Degarelix (Firmagon)
Degarelix Acetate (N-acetyl-D-Nal(2)-D-Cpa-D-Pal(3)-Ser-Aph(Hor)-D-Aph(Cbm)-Leu-ILys-Pro-D-Ala-NH2)
Approved status applies to specific products, routes, and indications, not every use context discussed online.
An FDA-approved monthly injection (Firmagon) for advanced prostate cancer that rapidly lowers testosterone levels within days, helping slow cancer growth. Unlike some older treatments, it avoids an initial temporary spike in testosterone that can briefly worsen symptoms.
Safety Summary
In the CS21 Phase III trial (n=207 degarelix, n=201 leuprolide), the overall adverse event rate was 79% for degarelix vs 78% for leuprolide (PMID 19035858). Injection site reactions occurred in 35% of degarelix patients vs <1% leuprolide (pain 28%, erythema 17%, swelling 6%, induration 4%, nodule 3%), mostly transient and mild-to-moderate. Hot flashes: 26% degarelix vs 21% leuprolide. Liver enzyme elevations: 10% vs 5%, mostly Grade 1-2 and reversible. In the extension study (median 43 months, n=385), injection site infections including abscess occurred in 1% of patients (FDA Label). Anti-degarelix antibody development was observed in 10% of patients at 1 year but did not affect efficacy or safety (FDA Label). The 2025 meta-analysis (PMID 41216753) confirmed higher overall AE rate with degarelix (RR 1.07, p<0.001) but no increase in severe complications (RR 0.89, p=0.43) or death (RR 0.64, p=0.16). A 2026 FAERS analysis identified 53 previously unlabeled AE signals including interstitial lung disease, cardiac failure, osteoporotic fracture, and hyperkalemia (PMID 41776145).
Clinical check-in
If real-world use or exposure is being considered, review potential interactions, contraindications, and monitoring needs with a licensed clinician rather than relying on summary copy alone.
Sources: [1-20]