What is the preferred treatment between Enzalutamide (generic name) and Bicalutamide (generic name) for a patient with prostate cancer who has undergone Coronary Artery Bypass Grafting (CABG)?

Enzalutamide vs Bicalutamide for Post-CABG Prostate Cancer Patient

Enzalutamide is strongly preferred over bicalutamide for a post-CABG prostate cancer patient due to superior efficacy and a more favorable cardiovascular risk profile. 1, 2

Efficacy Comparison

• Enzalutamide demonstrates significantly better progression-free survival compared to bicalutamide in castration-resistant prostate cancer patients, with a median time to progression of 15.7 months with enzalutamide versus 5.8 months with bicalutamide (HR 0.44) 1, 3
• The STRIVE trial showed enzalutamide reduced the risk of progression or death by 76% compared with bicalutamide (HR 0.24; 95% CI, 0.18–0.32) 1
• The National Comprehensive Cancer Network (NCCN) designates enzalutamide as a category 1, preferred treatment option for patients without prior novel hormone therapy in the metastatic castration-resistant prostate cancer setting 1

Cardiovascular Considerations for Post-CABG Patients

• Enzalutamide has not been associated with significant hypercholesterolemia, unlike bicalutamide, making it more suitable for post-CABG patients who are at higher risk for cardiovascular events 2
• While enzalutamide was associated with slightly higher rates of major adverse cardiovascular events (5% vs 3%) compared to placebo in the PROSPER trial, this difference is less concerning than bicalutamide's known effects on lipid profiles 1, 2
• Bicalutamide requires regular monitoring of lipid profiles, particularly in patients with existing cardiovascular disease like those with history of CABG 4

Age and Comorbidity Considerations

• In the TERRAIN trial, enzalutamide improved clinical outcomes versus bicalutamide regardless of age, though increased falls and cardiac events in patients ≥75 years suggest caution in older patients with significant comorbidities 5
• For post-CABG patients, the cardiovascular risk profile becomes particularly important, making enzalutamide's lack of significant impact on cholesterol levels advantageous 2

Side Effect Profiles

• Common side effects of enzalutamide include fatigue (33%), hypertension (12%), and mental impairment disorders (5%) 1
• Bicalutamide's side effect profile differs, with hypercholesterolemia being a particular concern for post-CABG patients 4
• The NCCN acknowledges that bicalutamide can still be considered in some patients due to different side effect profiles and cost considerations, despite enzalutamide's superior efficacy 1, 6

Treatment Algorithm for Post-CABG Prostate Cancer Patient

1. First choice: Enzalutamide 160 mg daily - Preferred due to superior efficacy and more favorable cardiovascular profile for post-CABG patients 1, 2

2. Second choice: Bicalutamide 50 mg daily - Consider only if:

   • Patient cannot tolerate enzalutamide side effects 1
   • Cost is a significant barrier (enzalutamide is more expensive) 2
   • If selected, implement aggressive lipid monitoring and management 4

Monitoring Recommendations

• For patients on enzalutamide:

  • Monitor for fatigue, hypertension, and mental status changes 1, 2
  • No food restrictions required; concurrent prednisone permitted but not required 1

• For patients on bicalutamide (if selected):

  • Regular lipid profile monitoring is essential, especially in post-CABG patients 4
  • Consider statin therapy, with pravastatin being preferred as it doesn't share the CYP3A4 metabolic pathway with bicalutamide 4

Important Considerations

• Patients receiving either medication should continue LHRH agonist/antagonist therapy 2
• In post-CABG patients specifically, the cardiovascular safety profile should be prioritized alongside cancer control efficacy 2, 4
• The higher cost of enzalutamide may be justified by its superior efficacy and more favorable cardiovascular profile in this high-risk population 1, 2