Pharming Group announces approval of Joenja® (leniolisib) in Japan for the treatment of APDS in patients aged 4 years and older

Rhea-AI Summary

Pharming (NASDAQ:PHAR / Euronext:PHARM) announced that Japan's MHLW approved Joenja (leniolisib) on March 24, 2026 for treatment of activated PI3K delta syndrome (APDS) in patients aged 4 years and older.

This is the first treatment approved in Japan for APDS and the first global approval for children aged 4–11; approval was based on positive Phase III data showing reduced lymphadenopathy and increased naïve B cells.

Positive

• First Japan approval for APDS
• First global approval for children aged 4–11 with APDS
• Phase III evidence showed significant reduction in lymphadenopathy and increased naïve B cells

Negative

• Common adverse reactions (>10%) include headache, sinusitis, and atopic dermatitis
• Commercial launch timing depends on National Health Insurance pricing agreement with MHLW

Market Context

This announcement highlights Japan’s approval of Joenja for APDS patients aged 4 years and older, in...

Analysis

This announcement highlights Japan’s approval of Joenja for APDS patients aged 4 years and older, including the first global approval for children 4 to 11. The decision followed Orphan Drug Designation in May 2023 and a Priority Review, supported by Phase III data showing improvements in lymphadenopathy and naïve B cells. Investors may focus on reimbursement discussions, timing of launch with OrphanPacific, and ongoing monitoring of adverse events occurring in more than 10% of patients.

Key Figures

Japan approval age range: 4 years and older Pediatric age range: 4 to 11 years Adult/adolescent study age: 12 years and older +5 more

8 metrics

Japan approval age range 4 years and older APDS patients eligible for Joenja treatment in Japan

Pediatric age range 4 to 11 years First global approval of Joenja for children with APDS

Adult/adolescent study age 12 years and older Global randomized Phase III leniolisib study population

Phase III duration 12 weeks Multinational pediatric Phase III study follow-up

Common adverse reactions >10% Incidence threshold for headache, sinusitis, atopic dermatitis

Orphan Drug date May 2023 MHLW Orphan Drug Designation for leniolisib in Japan

Priority Review Granted PMDA evaluation pathway for leniolisib application

Existing markets United States, United Kingdom Joenja approval for APDS patients ≥12 years

Key Terms

activated phosphoinositide 3-kinase delta (pi3kδ) syndrome, pi3k delta inhibitor, lymphadenopathy, naïve b cells, +4 more

8 terms

activated phosphoinositide 3-kinase delta (pi3kδ) syndrome medical

"First approved treatment in Japan for activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome"

Activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome is a rare genetic immune disorder in which a specific signaling protein (PI3Kδ) is abnormally active, causing recurring infections, immune system overreaction, and increased risk of lymph node and organ enlargement. Investors care because the condition creates a defined patient population and clear biological target for drugs or genetic therapies; clinical trial results, regulatory decisions, or new treatments can materially affect companies developing therapies and their market value.

pi3k delta inhibitor medical

"Joenja® (leniolisib), an oral, selective phosphoinositide 3-kinase (PI3K) delta inhibitor"

A PI3K delta inhibitor is a type of drug that blocks the PI3K delta enzyme, a cellular switch used by certain immune and blood cancer cells to grow and survive. Think of it as cutting power to a faulty circuit that fuels disease. For investors, these drugs matter because clinical trial success, safety profiles, and regulatory approval determine their commercial potential in treating blood cancers and immune disorders, affecting revenue and risk.

lymphadenopathy medical

"leniolisib met its co-primary endpoints by significantly reducing lymphadenopathy"

Swollen or abnormal lymph nodes caused by infection, inflammation, immune reactions, or cancer; they are the body's drainage and surveillance hubs, like neighborhood security posts that enlarge when something is wrong. Investors care because lymphadenopathy reported in clinical trials or product safety data can signal an adverse effect, disease progression, or efficacy issue that may delay approvals, change market expectations, or affect a company’s valuation.

naïve b cells medical

"significantly increasing the percentage of naïve B cells out of total B cells"

Naïve B cells are immune cells that have not yet encountered a specific germ or vaccine; they act like an untrained toolkit ready to be taught to recognize and fight new threats. For investors, their number and responsiveness matter because they influence how well vaccines, antibody drugs, or immune-based therapies can generate protective antibodies and long-term immunity, affecting clinical trial outcomes and product durability.

placebo-controlled medical

"the global, randomized, placebo-controlled study in patients aged 12 years and older"

"Placebo-controlled" describes a testing method where one group receives the actual treatment or intervention, while another group receives a harmless, inactive version called a placebo. This approach helps determine whether the real treatment has genuine effects beyond psychological expectations. For investors, understanding this ensures confidence that reported benefits are real and not influenced by bias or false perceptions.

orphan drug designation regulatory

"following the Orphan Drug Designation granted by the MHLW in May 2023"

Orphan drug designation is a special status given to medicines developed to treat rare diseases affecting only a small number of people. This status often provides benefits like faster approval processes and financial incentives, making it more attractive for companies to develop these drugs. For investors, it signals potential for exclusive market rights and reduced competition, which can impact the drug’s profitability.

priority review regulatory

"PMDA evaluated the application under the Priority Review pathway"

Priority review is a regulatory fast-track that shortens the time an agency spends evaluating a drug, vaccine or medical device application so a decision comes sooner than normal. For investors, it matters because a faster review is like an express lane to market: it can speed revenue potential and reduce regulatory uncertainty, but it does not guarantee approval and still requires the product to meet safety and effectiveness standards.

primary immunodeficiency medical

"targeted treatment option for this rare primary immunodeficiency in Japan"

A group of inherited disorders in which parts of the immune system are missing or don’t work properly, leaving people unusually prone to infections, autoimmune complications, or certain cancers. Investors watch these conditions because they create steady, long‑term demand for diagnostics and specialized treatments (including replacement therapies and gene therapies); successful clinical trials or approvals can rapidly change a company’s revenue outlook and valuation, similar to discovering a cure for a chronic condition that many patients need.

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• First approved treatment in Japan for activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome (APDS)
• Approval is based on positive Phase III data from multinational and Japanese studies in patients aged 12 years and older and a multinational pediatric study in children aged 4 to 11 years
• First approval of Joenja covering children aged 4 to 11 with APDS
  
  

Leiden, the Netherlands, March 24, 2026: Pharming Group N.V. (“Pharming” or “the Company”) (EURONEXT Amsterdam: PHARM/Nasdaq: PHAR) today announced that Japan’s Ministry of Health, Labour and Welfare (MHLW) has approved Joenja® (leniolisib), an oral, selective phosphoinositide 3-kinase (PI3K) delta inhibitor, for the treatment of activated PI3K delta syndrome (APDS) in adult and pediatric patients aged 4 years and older.

With this approval, Joenja becomes the first treatment approved in Japan specifically for APDS and the first approved treatment anywhere globally, for children aged 4 to 11 with the disease. Under an agreement with Pharming, OrphanPacific, Inc. serves as the Marketing Authorization Holder for Joenja in Japan and in collaboration with Pharming, is responsible for supply and distribution of the product. The launch of Joenja is expected following agreement with the MHLW on its National Health Insurance drug price.

Professor Hirokazu Kanegane, MD, PhD, Department of Child Health and Development at the Graduate School of Medical and Dental Sciences, Institute of Science Tokyo commented:
“Patients with APDS in Japan have until now relied largely on supportive care, so this approval marks an important step forward for the APDS community. This approval introduces the first approved targeted treatment option for this rare primary immunodeficiency in Japan, and has the potential to help reduce the burden of disease for patients and their families.”

Leverne Marsh, Chief Commercial Officer of Pharming, commented:
“The approval of Joenja for patients as young as 4 years of age is an important milestone for the APDS community in Japan. As the first treatment approved specifically for APDS in the country, it is the only targeted treatment option for patients and families affected by this rare and progressive disease. It also marks the first approval globally for children aged 4 to 11 with APDS. Together with OrphanPacific, we look forward to working through the next steps to help make Joenja available to patients in Japan as quickly as possible.”

The MHLW based the approval on data from Pharming’s Phase III clinical program for leniolisib in APDS, including the global, randomized, placebo-controlled study in patients aged 12 years and older, in which leniolisib met its co-primary endpoints by significantly reducing lymphadenopathy and significantly increasing the percentage of naïve B cells out of total B cells. This reflects a clinically relevant impact on immune dysregulation and deficiency which are hallmarks of APDS. Leniolisib was generally well tolerated with the most common adverse reactions (>10%) being headache, sinusitis, and atopic dermatitis. Supporting Phase III evidence also included the open-label Japanese study in patients aged 12 years and older, as well as positive data from the open-label, multinational Phase III study in children aged 4 to 11 years, including sites in Japan, which showed improvements over 12 weeks in reduced lymphadenopathy and increased percentage of naïve B cells from total B cells.

The Japanese Pharmaceuticals and Medical Devices Agency (PMDA) evaluated the application under the Priority Review pathway following the Orphan Drug Designation granted by the MHLW in May 2023.

Joenja® is approved and marketed in the United States and the United Kingdom for patients 12 years of age and older with APDS.

About Activated Phosphoinositide 3-Kinase δ Syndrome (APDS) 
APDS is a rare primary immunodeficiency that was first characterized in 2013. APDS is caused by variants in either one of two identified genes known as PIK3CD or PIK3R1, which are vital to the development and function of immune cells in the body. Variants of these genes lead to hyperactivity of the PI3Kδ (phosphoinositide 3-kinase delta) pathway, which causes immune cells to fail to mature and function properly, leading to immunodeficiency and dysregulation^1,2,3 APDS is characterized by a variety of symptoms, including severe, recurrent sinopulmonary infections, lymphoproliferation, autoimmunity, and enteropathy.^4,5 Because these symptoms can be associated with a variety of conditions, including other primary immunodeficiencies, it has been reported that people with APDS are frequently misdiagnosed and suffer a median 7-year diagnostic delay.⁶ As APDS is a progressive disease, this delay may lead to an accumulation of damage over time, including permanent lung damage and lymphoma.^4-7 A definitive diagnosis can be made through genetic testing. APDS affects approximately 1 to 2 people per million worldwide.⁸

About Joenja® (leniolisib)
Leniolisib is an oral small molecule phosphoinositide 3-kinase delta (PI3Kẟ) inhibitor approved as the first and only targeted treatment of activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome (APDS) in the U.S., U.K., Australia and Israel in adult and pediatric patients 12 years of age and older and in Japan for patients 4 years of age and older. Leniolisib inhibits the production of phosphatidylinositol-3-4-5-trisphosphate, which serves as an important cellular messenger and regulates a multitude of cell functions such as proliferation, differentiation, cytokine production, cell survival, angiogenesis, and metabolism. Results from a randomized, placebo-controlled Phase III clinical trial demonstrated statistically significant improvement in the coprimary endpoints, reflecting a favorable impact on the immune dysregulation and deficiency seen in these patients, and open label extension data has supported the safety and tolerability of long-term leniolisib administration.^9,10

Leniolisib is currently under regulatory review for the treatment of APDS in the European Economic Area, Canada and several other countries. Leniolisib is also being evaluated in two Phase II clinical trials in primary immunodeficiencies (PIDs) with immune dysregulation. The safety and efficacy of leniolisib has not been established for PIDs with immune dysregulation beyond APDS.

About Pharming Group N.V.
Pharming Group N.V. (EURONEXT Amsterdam: PHARM/Nasdaq: PHAR) is a global biopharmaceutical company dedicated to transforming the lives of patients with rare, debilitating, and life-threatening diseases. We are developing and commercializing a portfolio of innovative medicines, including small molecules and biologics. Pharming is headquartered in Leiden, the Netherlands, with a significant proportion of its employees based in the U.S.

For more information, visit www.pharming.com and find us on LinkedIn.
  
Forward-looking Statements
This press release may contain forward-looking statements. Forward-looking statements are statements of future expectations that are based on management’s current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance, or events to differ materially from those expressed or implied in these statements. These forward-looking statements are identified by their use of terms and phrases such as “aim”, “ambition”, ‘‘anticipate’’, ‘‘believe’’, ‘‘could’’, ‘‘estimate’’, ‘‘expect’’, ‘‘goals’’, ‘‘intend’’, ‘‘may’’, “milestones”, ‘‘objectives’’, ‘‘outlook’’, ‘‘plan’’, ‘‘probably’’, ‘‘project’’, ‘‘risks’’, “schedule”, ‘‘seek’’, ‘‘should’’, ‘‘target’’, ‘‘will’’ and similar terms and phrases. Examples of forward-looking statements may include statements with respect to timing and progress of Pharming's preclinical studies and clinical trials of its product candidates, Pharming's clinical and commercial prospects, and Pharming's expectations regarding its projected working capital requirements and cash resources, which statements are subject to a number of risks, uncertainties and assumptions, including, but not limited to the scope, progress and expansion of Pharming's clinical trials and ramifications for the cost thereof; and clinical, scientific, regulatory, commercial, competitive and technical developments. In light of these risks and uncertainties, and other risks and uncertainties that are described in Pharming's 2024 Annual Report and the Annual Report on Form 20-F for the year ended December 31, 2024, filed with the U.S. Securities and Exchange Commission, the events and circumstances discussed in such forward-looking statements may not occur, and Pharming's actual results could differ materially and adversely from those anticipated or implied thereby. All forward-looking statements contained in this press release are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. Readers should not place undue reliance on forward-looking statements. Any forward-looking statements speak only as of the date of this press release and are based on information available to Pharming as of the date of this release. Pharming does not undertake any obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information.

Inside Information
This press release relates to the disclosure of information that qualifies, or may have qualified, as inside information within the meaning of Article 7(1) of the EU Market Abuse Regulation.

References 

1. Lucas CL, et al. Nat Immunol. 2014;15(1):88-97.
2. Elkaim E, et al. J Allergy Clin Immunol. 2016;138(1):210-218.
3. Nunes-Santos C, Uzel G, Rosenzweig SD. J Allergy Clin Immunol. 2019;143(5):1676-1687.
4. Coulter TI, et al. J Allergy Clin Immunol. 2017;139(2):597-606.
5. Maccari ME, et al. Front Immunol. 2018;9:543.
6. Jamee M, et al. Clin Rev Allergy Immunol. 2020 Dec;59(3):323-333.
7. Condliffe AM, Chandra A. Front Immunol. 2018;9:338.
8. Vanselow S, et al. Frontiers in Immunology. 2023;14:1208567.
9. Rao VK, et al Blood. 2023 Mar 2;141(9):971-983.
10. Rao VK, et al. J Allergy Clin Immunol 2024;153:265-74.

For further public information, contact:
Investor Relations
Michael Levitan, VP Investor Relations & Corporate Communications
T: +1 (908) 705 1696
E: investor@pharming.com

Media Relations
Global: Saskia Mehring, Corporate Communications Manager
T: +31 6 28 32 60 41
E: media.relations@pharming.com

U.S.: Ethan Metelenis (Precision AQ on behalf of Pharming)
T: +1 (917) 882-9038

Netherlands: Leon Melens (LifeSpring Life Sciences Communication on behalf of Pharming)
T: +31 6 53 81 64 27

Attachment

• FINAL_Pharming Group announces approval of Joenja® in Japan_EN_24Mar2026

FAQ

What did Pharming announce on March 24, 2026 regarding Joenja (PHARM)?

Pharming announced MHLW approval of Joenja for APDS in patients aged 4 years and older. According to the company, approval is based on Phase III data showing reduced lymphadenopathy and increased percentage of naïve B cells.

Does the Japan approval for Joenja cover pediatric patients under 12 (PHARM)?

Yes. Joenja is approved in Japan for children aged 4 to 11 years, the company’s first global approval for that age group. According to the company, pediatric Phase III data showed improvements over 12 weeks.

What clinical evidence supported the MHLW approval of Joenja (PHARM)?

Approval was supported by Phase III studies showing significant reduction in lymphadenopathy and increased naïve B cells. According to the company, evidence included global, Japanese, and pediatric Phase III data.

When will Joenja (PHARM) be available in Japan after the March 24, 2026 approval?

Availability follows agreement with MHLW on National Health Insurance drug pricing, which must be finalized before launch. According to the company, OrphanPacific will handle marketing authorization, supply, and distribution.

What are the most common side effects of Joenja reported in the approval (PHARM)?

The most common adverse reactions (>10%) were headache, sinusitis, and atopic dermatitis. According to the company, leniolisib was generally well tolerated across studied populations.

Who will commercialize Joenja in Japan after the March 24, 2026 approval (PHARM)?

Under the agreement, OrphanPacific serves as the Marketing Authorization Holder and will collaborate with Pharming on supply and distribution in Japan. According to the company, OrphanPacific will lead commercialization activities.