Apalutamide
Apalutamide is a second-generation androgen-receptor antagonist approved for non-metastatic castration-resistant and metastatic hormone-sensitive prostate cancer. Structurally related to enzalutamide, it delays metastasis and prolongs survival, with skin rash and thyroid effects among its more characteristic adverse events.
01 Overview
Marketed as Erleada, apalutamide blocks androgen-receptor signalling at multiple steps. Trials such as SPARTAN and TITAN established its benefit in delaying metastasis and improving survival.
Compared with enzalutamide it is associated with a notably higher rate of skin rash and with hypothyroidism, alongside the class-typical fatigue, falls, and fracture risk.
02 Mechanism
Binds the androgen receptor and inhibits androgen binding, nuclear translocation, and DNA binding, suppressing androgen-driven prostate cancer growth.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Prostate cancer | 240 mg/day | Oral | 240 mg once daily |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Delayed metastasisProlongs metastasis-free survival in non-metastatic CRPC. | Significant vs placebo | Clinical | |
| Improved overall survivalImproves survival in metastatic hormone-sensitive disease. | Survival benefit in RCTs | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Skin rashMaculopapular rash, occasionally severe, more frequent than with enzalutamide. | Moderate | Very common | Clinical | |
| HypothyroidismReduced thyroid hormone levels during treatment. | Mild | Common | Clinical | |
| Falls and fracturesIncreased fall and fracture rates, especially in older men. | Moderate | Common | Clinical |