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The Future of Anti-NMDAR Encephalitis Treatment: Exploring the ExTINGUISH Clinical Trial

The Future of Anti-NMDAR Encephalitis Treatment: Exploring the ExTINGUISH Clinical Trial

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April 10, 2024 | by Khashayar Eshaghi, PennNeuroKnow and IAES Collaboration

A message from IAES Blog Staff:

The staff at IAES is proud to present to all of you another wonderful article/blog from the amazing team at PennNeuroKnow. Since 2019 IAES has been extremely lucky to be in partnership with the PennNeuroKnow(PNK) team to help us all better understand complex medical issues related to AE and neurology in general. The talented PNK team continues to keep us up-to-date and help clarify the complexities we face each day along our AE journey, and we are eternally grateful! You can find out much more about this stellar group at: https://pennneuroknow.com/

—-

Introduction

You may have heard of current clinical trials striving to uncover new treatments for autoimmune encephalitis (AE). An exciting trial to look out for is the ExTINGUISH Trial — a promising clinical study in this field.

The Extinguish trial is set to evaluate the use of a monoclonal antibody in the treatment of anti-NMDAR Encephalitis, which is a subtype of AE. Recent successes in employing monoclonal antibodies, notably in treating complex neurological conditions like Alzheimer’s disease1, emphasize the potential breakthrough that this trial could signify.

The main goal of the ExTINGUISH trial is to assess the effectiveness of a specific monoclonal antibody, known as inebilizumab, in treating anti-NMDAR encephalitis2. Monoclonal antibodies are routinely utilized in the treatment of AE. However, the goal of researchers is to continue to make this technology better and more effective for patients.

What is inebilizumab?

In patients with autoimmune encephalitis, the body’s immune system mistakenly attacks the brain, causing inflammation. Inflammation causes the immune system to produce a kind of protein called an antibody. Typically, these antibodies flag things like invading viruses or bacteria for the immune system to find and destroy. In AE, antibodies play a harmful role by mistakenly flagging brain cells. As the immune system attacks the brain, patients with AE develop a host of symptoms, like seizures, mood changes, altered mental status, and memory loss3.

In an attempt to alleviate the symptoms of AE, scientists have long been interested in designing a drug that would prevent the immune system from making harmful antibodies. Recent research suggests that the best approach might be to fight fire with fire: by engineering a monoclonal antibody that specifically targets the immune cells responsible for generating the harmful antibodies at the onset of AE4. A monoclonal antibody is a special kind of protein created in a lab that can target and attach to specific harmful substances or cells in the body, helping the immune system to identify and neutralize them (figure 1).

monoclonal antibodies - The Future of Anti-NMDAR Encephalitis Treatment: Exploring the ExTINGUISH Clinical Trial

Figure 1. Monoclonal antibodies serve to assist the immune system in neutralizing cells responsible for producing detrimental antibodies in AE.

 

A new monoclonal antibody called inebilizumab has shown promise as a potential treatment for a subtype of AE, called anti-NMDAR encephalitis5.

Inebilizumab was recently approved for the treatment of neuromyelitis optica spectrum disorder (NMOSD), a rare autoimmune disorder affecting the central nervous system.

The fact that this monoclonal antibody is proving effective for patients with another autoimmune neurological disorder suggests it could work for AE as well6.

How is inebilizumab different from current monoclonal antibody treatments for anti-NMDAR Encephalitis ?

Another monoclonal antibody called rituximab is already a secondary treatment option for anti-NMDAR encephalitis that is used when first-line therapies fail or produce an adequate response7. Rituximab works by targeting one group of immune cells making the harmful antibodies in AE, called B cells. While rituximab can help manage anti-NMDAR encephalitis for some patients by getting rid of B cells, it does not work for everyone7. This could be because B cells live for a short time, but produce other longer-lived versions of themselves, called plasma cells and plasmablasts.

Moreover, monoclonal antibodies work by recognizing a specific marker on the cells that they aim to neutralize. For instance, rituximab targets all cells that express a specific marker called CD20 on their surface. While rituximab removes the B cells that express CD20, it leaves the plasma cells and plasmablasts in the body because they often lack the CD20 surface marker. Therefore, these long-lasting immune cells can continue to produce the problematic antibodies that lead to anti-NMDAR encephalitis8.

This is where inebilizumab comes into play. Inebilizumab targets a different surface marker called CD19. This marker is not only expressed by B cells, but it is also present on the surface of their longer-lasting progeny, the plasma cells and plasmablasts. Therefore, by targeting all cells that express CD19 inebilizumab is capable of neutralizing the original B cells as well as the longer-lasting plasma cells and plasmablasts (figure 2)8.

Screenshot 2024 04 09 at 8.52.58 AM - The Future of Anti-NMDAR Encephalitis Treatment: Exploring the ExTINGUISH Clinical Trial

Figure 2. Inebilizumab inhibits the production of plasma cells and plasmablasts that produce harmful antibodies against the brain.

By getting rid of more of the immune cells producing harmful antibodies against the brain, inebilizumab may be an even more effective treatment for anti-NMDA encephalitis than rituximab8,9.

The ongoing clinical trial

Clinical trials are scientific tests for new medications or treatments to determine if promising new treatments are more effective than what is currently on the market. In what are called placebo-controlled clinical trials, some participants get the new treatment, while others get a placebo. A placebo is a version of the treatment without the active ingredient of the medicine in it. This helps researchers compare how well the real treatment works by checking if there is a noticeable difference between those who get the medicine and those who get the placebo. It is a way to make sure the treatment is genuinely effective. Following the trial’s conclusion, should the new treatment prove effective, members of the placebo group will likewise be granted access to it.

The clinical trial for inebilizumab is called the ExTINGUISH Trial. The ExTINGUISH Trial aims to assess the effectiveness of inebilizumab compared to a placebo in treating moderate-to-severe NMDAR encephalitis alongside standard therapies. This trial involves 120 participants with moderate to severe anti-NMDAR encephalitis and evaluates patient outcomes using various measures that assess their daily functioning, brain abilities, quality of life, and predict how they may progress over a 16-week period. The study also aims to find biological markers that can be used to predict how well the treatment will work in future patients. Doctors and researchers will monitor levels of the anti-NMDAR antibodies responsible for the symptoms of AE as well as a measure of activation of the B cells that produce these harmful antibodies2,10. This will allow doctors to determine whether patients with certain levels of these substances in their body respond better or worse than others.

Ultimately, this trial aims to find more effective treatments for anti-NMDAR encephalitis, paving the way for improved care for individuals facing this condition. Looking ahead, these advancements in clinical trials offer hope for developing better treatments and understanding AE, potentially leading to breakthroughs in managing and preventing the disease in the future.

Additionally, while the current trial focuses on anti-NMDAR encephalitis, the insights gained from understanding the mechanisms of action and treatment response could potentially apply to other types of AE as well. While the immediate beneficiaries of this trial are individuals with anti-NMDAR encephalitis, the broader implications may extend to those with different forms of AE in the future, offering hope for improved treatment options and outcomes across various autoimmune encephalitis conditions.

References

  1. van Dyck, C. H., Swanson, C. J., Aisen, P., Bateman, R. J., Chen, C., Gee, M., Kanekiyo, M., Li, D., Reyderman, L., Cohen, S., Froelich, L., Katayama, S., Sabbagh, M., Vellas, B., Watson, D., Dhadda, S., Irizarry, M., Kramer, L. D., & Iwatsubo, T. (2023). Lecanemab in Early Alzheimer’s Disease. The New England journal of medicine, 388(1), 9–21. https://doi.org/10.1056/NEJMoa2212948
  2. Day, G., Titulaer, M., Wong, K.-H., Torner, J., Cudkowicz, M., Coffey, C., Lungu, C., Klawiter, E., Singleton, J. R., Mitchell, D., Fedler, J., Ecklund, D., Klements, D., Costigan, M., & Clardy, S. (2022). The extinguish trial: A phase-2b randomized placebo-controlled trial of inebilizumab in Anti-NMDA receptor encephalitis (P5-1.004). Neurology, 98(18_supplement). https://doi.org/10.1212/wnl.98.18_supplement.1651
  3. Hébert, J., Muccilli, A., Wennberg, R. A., & Tang-Wai, D. F. (2022). Autoimmune Encephalitis and Autoantibodies: A Review of Clinical Implications. The journal of applied laboratory medicine, 7(1), 81–98. https://doi.org/10.1093/jalm/jfab102
  4. Frampton J. E. (2020). Inebilizumab: First Approval. Drugs, 80(12), 1259–1264. https://doi.org/10.1007/s40265-020-01370-4
  5. Samanta D, Lui F. Anti-NMDAR Encephalitis. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK551672/
  6. Nie, T., & Blair, H. A. (2022). Inebilizumab: A Review in Neuromyelitis Optica Spectrum Disorder. CNS drugs, 36(10), 1133–1141. https://doi.org/10.1007/s40263-022-00949-7
  7. Smets, I., & Titulaer, M. J. (2022). Antibody Therapies in Autoimmune Encephalitis. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, 19(3), 823–831. https://doi.org/10.1007/s13311-021-01178-4
  8. Chen, D., Gallagher, S., Monson, N. L., Herbst, R., & Wang, Y. (2016). Inebilizumab, a B Cell-Depleting Anti-CD19 Antibody for the Treatment of Autoimmune Neurological Diseases: Insights from Preclinical Studies. Journal of clinical medicine, 5(12), 107. https://doi.org/10.3390/jcm5120107
  9. Day, G. (2023). State of care for autoimmune encephalitis and the extinguish trial of inebilizumab. Neurology live. https://www.neurologylive.com/view/state-care-autoimmune-encephalitis-extinguish-trial-inebilizumab
  10. The extinguish trial of inebilizumab in NMDAR encephalitis (extinguish). Yale Medicine. (2024). https://www.yalemedicine.org/clinical-trials/the-extinguish-trial-of-inebilizumab-in-nmdar-encephalitis-extinguish

Figures 1 and 2 made with biorender.com.

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Your generous Donations allow IAES to continue our important work and save lives!

 

 

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On June 16 th, 2022, Tabitha Orth, President and Founder of International Autoimmune Encephalitis Society officially became the 7,315 th “point of light”. Recognized for the volunteer work she and IAES has done to spark change and improve the world for those touched by Autoimmune Encephalitis. The award was founded by President George H.W. Bush in 1990.

 

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Become an Advocate by sharing your story. It may result in accurate diagnosis for someone suffering right now who is yet to be correctly identified. Submit your story with two photos to IAES@autoimmune-encephalitis.org  

 

 

International Autoimmune Encephalitis Society (IAES), home of the AEWarrior®, is the only Family/Patient-centered organization that assists members from getting a diagnosis through to recovery and the many challenges experienced in their journey. Your donations are greatly appreciated and are the direct result of IAES’ ability to develop the first product in the world to address the needs of patients, Autoimmune Encephalitis Trivia Playing Cards. Every dollar raised allows us to raise awareness and personally help Patients, Families, and Caregivers through their Journey with AE to ensure that the best outcomes can be reached. Your contribution to our mission will help save lives and improve the quality of life for those impacted by AE.   Trivia Playing cards 3 FB 500x419 - The Future of Anti-NMDAR Encephalitis Treatment: Exploring the ExTINGUISH Clinical Trial For this interested in face masks, clothing, mugs, and other merchandise, check out our AE Warrior Store!  This online shop was born out of the desire for the AE patient to express their personal pride in fighting such a traumatic disease and the natural desire to spread awareness. Join our AE family and help us continue our mission to support patients, families and caregivers while they walk this difficult journey.   AE Warrior Store 300x200 - The Future of Anti-NMDAR Encephalitis Treatment: Exploring the ExTINGUISH Clinical Trial

Be a part of the solution by supporting IAES with a donation today.

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A Mother’s Heartbreak

A Mother’s Heartbreak

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January 31, 2024 | by Laura Zendejas

Introduction from the IAES Blog Team:

A diagnosis of Autoimmune Encephalitis can be devastating and overwhelming. It is difficult for patients, family members, caregivers, and medical teams. Watching a loved one suffer can be excrutiating. Being a parent of a suffering child is a level of mental pain that no one ever wishes to encounter. We share with you a beautiful poem written by Laura Zendejas that speaks to the heartbreak a loving Mother feels for her sick child.

—-

NMDAR encephalitis

You took away my child

You took away my peace

You took away my feelings of blessings and feeling pleased

I was happy before you came

I was worry free

I knew my child was safe and healthy

Then you came to be

You attacked her brain

You attacked me

You made me realize I had no control

That you were the all mighty

I begged

I cried

I asked why

Still I have no answers

Still I search today

Now that you have left my child

Why do I still feel this way?

Why do I still feel you near?

You attacked her brain and you set her free….

So why are you still attacking me?

~a poem from mom

IMG 9622 - A Mother's Heartbreak

 

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Your generous Donations allow IAES to continue our important work and save lives!

 

 

Tabitha Orth 300x218 - A Mother's Heartbreak

 

 

On June 16 th, 2022, Tabitha Orth, President and Founder of International Autoimmune Encephalitis Society officially became the 7,315 th “point of light”. Recognized for the volunteer work she and IAES has done to spark change and improve the world for those touched by Autoimmune Encephalitis. The award was founded by President George H.W. Bush in 1990.

 

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Become an Advocate by sharing your story. It may result in accurate diagnosis for someone suffering right now who is yet to be correctly identified. Submit your story with two photos to IAES@autoimmune-encephalitis.org  

 

 

International Autoimmune Encephalitis Society (IAES), home of the AEWarrior®, is the only Family/Patient-centered organization that assists members from getting a diagnosis through to recovery and the many challenges experienced in their journey. Your donations are greatly appreciated and are the direct result of IAES’ ability to develop the first product in the world to address the needs of patients, Autoimmune Encephalitis Trivia Playing Cards. Every dollar raised allows us to raise awareness and personally help Patients, Families, and Caregivers through their Journey with AE to ensure that the best outcomes can be reached. Your contribution to our mission will help save lives and improve the quality of life for those impacted by AE.   Trivia Playing cards 3 FB 500x419 - A Mother's Heartbreak For this interested in face masks, clothing, mugs, and other merchandise, check out our AE Warrior Store!  This online shop was born out of the desire for the AE patient to express their personal pride in fighting such a traumatic disease and the natural desire to spread awareness. Join our AE family and help us continue our mission to support patients, families and caregivers while they walk this difficult journey.   AE Warrior Store 300x200 - A Mother's Heartbreak

Be a part of the solution by supporting IAES with a donation today.

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Psychosis or Something More? A Family’s Search for Answers

Psychosis or Something More? A Family’s Search for Answers

May 26, 2022 | By Libya Matney

Introduction from the IAES Blog Team:

The International Autoimmune Encephalitis Society is proud to present to you the AE story of one of our mighty Warriors in her own words, an article written about her AE path in the University of Arkansas newspaper (link below) and beautiful artwork given to her by a wonderful friend and artist depicting her within the struggle of this devastating diagnosis!

 

As a 21-year-old stay at home mom to a precious little boy, Benjamin, I never thought that something so life-altering would happen to me. My husband and I had spent 9 months trying to conceive our second child. Finally, in June of 2021, we were able to get pregnant. Around the same time, many random things started happening to my body. Nobody understood what was happening. My scalp was burning, I had chronic migraines, confusion, insomnia, OCD tendencies, and I started showing aggression towards my family. All these things seemed to begin to rule my life. I began cleaning my house aggressively and trying to get rid of everything that I own. I would tear things out of the closets and try to reorganize them at the same time. I was exhausted. I was forgetting everything. I began to believe that I couldn’t be left alone to take care of my son. My family and friends began taking turns staying with me during the day. At this point I had been to the doctor several times and had multiple blood tests and two CT scans. Everything came back normal.

On August 19th, 2021, my husband and mother-in-law decided to take me to a hospital in Fayetteville, Arkansas (AR) to see if they could figure out what was happening to me. They performed the same blood tests and scans that I had received previously and, of course, they came back normal. On the way home from the hospital that day, I had what the doctors would call a “psychotic break”. I began kicking and hitting my husband in the car and trying to open the door to get out. My husband and mother-in-law frantically called my mom. She said that she could hear my husband in the background begging me to stop. My mom told them that she was on her way to us and to call 911. When the police and Emergency Medical Services (EMS) arrived, my mom had my doctor on the phone to convince them that something was medically wrong with me and that I needed to be taken to the emergency room (ER). When EMS tried to get me to the gurney I dropped to the ground. They had to lift me onto the gurney and into the ambulance. This was when I was transported to the ER in my hometown, North Arkansas Regional Medical Center (NARMC). The last thing I remember from that fateful day was stopping in a restaurant parking lot and trying to get out of the car. I don’t remember the police or paramedics being there. I don’t remember anything from the rest of that day or the month that followed.

My family has told me that while I was in the ER, I kept trying to leave. I would fight the medical staff and my family so hard that they had to restrain my arms and legs to keep me from getting out of bed or hurting myself. During the 4 days that I was in the ER at NARMC, I had a CT scan, an MRI, a spinal tap, and multiple blood tests done. I ended up miscarrying my child the last day that I was there. I was transferred to St. Bernard’s Medical Center in Jonesboro, AR on August 23rd, 2021. During the transfer, I slipped into an unresponsive/catatonic state. A procedure was performed to remove the tissue from the fetus, as well as the same testing that had previously been done in the ER. Other testing that was done consisted of EEGs and ultrasounds. Six days after being transferred I was placed on a ventilator because of having back-to-back seizures and my heart stopping. After two weeks of having no nourishment besides IV fluids, a feeding tube was also placed in my nose. I was in St. Bernard’s for a month before they sent my blood and spinal fluid to Mayo Clinic. An infectious disease doctor diagnosed me with anti-NMDA Receptor Autoimmune Encephalitis and GFAP. A few days before I left St. Bernard’s, I woke up with a feeding tube still in my nose. I did not know the month, day, or what was happening. I couldn’t walk or use the right upper side of my body. Also, due to having been on the ventilator and having the feeding tube, I could not talk. I was given a letterboard to communicate and the first thing that I asked about was my pregnancy. I couldn’t remember miscarrying the baby. On September 22nd, I was transferred to Barnes Jewish Hospital in St. Louis, Mo. Doctors began plasmapheresis (plasma exchange).  During the 10 days that I was there I received 5 rounds of it. I had another MRI, EEG, spinal tap, and two ultrasounds during my stay there.  Blood and spinal fluid samples were sent to Mayo Clinic to be rechecked. On October 1st, I was moved to Everest Rehabilitation Center in Rogers, AR, where I spent every day in physical, occupational, and speech therapy. I had to relearn how to walk, and I had to regain my physical strength and my voice. My last week at the rehab center, I finally got to see my son, Benjamin, after not seeing him for over a month. They included him in my physical and occupational therapy. On October 19th, two months after being taken to the first hospital, I was released to finally go home. When I got home, I started outpatient physical therapy at Mount Carmel Physical Therapy Center in Harrison, AR. I had physical therapy twice a week for 8 weeks. In January of 2022, I had two rounds of Rituxan infusions.

I am now back home with husband and son, and I can enjoy spending time with my family and friends once again. My life will never be the same after my AE diagnosis. I will always have to keep tabs on my stress levels and watch for signs of relapse. I still have months before I can drive again and am still at risk for seizures. However, I have learned a lot the past year. I’ve been cared for by people that will forever hold a place in my heart. I’ve grown, I’ve changed, and I am thankful for the life and family that God has blessed me with. 

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subscribe - Psychosis or Something More? A Family's Search for Answers

Your generous Donations allow IAES to continue our important work and save lives! 

guidestar platinum logo 300x300 1 e1605914935941 - Psychosis or Something More? A Family's Search for Answers

 

 

 

 

Become an Advocate by sharing your story. It may result in accurate diagnosis for someone suffering right now who is yet to be correctly identified. Submit your story with two photos to IAES@autoimmune-encephalitis.org

 

 

International Autoimmune Encephalitis Society (IAES), home of the AEWarrior®, is the only Family/Patient-centered organization that assists members from getting a diagnosis through to recovery and the many challenges experienced in their journey. Your donations are greatly appreciated and are the direct result of IAES’ ability to develop the first product in the world to address the needs of patients, Autoimmune Encephalitis Trivia Playing Cards. Every dollar raised allows us to raise awareness and personally help Patients, Families, and Caregivers through their Journey with AE to ensure that the best outcomes can be reached. Your contribution to our mission will help save lives and improve the quality of life for those impacted by AE. 

Trivia Playing cards 3 FB 500x419 - Psychosis or Something More? A Family's Search for Answers

For those interested in face masks, clothing, mugs, and other merchandise, check out our AE Warrior Store!  This online shop was born out of the desire for the AE patient to express their personal pride in fighting such a traumatic disease and the natural desire to spread awareness. Join our AE family and help us continue our mission to support patients, families and caregivers while they walk this difficult journey.  

AE Warrior Store 300x200 - Psychosis or Something More? A Family's Search for Answers 

Be a part of the solution by supporting IAES with a donation today.

 

why zebra - Aphasia as a Symptom of Autoimmune Encephalitis

 

 

 

Our website is not a substitute for independent professional medical advice. Nothing contained on our website is intended to be used as medical advice. No content is intended to be used to diagnose, treat, cure or prevent any disease, nor should it be used for therapeutic purposes or as a substitute for your own health professional's advice. Although THE INTERNATIONAL AUTOIMMUNE ENCEPHALITIS SOCIETY  provides a great deal of information about AUTOIMMUNE ENCEPHALITIS, all content is provided for informational purposes only. The International Autoimmune Encephalitis Society  cannot provide medical advice.


International Autoimmune Encephalitis Society is a charitable non-profit 501(c)(3) organization founded in 2016 by Tabitha Andrews Orth, Gene Desotell and Anji Hogan-Fesler. Tax ID# 81-3752344. Donations raised directly supports research, patients, families and caregivers impacted by autoimmune encephalitis and to educating healthcare communities around the world. Financial statement will be made available upon request.

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