The OraGrowtH Phase 3 Trial is a multi-national trial. The goals of the trial are to study LUM-201 as a treatment for Pediatric Growth Hormone Deficiency (PGHD) in naive to treatment children and validate the LUM-201 predictive enrichment marker (LUM-201 PEM) strategy to select subjects likely to respond to therapy with daily oral LUM-201.

Inclusion Criteria:

• Subjects must be naïve to treatment and prepubertal
• Subjects must have a maximal GH response of < 10 ng/mL from 2 prior GH stimulation tests conducted within the preceding 12 months
• Impaired height defined as ≥ 2.0 standard deviations (SDs) below the mean height for chronological age and sex
• Morning or random cortisol level of ≥ 7.0 μg/dL
• ≥ 3.0 years and age ≤ 10.0 years for girls and ≤ 11.0 years for boys
• Baseline height velocity (HV) based on ≥ 6 months of growth assessments < 25th percentile for age and sex
• Bone Age delay of ≥ 12 months compared to the chronological age
• In girls, have genetic testing results to rule out Turner syndrome. If SHOX genetic testing results are available, they need to be negative.
• Have normal thyroid function. Subjects diagnosed with hypothyroidism must have documented successful treatment for at least 3 months prior to Day 1
• Baseline IGF-1 standard deviation score (SDS) ≤ -1.0

Exclusion Criteria:

• Any medical or genetic condition which, in the opinion of the Investigator or Medical Monitor (MM), can be an independent cause of short stature and/or limit the response to exogenous growth factor treatment.
• Arm span to height ratio > 2 SDs below the mean for age and sex
• A medical or genetic condition that, in the opinion of the Investigator and/or MM, adds unwarranted risk to use of LUM-201
• Use of any medication that, in the opinion of the Investigator and/or MM, can independently cause short stature or limit the response to exogenous growth factors
• Current inflammatory diseases requiring systemic corticosteroid treatment for > 2 consecutive weeks within the last 3 months prior to the Screening Visit
• Use of hormone replacement therapy for any hormone deficiency other than thyroid deficiency
• Any ECG at the Screening Visit noted to have a clinically significant abnormality, as confirmed by the MM
• Any subjects suspected of having past or present intracranial tumor growth as confirmed by brain imaging prior to the Screening or Day 1 Visit
• Any subject suspected of having intracranial hypertension (IH) as confirmed by fundoscopy and other assessments
• Any subject with serum alanine transaminase (ALT), aspartate transaminase (AST), or total bilirubin > upper limit of normal (ULN)
• Suspicion of absent pituitary function as evidenced by a maximal stimulated GH ≤ 3.0 ng/mL on any prior standard of care GH stimulation test completed within 12 months
• Body weight ≤ 14.0 kg
• BMI < -2 or > +2 SDs for age and sex based on WHO standards
• Birth weight for gestational age < 3rd percentile based on WHO standards
• Treatment with medications known to be moderate or strong inhibitors or strong inducers of cytochrome P450 (CYP) 3A/4
• History of spinal, cranial, or total body irradiation
• Attention deficit hyperactivity disorder (ADHD) diagnosis