Xeris Receives USPTO Notice of Allowance for New Patent Covering KEVEYIS®, Extending Potential Protection Through 2039
Xeris Pharmaceuticals, Inc., a wholly owned subsidiary of Biopharma Holdings, Inc., has announced a significant intellectual property milestone for KEVEYIS® (dichlorphenamide), its FDA-approved treatment for primary periodic paralysis (PPP). The company revealed that the United States Patent and Trademark Office (USPTO) has issued a Notice of Allowance related to U.S. Patent Application No. 17/151,405, entitled “Compositions and Methods of Use.”
The development represents an important step in strengthening the company’s intellectual property portfolio surrounding KEVEYIS, a therapy used to treat a rare and debilitating neuromuscular disorder. Once the patent is formally issued and listed with the U.S. Food and Drug Administration (FDA), Xeris expects the patent to provide protection for KEVEYIS through 2039, assuming all required maintenance fees are paid and regulatory procedures are completed.
The announcement underscores the company’s ongoing commitment to supporting patients affected by primary periodic paralysis, a rare genetic disease for which treatment options remain limited.
Patent Allowance Marks Important Regulatory Milestone
A Notice of Allowance is issued by the USPTO when patent examiners determine that a patent application satisfies the legal requirements for patentability. While the notice does not itself constitute a granted patent, it signals that the examination process has been successfully completed and that the patent is expected to be issued following the completion of standard administrative procedures.
The newly allowed claims relate specifically to the use of KEVEYIS and provide additional intellectual property protection for the product.
Following formal issuance of the patent, Xeris plans to submit it to the FDA for inclusion in the agency’s publication Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. The Orange Book serves as the official reference for approved drug products and associated patent protections in the United States.
Listing a patent in the Orange Book can provide important commercial and regulatory benefits, helping protect innovative therapies while providing transparency regarding patent coverage and exclusivity periods.
According to the company, the newly issued patent is expected to extend protection for KEVEYIS until 2039, potentially strengthening the product’s long-term commercial position within the rare disease market.
Commitment to an Underserved Patient Community
Commenting on the announcement, Xeris Chief Executive Officer John Shannon emphasized the importance of KEVEYIS for patients living with primary periodic paralysis and highlighted the company’s dedication to supporting this rare disease community.
Shannon noted that KEVEYIS remains the first and only FDA-approved therapy specifically indicated for primary periodic paralysis. He stated that the Notice of Allowance reflects the company’s long-standing commitment to ensuring continued access to treatment for patients who depend on the medication.
According to Shannon, strengthening the intellectual property surrounding KEVEYIS helps support the company’s ability to continue providing not only the therapy itself but also the broader resources and patient support programs associated with treatment.
The executive emphasized that the company’s mission extends beyond commercial success, focusing on improving outcomes and quality of life for individuals living with rare and often overlooked medical conditions.
Understanding Primary Periodic Paralysis
Primary periodic paralysis is a rare inherited neuromuscular disorder characterized by episodes of muscle weakness, loss of muscle function, and temporary paralysis.
The condition results from genetic mutations that affect ion channels responsible for regulating muscle activity. These mutations disrupt the normal movement of electrolytes such as potassium across cell membranes, leading to periodic episodes of muscle dysfunction.
The disease can vary significantly in severity from one patient to another. Some individuals experience infrequent episodes of weakness, while others may suffer recurrent attacks that interfere with daily activities, employment, education, and overall quality of life.
Over time, many patients may also develop progressive muscle weakness that persists even between attacks.
PPP is generally classified into several subtypes, including:
- Primary hyperkalemic periodic paralysis
- Primary hypokalemic periodic paralysis
- Related genetic variants associated with periodic paralysis
Because the disease is rare, patients often face significant challenges obtaining an accurate diagnosis and accessing specialized treatment.
KEVEYIS: The First FDA-Approved Treatment for PPP
KEVEYIS (dichlorphenamide) represents an important advancement in the treatment of primary periodic paralysis.
The medication is approved by the FDA for the treatment of primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and related variants of the disorder.
Clinical studies have demonstrated that KEVEYIS can reduce the frequency, severity, and duration of paralysis attacks experienced by patients with PPP. By helping control these episodes, the therapy may enable patients to maintain greater independence and improve daily functioning.
The approval of KEVEYIS marked a significant milestone for the rare disease community, providing a dedicated treatment option for a condition that historically had limited therapeutic choices.
For many patients, the availability of an approved therapy has represented an important step toward more consistent disease management and symptom control.
Importance of Intellectual Property Protection
In the biopharmaceutical industry, intellectual property protection plays a critical role in supporting continued investment in research, development, and patient support initiatives.
The development of treatments for rare diseases often requires substantial financial investment despite relatively small patient populations. Patent protection helps provide companies with the opportunity to recover development costs and continue investing in innovation.
For therapies such as KEVEYIS, intellectual property rights can also help ensure manufacturing consistency, long-term product availability, and ongoing support programs designed for patients and healthcare providers.
The newly allowed patent further strengthens Xeris’ position as the company continues to focus on rare disease treatment and commercialization efforts.
Safety Considerations and Important Prescribing Information
As with any prescription medication, KEVEYIS carries important safety information and precautions that healthcare providers must consider when prescribing the therapy.
Contraindications
KEVEYIS should not be used in patients with known hypersensitivity to dichlorphenamide or other sulfonamide-containing medications.
The drug is also contraindicated in patients receiving high-dose aspirin therapy due to the increased risk of serious adverse reactions.
Additionally, use is contraindicated in individuals with severe pulmonary disease that may impair compensation for metabolic acidosis, as well as in patients with hepatic insufficiency, where the therapy may worsen hepatic encephalopathy.
Hypersensitivity and Serious Reactions
Because dichlorphenamide is a sulfonamide derivative, patients may be at risk for severe hypersensitivity reactions.
Serious reactions associated with sulfonamides can include:
- Stevens-Johnson syndrome
- Toxic epidermal necrolysis
- Fulminant hepatic necrosis
- Agranulocytosis
- Aplastic anemia
- Other severe blood disorders
Healthcare providers are advised to discontinue treatment immediately if signs of skin rash or other potentially life-threatening immune-mediated reactions occur.
Risk of Metabolic Acidosis
KEVEYIS belongs to a class of medications known as carbonic anhydrase inhibitors, which can cause hyperchloremic non-anion gap metabolic acidosis.
The risk may increase when the medication is used alongside other drugs capable of causing metabolic acidosis.
Patients receiving treatment should undergo baseline and periodic monitoring of serum bicarbonate levels to detect potential abnormalities early.
If metabolic acidosis develops or persists, dose adjustments or discontinuation may be necessary.
Hypokalemia Monitoring
The medication increases potassium excretion and may lead to hypokalemia, a condition characterized by abnormally low potassium levels.
Certain patient populations may be at higher risk, including those with conditions associated with potassium loss and those receiving medications such as:
- Loop diuretics
- Thiazide diuretics
- Laxatives
- Certain antifungal medications
- Penicillin-based therapies
- Theophylline
Regular monitoring of serum potassium levels is recommended throughout treatment.
Fall Risk
Clinical experience has shown that KEVEYIS may increase the likelihood of falls, particularly among elderly patients and those receiving higher doses.
Healthcare providers may consider dose reduction or discontinuation if fall-related complications occur during treatment.
Pregnancy and Breastfeeding Considerations
The use of KEVEYIS during pregnancy should be carefully evaluated, with treatment recommended only when potential benefits outweigh potential risks to the developing fetus.
It remains unknown whether dichlorphenamide is excreted in human breast milk. Therefore, caution should be exercised when administering the medication to nursing mothers.
Common Adverse Reactions
The most frequently reported adverse reactions observed during clinical studies included:
- Paresthesia (tingling or numbness sensations)
- Cognitive disturbances
- Dysgeusia (altered taste perception)
- Confusional states
While these side effects were among the most commonly reported, healthcare providers are encouraged to review the full prescribing information to ensure comprehensive understanding of the therapy’s safety profile.
Strengthening the Future of Rare Disease Care
The USPTO’s Notice of Allowance represents more than a legal or commercial milestone for Xeris. It reflects the company’s ongoing commitment to supporting patients affected by primary periodic paralysis, a condition that has historically received limited attention due to its rarity.
With the anticipated issuance of the patent and its planned listing in the FDA Orange Book, KEVEYIS is expected to gain additional intellectual property protection extending through 2039. This development may help secure the long-term availability of the therapy while supporting continued investment in patient services, education, and rare disease research.
As Xeris continues to expand its portfolio of innovative therapies, the company remains focused on its mission of improving the lives of patients living with serious and underserved medical conditions. The strengthening of KEVEYIS’ patent estate represents an important step toward achieving that goal and ensuring that individuals affected by primary periodic paralysis continue to have access to a dedicated treatment option for years to come.
About Xeris
Xeris (Nasdaq: XERS) is a fast-growing biopharmaceutical company committed to improving patient lives by developing and commercializing innovative products across a range of therapies. Xeris has three commercially available products: RECORLEV®, for the treatment of endogenous Cushing’s syndrome; GVOKE®, a ready-to-use liquid glucagon for the treatment of severe hypoglycemia; and KEVEYIS®, a proven therapy for primary periodic paralysis.
Xeris also has a pipeline of development programs led by XP-8121, a Phase 3-ready, once-weekly subcutaneous injection for hypothyroidism, as well as multiple early-stage programs leveraging Xeris’ technology platforms, XeriSol® and XeriJect®, for its partners.
