FDA Approves Pharming's Joenja as First Treatment for Children Aged 4 to 11 With APDS
核心洞察
The FDA approved Pharming's supplemental New Drug Application for 40 mg and 50 mg twice-daily leniolisib in children aged 4 to 11 weighing at least 27 kg with APDS.
Joenja becomes the first FDA-approved treatment for this younger pediatric APDS population, expanding an indication previously limited to patients 12 years and older.
Approval was supported by a multinational, open-label, single-arm Phase III study showing reduced lymphadenopathy and increased naive B cells over 12 weeks.
The U.S. Food and Drug Administration has approved Pharming's supplemental New Drug Application for 40 mg and 50 mg twice-daily dosing of Joenja (leniolisib) in children aged 4 to 11 years weighing at least 27 kg with activated phosphoinositide 3-kinase delta syndrome (搜索) (APDS), a rare primary immunodeficiency. The decision, announced September 11, 2026, makes Joenja the first FDA-approved treatment for this younger pediatric population in the United States.
Joenja is an oral, selective phosphoinositide 3-kinase delta (PI3Kδ) inhibitor. The newly approved doses are expected to be available to eligible pediatric patients in the U.S. in October through Pharming's established specialty distribution network and patient-support infrastructure.
Prior Approval and Regulatory Scope
Joenja received FDA approval in March 2023 for the treatment of APDS in adult and pediatric patients 12 years of age and older. The current indication covers adult and pediatric patients 4 years of age and older who weigh 27 kg or greater. The drug is also approved in the U.K., Australia, Israel, Canada and the European Union for patients 12 years and older, and in Japan for patients 4 years of age and older. Leniolisib remains under regulatory review for APDS in Canada and several other countries.
On July 30, Pharming submitted a separate supplemental New Drug Application seeking approval of lower Joenja doses for pediatric APDS patients aged 4 to 11 years who weigh 13 kg to less than 27 kg.
Phase III Data Supporting the Expansion
The approval is supported by data from a multinational, open-label, single-arm Phase III study in children aged 4 to 11 years with APDS. Over 12 weeks, treatment demonstrated improvements in two clinically relevant hallmarks of the condition: reduced lymphadenopathy and increased naive B cells, which together indicate an improvement in the underlying immune defect.
The safety profile was consistent with prior Joenja experience. All treatment-emergent adverse events were mild to moderate in nature, and no drug-related serious adverse events were observed.
In the broader safety information, seven (33%) patients 12 years and older (n=21) and five (63%) patients 4 to 12 years of age weighing 27 kg or greater (n=8) developed an absolute neutrophil count (ANC) between 500 and 1500 cells/microL after receiving Joenja. No patients developed an ANC below 500 cells/microL, and there were no reports of infection associated with neutropenia.
The most common adverse reactions (incidence >10%) in pediatric patients 4 to under 12 years of age weighing 27 kg or greater were abdominal pain, cough, and respiratory tract infection. In adult and pediatric patients 12 years and older, the most common adverse reactions were headache, sinusitis, atopic dermatitis, and weight gain.
Clinical Rationale for Earlier Intervention
APDS typically manifests in early childhood and is characterized by significant immune dysregulation and recurrent sinopulmonary infections, which over time can lead to permanent lung damage and other serious complications. The burden for children extends beyond clinical symptoms: recurrent infections, medical appointments and treatment demands may disrupt school attendance, learning and social development.
"To give children living with APDS the best chance at a healthier future, early disease intervention is critical," said Eveline Wu, M.D., MSCR, Associate Professor of Pediatrics at the University of North Carolina at Chapel Hill. "Previously, our best approach for children aged 4 to 11 years with APDS was to provide an accurate diagnosis and a treatment plan to manage the symptoms of APDS. With the approval of Joenja for this pediatric population, we can now take that support even further to address the underlying pathway of disease, with the goal of reducing symptoms and preventing the irreversible complications that often arise with APDS."
Vanessa Tenembaum, CEO of the Jeffrey Modell Foundation, an international non-profit organization dedicated to helping individuals and families affected by primary immunodeficiency disorders, framed the approval in terms of access to earlier treatment. "APDS is not a disease that waits. It can affect important aspects of childhood, potentially impacting time in school, time with friends, and other activities of daily life," she said. "This approval is a meaningful step forward because it gives younger patients and their physicians another much-needed option earlier in the disease journey."
Disease Biology and Diagnostic Burden
APDS was first characterized in 2013 and is caused by variants in either of two identified genes, PIK3CD (搜索) or PIK3R1 (搜索), which are vital to the development and function of immune cells. Variants of these genes lead to hyperactivity of the PI3Kδ pathway, causing immune cells to fail to mature and function properly, resulting in immunodeficiency and dysregulation.
The condition is characterized by severe, recurrent sinopulmonary infections, lymphoproliferation, autoimmunity, and enteropathy. Because these symptoms overlap with a variety of other conditions, including other primary immunodeficiencies, people with APDS are frequently misdiagnosed and experience a median 7-year diagnostic delay. As APDS is progressive, this delay may lead to an accumulation of damage over time, including permanent lung damage and lymphoma. A definitive diagnosis can be made through genetic testing. APDS affects approximately 1 to 2 people per million worldwide.
Mechanism and Broader Development Program
Joenja inhibits the production of phosphatidylinositol-3-4-5-trisphosphate, an important cellular messenger that regulates cell functions including proliferation, differentiation, cytokine production, cell survival, angiogenesis, and metabolism. Results from a randomized, placebo-controlled Phase III clinical trial previously 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 have supported the safety and tolerability of long-term leniolisib administration.
Leniolisib is also being evaluated in two Phase II clinical trials in primary immunodeficiencies (PIDs) with immune dysregulation, though the safety and efficacy of leniolisib have not been established for PIDs with immune dysregulation beyond APDS.
Safety Considerations and Access
Per the U.S. prescribing information, pregnancy status should be verified in females of reproductive potential before initiating Joenja. The drug may cause fetal harm when administered to a pregnant woman; patients should be advised of the potential risk to a fetus and to use highly effective contraception during treatment and for one week after the last dose. Women should not breastfeed during treatment and for one week after the last dose. Live, attenuated vaccinations may be less effective if administered during Joenja treatment. Joenja may cause hypersensitivity reactions, including anaphylaxis. Use in patients with moderate to severe hepatic impairment is not recommended, and there is no recommended dosage for patients under 4 years of age or weighing less than 27 kg. Co-administration with strong CYP3A4 inhibitors, strong or moderate CYP3A4 inducers, or BCRP, OATP1B1, and OATP1B3 substrates should be avoided. Joenja is available in 40 mg, 50 mg, and 70 mg tablets.
"Today's approval marks an important achievement in our efforts to expand the availability of Joenja to more individuals living with APDS," said Leverne Marsh, Chief Commercial Officer of Pharming. "Our immediate priority is to support physicians and families in navigating the access pathway so treatment can start as quickly and responsibly as possible."
Pharming Group N.V. is a global biotechnology company headquartered in Leiden, the Netherlands, with operations in the United States and Europe, focused on developing and commercializing medicines for rare immune and genetic diseases.