WHAT IS PEDIATRIC GROWTH HORMONE DEFICIENCY (PGHD)?
Growth hormone (GH) deficiency is the consequence of inadequate secretion of growth hormone from the pituitary gland. This results in low GH in the body, insufficient production of downstream signaling molecules required for growth and the subsequent lack of growth. In children, this rare disorder is called pediatric growth hormone deficiency (PGHD).
Secretion of GH is under strict hormonal feedback control. Growth hormone-releasing hormone (GHRH) and ghrelin are stimulators of its production while somatostatin produces a strong inhibitory action.
GH is the most important hormone regulating growth in childhood and adolescence.
CAUSES OF PGHD
PGHD can be congenital (children are born with the condition), acquired (brain tumor, head injuries or other causes), iatrogenic (induced by treatment for cancer), or idiopathic (of unknown cause), and ranges from severe to moderate.
We believe LUM-201 has the potential to improve the lives of patients with PGHD
In children, PGHD results in and manifests as slower than normal growth. Children are usually diagnosed by approximately seven years of age due to short stature and stunted growth velocity, although some children are not diagnosed until delay in pubertal growth spurt. About 1 in 3500 children are diagnosed with PGHD.3
PGHD is generally diagnosed by clinical observations and multiple tests, including radiographic assessment of bone age and tests of other hormones.
GH release stimulation tests are often needed to confirm PGHD diagnosis.
Current treatment options are limited to daily injectable formulations of recombinant human growth hormone (rhGH). Treatment should be started as soon as PGHD diagnosis is confirmed. Long-term (seven years or longer) treatment is not uncommon to achieve “catch-up” growth and reach full height potential. Unfortunately, daily injections can be painful, potentially leading to missed doses and sub-optimal growth.1,2
Treatment response is assessed by measurement of height and growth velocity. Treatment is usually continued until final height, completion of skeletal bone maturation (epiphyseal closure), or both have been recorded.
The main therapeutic goal of growth hormone treatment in children with PGHD is to enable these children to achieve normal height, with accompanying improvement of the psychosocial problems related to short stature.
LUM-201, also known as ibutamoren, is an orally administered small molecule that promotes the secretion of GH from the pituitary gland.
LUM-201 has been observed to increase the amplitude of endogenous pulsatile GH secretion, which mimics the natural pattern of GH secretion.
LUM-201 has been studied in more than 1200 patients (approximately 150 children) and was generally well-tolerated.
Pediatric Growth Hormone Deficiency has a number of different causes; not all patients will benefit from treatment with LUM-201. Predictive enrichment markers (PEMs) that test for pituitary function should enable clinicians to determine which patients may benefit from LUM-201.
- Have a functional but reduced hypothalamic pituitary growth hormone axis
- Expected to respond to LUM-201
- Represents 50-60% of PGHD patients
- Have a non-functional hypothalamic pituitary growth hormone axis
- Not expected to respond to LUM-201
- Represents 40-50% of PGHD patients
Lumos Pharma intends to develop LUM-201 as an orally administered product to treat children with pediatric growth hormone deficiency (PGHD). Recombinant human GH is approved for use in many other rare indications beyond PGHD including Turner syndrome, Children Born Small for Gestational Age, Prader-Willi Syndrome, Idiopathic Short Stature (ISS) and several others. Lumos Pharma plans to develop LUM-201 for treatment of several of these additional indications.
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GHD INFORMATIONAL SOURCES
Short Stature: Comparison of WHO and National Growth Standards/References for Height – Henrik Thybo Christesen, Birgitte Tønnes Pedersen, Effie Pournara, Isabelle Oliver Petit, Pétur Benedikt Júlíusson – PLOSone
Non-Compliance with Growth Hormone Treatment in Children Is Common and Impairs Linear Growth – Wayne S. Cutfield, Jose ́ G. B. Derraik, Alistair J. Gunn, Kyle Reid, Theresa Delany, Elizabeth Robinson, Paul L. Hofman – PLOS One
Growth Hormone Research Society Perspective on Biomarkers of GH Action in Children and Adults – Gudmundur Johannsson, Martin Bidlingmaier, Beverly M K Biller, Margaret Boguszewski, Felipe F Casanueva, Philippe Chanson, Peter E Clayton, Catherine S Choong, David Clemmons, Mehul Dattani, Jan Frystyk, Ken Ho, Andrew R Hoffman, Reiko Horikawa, Anders Juul, John J Kopchick, Xiaoping Luo, Sebastian Neggers, Irene Netchine, Daniel S Olsson, Sally Radovick, Ron Rosenfeld, Richard J Ross, Katharina Schilbach, Paulo Solberg, Christian Strasburger, Peter Trainer, Kevin C J Yuen, Kerstin Wickstrom, Jens O L Jorgensen, and the Growth Hormone Research Society
1. Rosenfeld, R. et al, Compliance and Persistence in Pediatric and Adult Patients Receiving Growth Hormone Therapy, Endocrine Practice, 2008, 14(2):143-154
2. Cutfield, W.S. et al, Non-Compliance with Growth Hormone Treatment in Children Is Common and Impairs Linear Growth, PLOS ONE, 2011, 6(1): e16223
3. Lindsay Journal of Pediatrics, 1994, 125(1):29-35