15, UCB had 5, and Amgen had 2.
Myasthenia gravis is an autoimmune disease in which a person’s own antibodies attack the junction where nerves signal muscles to contract, most often by targeting the acetylcholine receptor.
Myasthenia gravis is also a great model for studying autoimmune diseases. Researchers have a better understanding of the pathophysiology, the chain of events that creates these immune overreactions, and how to measure outcomes reliably.
Right now there are three main approaches for myasthenia gravis. The first is FcRn blockers. The second is complement inhibitors. The third approach goes further upstream and targets the B cells that make the antibodies. So you have drugs that remove the antibodies, drugs that block the damage they cause, and drugs that reduce their production.
None target the ACHR antibody exactly, but they do target the immune system that produces those autoantibodies. And that knowledge is transferable to other autoimmune conditions, ones that are not as fully understood as myasthenia gravis.
For patients with other rare autoimmune diseases, that’s encouraging. A therapy developed and validated in one disease may ultimately give researchers a faster path to treating another.
References
FDA Approves First Treatment for MCT8 Deficiency
https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-mct8-deficiency
FDA Approves Gazyva for Idiopathic Nephrotic Syndrome in Patients Aged 2 and Older
https://www.gene.com/media/statements/ps_092526
2026 MGFA Scientific Session
https://myasthenia.org/events/2026-scientific-session/
FDA Approves Uplizna for the Treatment of Generalized Myasthenia Gravis
https://checkrare.com/fda-approves-uplizna-for-the-treatment-of-generalized-myasthenia-gravis/