Treatment adherence higher with testosterone undecanoate vs. testosterone cypionate
Men prescribed long-acting testosterone undecanoate injections had a higher adherence to therapy at 1 year compared with those receiving short-acting testosterone cypionate injections, according to study findings.
In an analysis of retrospective data from more than 122,000 men in the U.S., adherence rates in men receiving testosterone undecanoate (Aveed, Endo Pharmaceuticals) therapy were similar to those receiving testosterone cypionate for the first 6 months of treatment. Adherence rates differed from 7 to 12 months, with only 8.2% of those receiving testosterone cypionate continuing treatment at 12 months compared with 41.9% for testosterone undecanoate.
“The data suggest a more convenient form of testosterone therapy, such as with long-acting injections, is of considerable importance to the willingness of men with testosterone deficiency to stay on treatment,” Abraham Morgentaler, MD, associate professor of surgery, part-time in the division of urology at Beth Israel Deaconess Medical Center, Harvard Medical School, told Healio. “There is growing awareness that testosterone deficiency is an important medical condition, and that treatment with testosterone therapy improves not only symptoms, but also has general health benefits, such as improvements in glycemic control, reductions in fat mass and increases in muscle mass, mood, bone density and unexplained anemia. Yet those benefits can only be achieved if men stay on treatment.”
Morgentaler and colleagues conducted a retrospective cohort study of data from the Veradigm database, which consists of electronic health record data from ambulatory facilities in the U.S. Men aged 18 years and older who initiated testosterone undecanoate or testosterone cypionate injections from 2014 to 2018 were included. Data were collected in 6-month increments through July 2019. Maintenance of treatment was defined as a gap no more than twice the recommended dosing interval of 20 weeks for testosterone undecanoate or 4 weeks of testosterone cypionate between prescriptions. Treatment adherence was assessed from the date of the first injection until discontinuation, a prescription switch or the end date of the originally prescribed testosterone therapy. Testosterone nonadherence in the testosterone undecanoate group was defined as a gap of more than 42 days between the first prescription end date and the second prescription start date, or a gap of more than 105 days between future prescriptions. Nonadherence in the testosterone cypionate group was defined as a gap of more than 21 days between the end of one prescription and the start of the next. Researchers assessed changes in body weight, BMI, blood pressure, testosterone level and incidence of new cardiovascular events and risk factors from 3 months prior to the first injection to 12 months after treatment was initiated.
The findings were published in Androgens: Clinical Research and Therapeutics.
Adherence rates diverge after 6 months
There were 948 men prescribed testosterone undecanoate and 121,852 men prescribed testosterone cypionate in the study cohort. At baseline, 18.9% of the testosterone undecanoate group and 41.2% of the testosterone cypionate group did not have a diagnosis of hypogonadism. Mean free testosterone was higher at baseline in those prescribed testosterone undecanoate compared with testosterone cypionate (65.2 pg/mL vs. 38.8 pg/mL; P < .001).
During the first 6 months, adherence rates were similar between the two groups. During months 7 to 12, the testosterone undecanoate group had a higher adherence rate than the testosterone cypionate group (82% vs. 40.8%; P < .001). A higher percentage of men in the testosterone undecanoate group maintained their original testosterone therapy (41.9% vs. 8.2%; P < .001) and fewer discontinued testosterone (33.8% vs. 89.9%; P < .001) at 12 months compared with men taking testosterone cypionate.
“Surprisingly, only 8.2% of men on testosterone cypionate injections remained on treatment at the end of 1 year,” Morgentaler said. “This remarkably low value for the most frequently used form of testosterone therapy in the U.S. means that testosterone-deficient men are not being adequately treated.”
Significant changes in testosterone concentrations
Those receiving testosterone undecanoate had a larger mean change in total testosterone (171.7 ng/dL vs. 59.6 ng/dL; P < .001) and free testosterone (25.4 pg/mL vs. 3.7 pg/mL; P = .001) at 12 months compared with those receiving testosterone cypionate. Variability in total testosterone levels was lower with testosterone undecanoate vs. testosterone cypionate.
Mean change in weight, BMI and BP was similar between the groups at 12 months. The testosterone undecanoate group has a higher percentage of men with newly diagnosed erectile dysfunction and obesity at follow-up, whereas the testosterone cypionate group had a higher percentage of men with diagnosed hypertension, congestive heart failure and chronic pain.
Morgentaler said more research is needed to understand why most men taking testosterone cypionate injections discontinue treatment within 1 year.
“One can speculate that the much greater use of testosterone undecanoate injections in this study at 12 months was due to the convenience of a long-acting formulation, but it would be helpful to know whether this may be due to other factors, such as cost, distaste for frequent self-injection, lack of observable improvement in symptoms, or something else,” Morgentaler said.
For more information:
Abraham Morgentaler, MD, can be reached at dr.morgentaler@menshealthboston.com.
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