• Diagnosed with a deficiency or absence of endogenous testosterone due to primary or secondary hypogonadism of a known etiology. Children with combined hormone deficiencies are permitted to enroll (but the child must already be receiving treatment for concomitant hormonal deficiencies)

• Participants receiving prior testosterone treatment must be receiving a stable dose for at least 12 weeks prior to Screening

• Have parent(s) or a legal guardian who will voluntarily provide written informed consent for the child to participate in the study

• Willing to provide assent for participation in the study

• Be a male 12 to \< 18 years of age at the time of consent/assent

• Have Legally Authorized Representative who is able to understand and comply with all study procedures and agrees to have the child participate in the study program as outlined in the protocol

• Requires chronic pharmacologic support for the initiation and/or continuation of pubertal maturation

• Have a body mass index (BMI)-for-age greater than the 5th percentile and weigh ≥ 40 kg

• If sexually active with a female partner of child-bearing potential, agrees to:

‣ Practice true abstinence including 30 days after the last IP administration, or,

⁃ Use 2 adequate forms of highly effective contraception, one of which should be a physical barrier, during the study and for 30 days after the last IP administration.