A Patient Guide

Author: Paola Larrabure, Pharma Content Manager  |  Clinical Reviewer: Julia Kravtsova, PharmD, Head Patient Navigator

Last Reviewed: April 2026

The timeline above captures one of the most remarkable stretches of cancer drug development in modern medicine. For more than half a century, androgen deprivation therapy stood essentially alone as the backbone of advanced prostate cancer care. Then, in the past fifteen years, the treatment landscape transformed — driven largely by a class of oral medications called androgen receptor inhibitors (ARIs), sometimes also called androgen receptor pathway inhibitors (ARPIs).

This guide was written for patients and caregivers navigating an advanced prostate cancer diagnosis. It explains what androgen receptor inhibitors are, the four FDA-approved medications in this class, the research behind combination regimens like triplet therapy, and how to prepare for an informed conversation with your oncologist. It is intended for educational purposes and does not replace the personalized medical advice of your oncology team.

What are androgen receptor inhibitors?

Prostate cancer cells depend on male hormones called androgens — primarily testosterone — to grow. Androgen deprivation therapy (ADT) has been the backbone of advanced prostate cancer treatment for over eight decades. ADT works by lowering the amount of testosterone your body produces. However, even when testosterone levels are very low, some prostate cancer cells continue to find ways to grow, because testosterone can still activate a protein inside the cancer cell called the androgen receptor.

Androgen receptor inhibitors are oral medications that either block the androgen receptor directly or reduce androgen production even further. By targeting this pathway, ARIs cut off another way cancer cells keep growing — even when testosterone is already low from ADT. According to the American Cancer Society, these medications are almost always used in addition to ADT, not as a replacement for it. Your oncologist may describe this as a “combination” or “treatment intensification” approach.

How androgen receptor inhibitors work

There are two main ways medications in this broader class can interfere with androgen signaling:

• Blocking the receptor directly. Enzalutamide, apalutamide, and darolutamide attach to the androgen receptor and prevent testosterone from binding to it. This stops the signal that tells the cancer cell to grow.
• Reducing androgen production. Abiraterone works differently. Rather than blocking the receptor, it inhibits an enzyme called CYP17 that the body uses to make testosterone and other androgens. This lowers androgen levels throughout the body, including inside the tumor itself. Because abiraterone can lower levels of other important hormones too, it is always given together with a low-dose steroid (usually prednisone or methylprednisolone) to prevent certain side effects.

Both approaches share the same goal: to slow the growth of prostate cancer by disrupting the hormone signals that feed it.

The stages of prostate cancer where ARIs are used

Prostate cancer is a heterogeneous disease, meaning it behaves differently from one patient to another. Treatment decisions depend heavily on which stage the cancer is in. Here are the advanced stages where androgen receptor inhibitors play a central role:

Metastatic castration-sensitive prostate cancer (mCSPC)

Also called metastatic hormone-sensitive prostate cancer (mHSPC). This is prostate cancer that has spread beyond the prostate gland but still responds to hormone-lowering therapy. For patients newly diagnosed with mCSPC, current standard of care involves ADT combined with either an androgen receptor pathway inhibitor, chemotherapy (docetaxel), or a combination of both — a regimen sometimes called “triplet therapy.”

Non-metastatic castration-resistant prostate cancer (nmCRPC)

This is prostate cancer that has not yet spread to other parts of the body, but is no longer controlled by ADT alone — meaning the cancer is growing even though testosterone levels are low. For patients at high risk of their cancer spreading (usually measured by PSA doubling time), the FDA has approved three androgen receptor inhibitors — apalutamide, enzalutamide, and darolutamide — to be added to ADT.

Metastatic castration-resistant prostate cancer (mCRPC)

This is the most advanced stage, where the cancer has spread and stopped responding to ADT alone. Abiraterone and enzalutamide are both approved in this setting, often used sequentially with other therapies such as chemotherapy, radiopharmaceuticals, or targeted therapies depending on the patient’s biomarkers and prior treatment history.

The four androgen receptor inhibitors approved in the United States

The following medications are currently approved by the FDA for the treatment of advanced prostate cancer. Each has its own approval history and set of indications. Your oncologist will determine which is most appropriate for your specific disease stage and health profile.

Abiraterone acetate (Zytiga, Yonsa, and generics)

Abiraterone was the first of the next-generation androgen-targeted therapies to be approved, in April 2011. It is a CYP17 inhibitor that lowers androgen production throughout the body. Abiraterone is approved, in combination with prednisone, for metastatic castration-resistant prostate cancer and for metastatic high-risk castration-sensitive prostate cancer. It is now available as a generic, which can substantially reduce out-of-pocket cost. A fixed-dose combination with niraparib (Akeega) is also approved for patients with BRCA-mutated mCRPC.

→ Learn about Zytiga (abiraterone) copay assistance

Enzalutamide (Xtandi)

Enzalutamide was approved by the FDA in 2012 for metastatic castration-resistant prostate cancer. Its approved indications have since expanded to include non-metastatic castration-resistant prostate cancer, metastatic castration-sensitive prostate cancer, and — as of November 2023 — non-metastatic castration-sensitive prostate cancer with high-risk biochemical recurrence. Enzalutamide directly blocks the androgen receptor and is taken as an oral tablet once daily.

Apalutamide (Erleada)

Apalutamide was approved by the FDA in February 2018 for non-metastatic castration-resistant prostate cancer, becoming the first prostate cancer treatment approved based on improving metastasis-free survival. Its approval was expanded in September 2019 to include metastatic castration-sensitive prostate cancer. Apalutamide directly blocks the androgen receptor and is taken as an oral tablet once daily.

Darolutamide (Nubeqa)

Darolutamide was approved by the FDA on July 30, 2019, initially for non-metastatic castration-resistant prostate cancer. Its approved indications now include metastatic castration-sensitive prostate cancer, both as a single agent with ADT and in combination with docetaxel chemotherapy. Darolutamide is a structurally distinct androgen receptor inhibitor with low blood-brain barrier penetration, and is taken as an oral tablet twice daily with food.

→ Learn about Nubeqa (darolutamide) copay assistance

Triplet therapy: what the research shows

One of the most significant shifts in advanced prostate cancer treatment over the past several years has been the emergence of triplet therapy for metastatic hormone-sensitive prostate cancer. Triplet therapy refers to combining three treatments together: ADT + an androgen receptor pathway inhibitor + docetaxel chemotherapy. Research continues to explore which patients benefit most from this intensified approach.

The ARASENS trial (darolutamide triplet therapy)

Published in the New England Journal of Medicine in 2022, the ARASENS trial (Smith et al.) was a randomized, double-blind phase 3 study evaluating darolutamide plus ADT and docetaxel versus placebo plus ADT and docetaxel in patients with mHSPC. The trial demonstrated a significant overall survival benefit with the addition of darolutamide. This trial formed the basis for the FDA’s approval of darolutamide in the mHSPC setting.

The PEACE-1 trial (abiraterone triplet therapy)

Also published in 2022, the PEACE-1 trial (Fizazi et al., Lancet) evaluated abiraterone plus prednisone added to ADT and docetaxel in de novo mCSPC. PEACE-1 demonstrated improvements in both overall survival and radiographic progression-free survival for triplet therapy compared to ADT plus docetaxel alone.

The ARANOTE trial (darolutamide doublet — no chemotherapy)

Published in the Journal of Clinical Oncology in September 2024, ARANOTE (Saad et al.) was a randomized, double-blind phase 3 trial of darolutamide plus ADT without docetaxel in mHSPC. At 24 months, the trial showed improved radiographic progression-free survival (70.3% versus 52.1% with placebo plus ADT), providing an important new option for patients who may not be candidates for chemotherapy.

The ARAAT real-world study

Presented at the 2025 ASCO Genitourinary Cancers Symposium, the ARAAT study (McKay et al., Poster 66) examined real-world outcomes of triplet therapy regimens in U.S. oncology practice. The retrospective cohort included 242 patients with mHSPC from the ConcertAI Patient360 database, comparing those who initiated darolutamide-based triplet therapy with those who initiated abiraterone-based triplet therapy. The investigators reported differences in treatment discontinuation rates, time to progression to castration-resistance, and PSA response patterns. The investigators concluded that “the ARAAT real-world study strengthens the evidence supporting the combination of darolutamide with ADT and docetaxel as an effective treatment for mHSPC.” Research sponsored by Bayer AG.

How oncologists choose among these medications

This is one of the most common questions patients ask, and the honest answer is that the choice is highly individualized. A peer-reviewed review in the medical literature notes that for the newer androgen receptor inhibitors, there is no head-to-head evidence of superiority of one drug over another across all settings. Therapeutic choice depends on the safety profile in relation to the individual patient, their comorbidities, and their clinical condition.

Factors oncologists consider include:

• Stage of your prostate cancer. Not every medication is approved for every stage. Your oncologist starts by matching your disease setting (mCSPC, nmCRPC, or mCRPC) with the medications that are FDA-approved for it.
• Disease volume and risk. In metastatic hormone-sensitive disease, whether the cancer is “high-volume” or “low-volume” (based on the number and location of metastases) affects whether triplet therapy or doublet therapy is most appropriate.
• Your other medical conditions. If you have a history of heart disease, seizures, diabetes, liver disease, or kidney disease, some medications may be more appropriate than others.
• Drug interactions. Androgen receptor inhibitors can interact with many common medications, including certain heart, blood pressure, cholesterol, and anti-seizure drugs. Your oncology team will review every medication and supplement you take.
• Fitness for chemotherapy. Triplet therapy requires that a patient be fit enough for docetaxel infusions. If chemotherapy is not an option, a doublet regimen (ADT plus an ARPI) is typically chosen.
• Side effect profile. Different medications have different patterns of side effects. What matters most is a side effect profile that you can tolerate long-term, since these medications are often taken for months or years.
• Insurance coverage and access. Specialty medications can have significant out-of-pocket costs, and availability of copay assistance or patient assistance programs can play a role in the practical decision.

In many advanced prostate cancer settings, multiple androgen receptor pathway inhibitors are considered Category 1 recommendations by the NCCN Guidelines — meaning they are all supported by strong evidence. The specific choice depends on each patient’s individual circumstances, and should be made in conversation with the oncology team.

Common side effects and what to monitor for

Every androgen receptor inhibitor has its own side effect profile, but some categories of side effects are common across the class because they stem from the underlying mechanism of lowering or blocking androgen activity. Your oncology team will review all of this with you before starting treatment. Commonly discussed categories include:

• Fatigue — often the most commonly reported side effect
• Hot flashes — related to low testosterone
• Falls and fractures — androgen-targeted therapies can affect bone health and balance
• Cardiovascular effects — including high blood pressure and, in some patients, ischemic heart disease
• Cognitive or mood changes
• Seizures — rare but reported with some medications in this class
• Metabolic effects — changes in cholesterol, blood sugar, and body composition

Some medications require additional specific monitoring. For example, abiraterone requires monitoring of liver function, blood pressure, and potassium levels, and patients take a low-dose steroid alongside it to prevent certain side effects. The other three medications have their own monitoring requirements that your oncology team will explain. Darolutamide has been studied for its lower blood-brain barrier penetration profile compared to other receptor-blocking agents; your oncologist can discuss whether this is a relevant factor for your treatment plan.

Always report new or worsening symptoms to your oncology team right away. Do not stop your medication without first speaking with your oncologist.

Questions to ask your oncologist

Preparing for your next appointment can help you feel more confident about your treatment plan. Here are questions to consider bringing with you:

You can print this list or take a photo of it to bring to your appointment. Thoughtful questions help your oncology team deliver better care.

Affording your prostate cancer medication

Advanced prostate cancer medications are specialty medications — high-cost drugs with special handling and dispensing requirements. Even with insurance, out-of-pocket costs can be significant. The good news is that several layers of financial assistance exist, and a specialty pharmacy team can help you access them.

Depending on your insurance and income situation, you may be eligible for:

• Manufacturer copay cards — for patients with commercial insurance, many manufacturers offer copay programs that can reduce out-of-pocket costs substantially. Government-insured patients (Medicare, Medicaid, TRICARE, VA) are not eligible by federal law.
• Patient assistance programs — for uninsured or underinsured patients who meet financial need criteria, manufacturers may provide medication at no cost.
• Foundation grants — independent nonprofit foundations such as the Patient Access Network (PAN) Foundation, HealthWell Foundation, and CancerCare offer grants specifically for prostate cancer patients, including those with Medicare coverage.
• Generic options — for medications like abiraterone that are now available generically, the cost difference versus brand can be substantial. Ask your oncology team whether generic is an appropriate option for your situation.

At QuickRx Specialty Pharmacy, our dedicated patient navigator team — led by Julia Kravtsova, PharmD — handles every copay card enrollment, patient assistance application, and foundation grant submission on your behalf, at no cost to you. Our goal is for cost never to be the reason you can’t start or stay on the treatment your oncologist recommends.

We dispense all four FDA-approved androgen receptor inhibitors discussed in this article — abiraterone, enzalutamide, apalutamide, and darolutamide — and ship nationwide with free temperature-controlled packaging where required.

Key takeaways

• Prostate cancer treatment has evolved dramatically since the 1940s, with an especially rapid pace of new therapy approvals over the past fifteen years.
• Androgen receptor inhibitors are an important class of oral medications used to treat advanced prostate cancer. They are almost always used together with androgen deprivation therapy (ADT).
• Four medications in this broader class are currently FDA-approved: abiraterone, enzalutamide, apalutamide, and darolutamide.
• Different medications are approved for different stages of advanced prostate cancer, and choice within a stage depends on individual patient factors — not on a universal ranking.
• Triplet therapy (ADT + ARPI + chemotherapy) and doublet therapy (ADT + ARPI) are both supported by phase 3 trial evidence in metastatic hormone-sensitive prostate cancer. The choice depends on disease characteristics and patient fitness.
• Shared decision-making between patient and oncology team is the standard approach. Patients benefit from coming to appointments prepared with questions.
• Copay assistance, patient assistance programs, and foundation grants can significantly reduce out-of-pocket cost. A specialty pharmacy team can help patients access every program they qualify for.

Sources and references

1. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Prostate Cancer, Version 3.2026. Available at: nccn.org/guidelines
2. U.S. Food and Drug Administration. Prostate Cancer: Symptoms, Tests and Treatments. Available at: fda.gov
3. American Cancer Society. Hormone Therapy for Prostate Cancer. Available at: cancer.org
4. National Cancer Institute. Drugs Approved for Prostate Cancer. Available at: cancer.gov
5. Benjamin DJ, Kalebasty AR. Characterization and Survival Benefit of Drug Approvals for Metastatic Prostate Cancer, 2004 to 2022. Cancer Control. PMC10845988.
6. Smith MR, Hussain M, Saad F, et al. Darolutamide and Survival in Metastatic, Hormone-Sensitive Prostate Cancer. N Engl J Med. 2022;386(12):1132-1142. (ARASENS)
7. Fizazi K, Foulon S, Carles J, et al. Abiraterone plus prednisone added to ADT and docetaxel in de novo mCSPC (PEACE-1). Lancet. 2022;399(10336):1695-1707.
8. Saad F, Vjaters E, Shore N, et al. Darolutamide with ADT in mHSPC from the phase III ARANOTE trial. J Clin Oncol. 2024.
9. McKay RR, Morgans AK, Khan N, et al. Clinical use and outcomes of ARPI triple therapy for mHSPC (ARAAT). Presented at: ASCO GU 2025, Poster 66.
10. Scaravilli M, et al. Practical implications of androgen receptor inhibitors for prostate cancer treatment. PMC11220289.