New Analysis Demonstrates Impaired Work Productivity and Increased Unemployment Rates in Adults with X-linked Hypophosphatemia (XLH)

Findings from XLH Disease Monitoring Program (DMP) published in Journal of Bone and Mineral Research (JBMR Plus)

DMP is a global effort, supported by Kyowa Kirin, to advance understanding and care of XLH through real-world research

Additional findings at American Society for Bone and Mineral Research annual meeting in Toronto, Sept 27-30

PRINCETON, N.J., Sept. 10, 2024 /PRNewswire/ -- Kyowa Kirin, Inc., an affiliate of Kyowa Kirin Co., Ltd. (Kyowa Kirin, TSE: 4151), today announced the publication of a new analysis showing low levels of full-time employment and impaired work productivity among working age adults enrolled in the XLH Disease Monitoring Program, a prospective, 10-year, observational study of adults and children with X-linked hypophosphatemia in the US, Canada, and Latin America.

X-linked hypophosphatemia is a rare, genetic, progressive, phosphate-wasting disorder that can cause skeletal abnormalities, stiffness, pain, and impaired physical function.[1] This analysis of baseline data from the XLH DMP (N=281) showed that 31% of working age adults with XLH were not employed—a rate eight times higher than in the US general population and five times higher than in the EU— and 15% were receiving disability payments.[2],[3]

Additionally, individuals with a higher number of past orthopedic surgeries, and those with worse physical function, were less likely to be employed. Among those employed (n=193), the majority (60%) were working in light or sedentary roles and those in heavier work roles reported worse pain on average.

"These findings highlight the substantial burden of XLH, which impacts multiple aspects of affected individuals' lives. Exploring real-world experiences helps to expand understanding of the disease beyond clinical endpoints to outcomes that are meaningful to patients," said lead author, Professor Aliya Khan MD, McMaster University, Canada. "Here, we learn that adults with XLH experienced challenges in the workplace. Understanding the factors underpinning this is an important consideration when planning patient care."

A disease monitoring program provides an alternative to a traditional registry and extensive post-marketing studies and uses a collaborative, multi-stakeholder approach to monitor disease manifestations over an extended period, without limiting participants based on treatment received. 

"Kyowa Kirin is committed to generating real-world evidence that builds greater understanding of the XLH patient experience and the effectiveness of treatment on outcomes relevant to patients and clinicians, in both the short and long term," said Ben Johnson, study author and director of global health economics and outcomes research at Kyowa Kirin. "We look forward to sharing further findings from the XLH DMP and other real-world studies at the American Society for Bone and Mineral Research annual meeting in September."

This study was designed to investigate the association of patient characteristics and work productivity; causality was not assessed and should not be inferred based on these findings. The study population was predominantly from the US (80.8%, with the remaining 19.2% from Brazil, Canada, and Chile), which may have different employment profiles, limiting the generalizability of the results outside the US.

About the XLH Disease Monitoring Program

The XLH DMP is an international, prospective, 10-year, longitudinal, observational study of adults and children with XLH (NCT03651505) designed to characterize XLH disease presentation and progression, and prospectively assess changes over time in biochemical, clinical, and patient/caregiver-reported outcomes in a representative population. The DMP steering committee includes clinical experts in XLH, patient advocates from the XLH Network, and representatives from Kyowa Kirin and Ultragenyx Pharmaceutical.

About X-linked hypophosphatemia

X-linked hypophosphatemia is a rare, lifelong, genetic disease that can impact the bones and muscles in both children and adults. In individuals with XLH, the body doesn't hold on to enough phosphorus, which is an essential mineral for bone health. This is due to the production of excess fibroblast growth factor 23 (FGF23), causing the body to release too much phosphorus through the urine. When phosphorus levels are too low (hypophosphatemia), it can cause the softening and weakening of growing bones in children (rickets) and of mature bones in adults (osteomalacia). In children, XLH typically appears as bowed legs or knock knees. Over time, bone weakening can also lead to bone abnormalities in the legs, delayed growth, and short stature. In adults, XLH may cause osteomalacia, fractures and pseudo-fractures, and hypophosphatemia.

About Kyowa Kirin

Kyowa Kirin aims to discover novel medicines with life-changing value. As a Japan-based Global Specialty Pharmaceutical Company, we have invested in drug discovery and biotechnology innovation for more than 70 years and are currently working to engineer the next generation of antibodies and cell and gene therapies with the potential to help patients affected by severe and rare diseases. A shared commitment to our values, to sustainable growth, and to making people smile unites us across our four regions—Japan, Asia Pacific, North America, and EMEA/International. Learn more at: kkna.kyowakirin.com or LinkedIn: Kyowa Kirin Inc. U.S.

References

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¹ Beck-Nielsen S.S. et al. FGF23 and its role in X-linked hypophosphatemia-related morbidity. Orphanet J Rare Dis. 2019

² US Bureau of Labor Statistics. Labor Force Statistics from the Current Population Survey.

³ Unemployment rates, Euro Area Unemployment Rate. June 2024.

SOURCE Kyowa Kirin