Testosterone Dysregulation and Erectile Dysfunction Associated with Teprotumumab Infusions: A Case Report
Author: Sri Meghana Konda
Base Hospital / Institution: Mass Eye and Ear / Harvard Medical School
ePoster presentation
Abstract ID: 25-474
Purpose
Teprotumumab is an insulin-like growth factor 1 (IGF1) receptor antagonist approved to treat thyroid eye disease (TED). It has been linked to side effects like irregular menstruation. We report a patient who developed testosterone dysregulation during teprotumumab treatment.
Methods
Retrospective case report.
Results
52-year-old male presented with proptosis, eyelid swelling, and conjunctival injection. Exam showed left eye proptosis, eyelid retraction/erythema/edema, and retropulsion resistance. Clinical activity score (CAS) was 4. Humphrey 30-2 perimetry was normal. Orbital computed tomography showed left levator enlargement. Thyroid function tests 1 month prior to presentation were normal. Thyroid-stimulating immunoglobulin (TSI) was 396 (normal < 140). Teprotumumab infusions were started. After 5 doses CAS reduced to 0, but he developed erectile dysfunction (ED) and low libido. His endocrinologist began to monitor testosterone. Testosterone levels (normal 300-890) were low during treatment (199 at 5 months, 193 at completion) and recovered post treatment (318 at 4 months, 371 at 9 months). Hypogonadal symptoms resolved; TED remained inactive. Nine months post treatment, TED recurred (CAS 3, TSI 429), with significant diplopia requiring a temporary work leave. Despite 6 IV methylprednisolone doses (500 mg each), symptoms worsened (CAS 7), prompting 2nd teprotumumab course. After 3rd infusion, he experienced ED and low libido again. Testosterone dropped from 420 pretreatment to 257 at 2 months. Testosterone cypionate (100 mg every 10 days) was started, leading to testosterone normalization (498). After completing teprotumumab, testosterone was tapered. Prostate specific antigen 1 month post completion was normal.
Conclusion
This highlights potential hormonal side effects of teprotumumab in men. It may disrupt testosterone regulation, as evidenced by the temporal relationship between infusions and testosterone decline. IGF1 inhibition may impair Leydig cell function which reduces testosterone. Clinicians should assess for hypogonadal symptoms and consider hormonal monitoring.
Additional Authors
| First name | Last name | Base Hospital / Institution |
|---|---|---|
| Lisa | Lin | Mass Eye and Ear / Harvard Medical School |
| Suzanne | Freitag | Mass Eye and Ear / Harvard Medical School |
