LEIDEN, Netherlands, August 13, 2026
Pharming Group N.V. announced the commercial launch of Joenja® (leniolisib) in Japan for adults and pediatric patients aged 4 years and older with activated phosphoinositide 3-kinase delta syndrome (APDS), following the product’s inclusion on Japan’s National Health Insurance (NHI) drug price list. The launch represents an important expansion of Pharming’s global rare-disease commercial footprint and makes Japan the first market worldwide where Joenja is commercially available for children aged 4 to 11 years. Joenja was approved by Japan’s Ministry of Health, Labour and Welfare (MHLW) in March 2026 as the first treatment specifically approved for APDS in the country. Under its agreement with Pharming, OrphanPacific, Inc. serves as the Marketing Authorization Holder in Japan and is responsible, in collaboration with Pharming, for product supply and distribution. The commercial launch provides a new treatment option for Japanese patients living with this rare primary immunodeficiency.
Joenja Targets the Underlying PI3Kδ Pathway
Joenja is an oral small-molecule PI3Kδ inhibitor designed to address the underlying immune dysregulation associated with APDS. APDS is caused by genetic variants affecting either the PIK3CD or PIK3R1 genes, which play important roles in immune-cell development and function. These genetic changes can result in excessive activity of the PI3Kδ pathway, disrupting normal immune-cell maturation and function. Patients may experience recurrent respiratory infections, lymphoproliferation, autoimmunity and enteropathy, while progressive disease can contribute to permanent organ damage and an increased risk of lymphoma. Leniolisib inhibits PI3Kδ signaling by reducing production of phosphatidylinositol-3-4-5-trisphosphate, an important cellular messenger involved in processes including immune-cell proliferation, differentiation, cytokine production and survival. The medicine has previously received approvals in several international markets for APDS, while Japan’s broader age indication extends commercial access to younger pediatric patients.
Japan Becomes Key Pediatric APDS Market
The Japanese approval and launch are particularly significant because APDS is an ultra-rare disease with substantial diagnostic challenges. Pharming estimates that APDS affects approximately 1 to 2 people per million worldwide, while patients can experience a median diagnostic delay of approximately seven years because symptoms overlap with other primary immunodeficiency disorders. Earlier and accurate diagnosis is important because APDS is progressive, and accumulated immune dysfunction can contribute to serious complications including lung damage and lymphoma. Genetic testing can provide a definitive diagnosis. By making Joenja commercially available to patients aged 4 years and older, Japan becomes an important market for earlier treatment intervention in pediatric APDS. The Japanese launch also expands the potential patient population eligible for Pharming’s approved therapy beyond the older pediatric and adult populations currently covered in several other markets. Leniolisib remains under regulatory review for pediatric APDS indications in additional countries.
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Pharming and OrphanPacific Advance Rare Disease Access
The commercialization of Joenja in Japan strengthens Pharming’s position in the global rare-disease market and demonstrates the importance of partnerships for bringing specialized medicines to local patient populations. OrphanPacific, a Japanese pharmaceutical company focused on rare and ultra-rare diseases, will support the product’s marketing authorization, supply and distribution activities in Japan under its agreement with Pharming. Joenja’s development is supported by clinical data from a randomized, placebo-controlled Phase III study, which demonstrated statistically significant improvements in its coprimary endpoints, while longer-term open-label data have provided additional information on safety and tolerability. Pharming continues to evaluate leniolisib in other potential applications, including Phase II studies involving primary immunodeficiencies with immune dysregulation. However, the safety and efficacy of leniolisib have not been established for these additional conditions. The Japanese launch therefore represents a commercial milestone for an already approved APDS therapy while the company continues expanding its rare-disease development pipeline.
Source:Pharming Group,,press release
