Erleada (apalutamide) and Xtandi (enzalutamide) are both anti-androgen medicines used to treat types of prostate cancer.

What they treat

Erleada treats two types of prostate cancer and Xtandi treats three types of prostate cancer.

Erleada treats:

• Metastatic castration-sensitive prostate cancer (mCSPC)
• Non-metastatic castration-resistant prostate cancer (nmCRPC)

Xtandi treats:

• Metastatic castration-sensitive prostate cancer (mCSPC)
• Non-metastatic castration-resistant prostate cancer (nmCRPC)
• Metastatic castration-resistant prostate cancer (mCRPC)

How well do they work?

Separate studies have been done for enzalutamide (ARCHES trial, PROSPER trial, PREVAIL trial, TERRAIN trial and AFFIRM trial ) and apalutamide (SPARTAN trial and TITAN trial). The figures and information below are not from direct comparison studies, they are from individual drug trials.

Metastatic CSPC

Enzalutamide

• The ARCHES trial looked at enzalutamide used for metastatic CSPC and how many patients had their disease progress from when study began until 24 weeks after the study finished. The enzalutamide group had 18.7% less disease progression when compared to the placebo group (placebo 32.1% - enzalutamide 13.4% = 18.7%).

Apalutamide

• TITAN clinical trial studied apalutamide used for metastatic CSPC and how many patients had their disease progress during the clinical trial. The Apalutamide group had 26% of the patients with disease progression compared to 44% of the placebo patients, which means the apalutamide group had 18% less disease progression compared to the placebo group (placebo 44% - Apalutamide 26% = 18%).

Non-metastatic CRPC

Enzalutamide

• In the PROSPER clinical trial enzalutamide increased the time before patients cancer metastasis occurred or death by 21.9 months when compared to placebo (Enzalutamide 36.6 - placebo 14.7 = 21.9 months).
• The PROSPER clinical trial showed enzalutamide increased overall survival by 10.7 months when compared to placebo (Enzalutamide 67.0 - placebo 56.3 = 10.7 months).

Apalutamide

• In the SPARTAN clinical trial apalutamide increased the median time before patients cancer metastasis occurred or death by 24.3 months when compared to placebo (apalutamide 40.5 - placebo 16.2 = 24.3 months).
• The SPARTAN clinical trial showed apalutamide increased overall survival by 14.0 months when compared to placebo (apalutamide 73.9 - placebo 59.9 =14.0 months).

Metastatic CRPC Following Chemotherapy

Enzalutamide

• Enzalutamide was used for metastatic CRPC following chemotherapy in the AFFIRM trial which showed a statistically significant improvement in overall survival of an extra 4.8 months when compared to placebo.(Enzalutamide 18.4 - placebo 13.6 =4.8 months)
• Enzalutamide was used for metastatic CRPC in patients who have not had docetaxel-based chemotherapy in the PREVAIL trial. This trial showed that Enzalutamide increased the median survival by 4 months when compared to placebo (Enzalutamide survival 35.3 months - placebo survival 31.3 months = 4 months).

How are they taken?

• Erleada is available as a tablet and Xtandi is available as tablets and capsules.
• Both medicines are taken daily, swallowed whole and can be taken with or without food.
• Erleada tablets can be mixed with applesauce for patients who have difficulty in swallowing, for more information on this see Alternative Method of Administration.
• Both medicines need to be taken with a gonadotropin-releasing hormone (GnRH) analog or patients should have had a bilateral orchiectomy.

Side effects

Both enzalutamide (TERRAIN clinical trial) and apalutamide (SPARTAN clinical trial) in their clinical trials had some of the same side effects that occured in more than 10% of patients including:

• Fatigue or lack of strength
• Joint and muscle pain
• Nausea
• Decrease weight
• Diarrhea
• Hypertension
• Hot flush

Enzalutamide had the additional side effects of:

• Constipation
• Upper respiratory tract infection
• Back pain

Apalutamide had other side effects including:

• Swelling of extremities
• Falls
• Fracture
• Rash
• Decreased appetite

Bottom line

• Erleada and Xtandi are both oral anti-androgen medicines used to treat prostate cancer, Erleada treats 2 types of prostate cancer and Xtandi treats 3 types of prostate cancer.
• Erleada and Xtandi are both oral medications taken as a tablet or capsule.
• Your doctor will look at your personal clinical information and situation and discuss with you the best medication option for you.