Post-market safety and efficacy profile of subcutaneous testosterone enanthate-autoinjector: a cohort analysis

A subcutaneous testosterone enanthate-autoinjector (SCTE-AI) was recently approved by the Food and Drug Administration for patient-administered weekly testosterone replacement therapy (TRT). From January 2019 to October 2019, 110 hypogonadal men were treated with SCTE-AI at two institutions. Patients were assessed in a pretherapy visit prior to receiving SCTE-AI and re-assessed 6 weeks after treatment initiation. Patients with a history of prostate cancer were excluded. Trough serum total testosterone (TT), estradiol (E2), prostate-specific antigen (PSA), and hematocrit (HCT) levels were collected at clinic visits. Therapeutic phlebotomy was recommended for HCT > 54%, and treatment was discontinued for significant increases in PSA as well as for significant treatment-related adverse events. Values from each visit were compared with univariate analysis. 110 patients completed the 6 weeks of observation with a mean age of 40.3 (SD: 10.5). TT significantly rose from 246.6 ng/dL (SD:113.3) pretherapy to 538.4 ng/dL (SD: 209.3) at 6 weeks (p < 0.001). Post-therapy, 101/110 (91.8%) of patients had TT > 300 ng/dL. No patients had HCT > 54%. 74 patients (70.5%) had PSA increase with only 3 (2.9%) experiencing an increase >1.0 ng/dL. There was a significant increase in mean PSA from 1.07 ng/dL (SD: 0.8) pretherapy to 1.18 ng/dL (SD: 0.9) at 6 weeks (p = 0.01). One patient had immediate treatment cessation following diagnosis of prostate cancer. This is the largest non-industry sponsored safety and efficacy profile of SCTE-AI application in urology clinics. After 6 weeks of observation, TT levels increased significantly without any reports of adverse events. SCTE-AI is a safe and effective alternative delivery system of TRT.