Testosterone Deficiency
Treatment Options
We believe a large portion of men with low testosterone (T) remain untreated because of a lack of awareness of low T and dissatisfaction with currently available T-replacement therapies. These therapies, which include T-gels, T-patches, T-injectables, oral methyltestosterone, or methyl-T, buccal patches and subcutaneous injectable pellets, suffer from limitations related to safety and ease of use.
For example, T-gels carry a “black box warning” because of their risk of unsafe transference of T to children. Further, existing oral T formulations are associated with liver toxicity, inconsistent absorption, food effects and limited duration of effect, requiring frequent dosing.
There are several currently marketed non-oral T-replacement therapies to treat men with low T in the United States, including once-daily T-gels, T-injectables, once-daily T-patches, buccal patches and subcutaneous injectable pellets. We believe each of these existing therapies suffers from limitations related to safety and ease of use.
- T-gels: T-gels must be applied daily to broad sections of the upper arms, shoulders, or stomach. Beyond the mess, inconvenience and potential skin irritation, T-gels carry the risk of inadvertent and unsafe transference of T to women and children from contact with the hands or other areas on which the gel has been applied. Accidental exposure to T via a T-gel can cause premature puberty in children and changes in body hair or increased acne in women. The FDA requires a “black box warning” for these products due to the potentially severe consequences of T transference to children. Despite these concerns, two T-gels accounted for 84% of the over $1.6 billion total sales of T-replacement therapies in the United States in 2011: AndroGel®, marketed by Abbott, with $1.1 billion in sales; and Testim®, marketed by Auxilium, with $243 million in sales, according to IMS Health.
- T-injectables: Testosterone injections contain a T prodrug, such as T-enanthate, or TE, or T-cypionate dissolved in oil, and are given intramuscularly every two to three weeks, typically into the muscle of the buttocks. Intramuscular injections of T may be painful and generally require a visit to a physician’s office for administration. Testosterone injections can also result in serum T levels in excess of the upper limit of normal, which can ultimately increase the risk of stroke and gynecomastia, which is the abnormal enlargement of breasts due to conversion of excess T to estradiol. Finally, because men on this form of T-replacement are subject to wide-ranging levels of T between injections, they sometimes experience troublesome mood swings.
- T-patches: These medicated patches contain T and are applied daily to different skin locations on the body. Common side effects associated with T-patches are itching, irritation or discomfort at the application site. Consequently, it is recommended that the patch not be applied to the same site more than once a week.
- Other T delivery methods: In addition to the delivery methods described above, buccal patches and subcutaneous injectable pellets are sometimes used in T-replacement therapy. The buccal patch is a small, non-biodegradable patch that is placed twice daily to a hypogonadal man’s gums. Testosterone passes from the patch through the gums into the bloodstream. The primary problem with this route of T-replacement is that the patch does not always adhere properly and must be spit out if it becomes dislodged. When a patch is not in place, T-replacement therapy is not active. Testosterone in the form of subcutaneously injectable pellets is also available. These pellets degrade at a constant rate over time, often over three to four months, providing T to the user. A surgical procedure is required for implantation, and there is risk that the body will extrude the pellets. Also, if T-replacement therapy is stopped for any reason, the pellets must be removed surgically.