Last updated January 10, 2023, by Teresa Carvalho, MS
Fact-checked by Inês Martins, PhD
What is Exservan for ALS?
Exservan (riluzole oral film) is an oral treatment designed to slow the progression of amyotrophic lateral sclerosis (ALS). Its film formulation offers an alternative to riluzole tablets for patients who have trouble swallowing.
Exservan is sold as a film that dissolves on top of the tongue, but the active ingredient in it is also available in other formulations, including as a tablet called Rilutek. Generics also are available.
How does Exservan work?
ALS is a neurodegenerative disease characterized by the degeneration and death of motor neurons, the nerve cells that control voluntary muscle movements.
As these neurons are lost, muscles no longer receive signals that tell them to contract, leading to muscle weakness and atrophy. This results in severe disability including difficulty swallowing, which complicates the ingestion of oral tablets and suspensions.
Although Exservan’s exact mechanism of action is not fully understood, it’s thought to slow ALS progression by blocking glutamate signaling.
Glutamate is a neurotransmitter, or chemical messenger, released by nerve cells to transmit nerve signals. While necessary for nerve cell communication, excessive glutamate can result in nerve cell overactivation and contribute to their premature death.
In addition to preventing glutamate-induced nerve damage, Exservan also seems to reduce the accumulation of toxic TDP-43 proteins in nerve cells, a hallmark of the disease that’s observed in about 97% of ALS cases.
Who can use Exservan?
The U.S. Food and Drug Administration (FDA) approved Exservan in 2019 for treating ALS patients, providing an alternative riluzole therapy for those who have difficulty swallowing.
The therapy is not approved in outside the U.S. Under agreements with Aquestive, Zambon Pharma is responsible for the regulatory approval and marketing of Exservan in the European Union, and Haisco Pharmaceuticals is advancing the therapy in China.
Who should not use Exservan?
Exservan is not recommended for people with severe allergies to either riluzole or any other component in the medication. It also should not be used in patients with elevated levels of liver enzymes.
How is Exservan administered in ALS?
Exservan is available in orange rectangular-shaped films that contain 50 mg of the active medication. The dissolving films have a honey lemon flavor and are printed with “R50” in white on one side.
The recommended dose is 50 mg, taken as one oral film twice a day. The medication is placed on top of the tongue and completely dissolves in about two minutes with saliva, which may be swallowed normally.
Exservan should be taken at least an hour before and two hours after any meal, and must not be cut or split. Patients also are advised not to ingest any liquids and to refrain from chewing, spitting, or talking while the film dissolves.
Exservan in clinical trials
Exservan’s approval in the U.S. was supported by data from two clinical trials of Rilutek. In these trials, a tablet formulation of riluzole significantly extended the time to death or to require a tracheostomy – a tube inserted through the neck into the windpipe to help with breathing.
The approval package also included results from a study in healthy volunteers, called Study 162020, demonstrating that Exservan has an equivalent pharmacokinetics profile (how a drug is absorbed, distributed, and eliminated from the body) to Rilutek.
Study 162020 was a randomized clinical trial that tested a single dose of Exservan and Rilutek in 32 healthy volunteers. All participants received the two medications in fasting conditions and after a fatty meal, with one-week intervals between each study period.
Results showed the two formulations were generally equivalent, with similar amounts of riluzole reaching the blood, similar peak concentrations, and similar times to clearing half of the active ingredient from circulation. Also mimicking the effects of the tablet formulation, taking Exservan with food reduced the amount of riluzole absorbed by the body.
Common side effects of Exservan
The most common side effects of Exservan include:
- loss of sensation in the mouth
- lack of energy
- reduced lung function
- high blood pressure
- abdominal pain
Based on data from Rilutek clinical trials, riluzole may cause liver damage. It’s recommended that patients receiving Exservan or other riluzole-containing therapies are monitored for this potentially life-threatening side effect.
Patients should not take Exservan if levels of liver enzymes raise above five times the upper limit of normal and the therapy should be discontinued if there is evidence of liver dysfunction.
Low levels of white blood cells
Exservan can cause neutropenia, a condition wherein immune cells called neutrophils are lower than normal. It’s recommended that patients report any increases in body temperature to their healthcare team, as this condition is often accompanied by a fever.
Interstitial lung disease, a condition wherein lung tissue becomes scarred, can sometimes occur after treatment with Exservan. If this form of lung disease develops, treatment should be immediately stopped.
Use in pregnancy and breastfeeding
While there’s a lack well-designed studies investigating the use of Exservan in pregnant women, animal data suggests it may cause harm to a developing fetus. It’s also unknown if Exservan can pass to breast milk.
It’s recommended that women who are pregnant, breastfeeding, or planning to do so, talk with their healthcare provider to understand the potential risks of taking Exservan during these periods.
ALS News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.