Needle-Free Subcutaneous Self Injection for Testosterone Supplementation Therapy
http://www.aua2015.org/abstracts/abstractprint.cfm?id=PD37-06
Introduction and Objectives - Various modalities for testosterone supplementation therapy (TST) are in wide use with an increasing frequency. Each has unique disadvantages with regard to fluctuating testosterone (T) levels, pain, or potential for unintentional topical transfer.
While IM testosterone cypionate (Tc) has an abundance of clinical experience, subcutaneous (sc) injections of Tc has not been adequately studied. Similarly, needle-free therapy has not been evaluated as an option despite decades of use.
We investigated the feasibility, pharmacokinetics, and efficacy of self administered needle-free sc injection of Tc as a viable treatment for TST.
We hypothesized that needle-free delivery of TST would reach efficacious T levels, be well tolerated, improve symptoms and be self administered with negligible pain.
Methods - Informed consent and IRB approval was obtained to enroll 24 symptomatic hypogonadal men in two consecutive proof-of-concept prospective studies.
In the first 30 days, 14 men injected 25mg/day (QD25) and 10 men injected 50mg Monday, Wednesday, and Friday with weekends off (MWFWO50). Serum T levels were obtained at close intervals to determine both optimal Tc dose and injection frequency.
In the second study, data was combined from QODWO50 dosing at Day 60 and Day 90. Validated pain scores and the Aging Male Symptom (AMS) score were recorded Day 0 and Day 30.
Results - Twenty-four total hypogonadal men enrolled in the studies with an average T level of 171ng/dL.
Phase I of the study demonstrated therapeutic levels in all men both QD25 and MWFWO50 dosing by Day 14. Mean T levels at Day 30 for QD25 and QODWO50 dosing was 846ng/dL and 585ng/dL, respectively. Four of 14 QD25 men were supraphysiologic at Day 30.
To mitigate this observed trend of rising T levels 10 men from the Phase I QD25 cohort were converted to QODWO50 at Day 30. All men in the QODWO50 program were eugonadal at Day 60 (616ng/mL ± SD 179) and 90 (586ng/mL ± SD 159).
In addition, (20/20) men had statistically significant improvement in AMS score and reported minimal pain (p≤0.001). Estradiol and free/total T levels increased in accordance with historically published Tc IM treatments. No adverse events occurred.
Conclusions - Needle-free delivery of commercially available testosterone cypionate is efficacious and provides physiologic ranges of T serum levels in men whom self inject subcutaneously three times weekly with 50mg.
The benefits of flexible dosing, self administration, maintenance of more consistent T serum levels, minimal pain, and reduced risk of interpersonal transfer makes this novel approach worth evaluating on a larger scale.