YONSA is a CYP17 inhibitor indicated in combination with methylprednisolone for the treatment of patients with metastatic castration-resistant prostate cancer.

Before taking YONSA, tell your doctor about all of your medical conditions, including if you:

  • have heart problems
  • have liver problems
  • have diabetes
  • have a history of adrenal problems or have a history of pituitary problems
  • are receiving any other treatment for prostate cancer
  • are pregnant or planning to become pregnant. YONSA can cause harm to your unborn baby and miscarriage. Females who are pregnant should not handle YONSA tablets if broken, damaged, crushed, or without protection, such as gloves.
  • have a partner who is pregnant or may become pregnant. Males who have female partners who are able to become pregnant should use effective contraception during treatment with YONSA and for 3 weeks after the final dose of YONSA.
  • are breastfeeding or planning to breastfeed. It is not known if YONSA can pass into your breastmilk.
  • Tell your doctor about all the medicines you take, treatments you receive, prescriptions, over-the-counter medicines herbal supplements, and vitamins.
  • YONSA can interact with many other medicines.
  • You should not start or stop any medicine before you talk with the doctor that prescribed YONSA.
  • Keep a list of the medicines you use so, you can show them to your doctor or pharmacist.

How should I take YONSA?

  • Take YONSA and methylprednisolone exactly as your doctor tells you.
  • Take the prescribed dose of YONSA (1 time a day) and methylprednisolone (2 times a day).
  • YONSA contains abiraterone acetate. YONSA and other medicines that contain abiraterone acetate may not be the same.
  • Do not switch between YONSA and other medicines that contain abiraterone acetate unless your doctor tells you to.
  • Do not take YONSA and other medicines that contain abiraterone acetate on the same day.
  • If you do not have enough YONSA to take your full dose or if you have any other questions about YONSA, talk with your doctor or pharmacist.
  • Your doctor may change your dose of YONSA if needed.
  • Do not change or stop taking your prescribed dose of YONSA or methylprednisolone without talking with your doctor first.
  • Take YONSA with or without food.
  • Swallow the YONSA tablets whole with water and do not crush or chew the tablets.
  • If you miss a dose of YONSA or methylprednisolone, take your dose the following day. If you miss more than 1 dose, tell your doctor right away.
  • If you are receiving gonadotropin-releasing hormone (GnRH) therapy, you should continue your therapy during treatment with YONSA and methylprednisolone.
  • If you take too much YONSA, call your doctor or go to the nearest hospital right away.
  • Your doctor will do blood tests to check for side effects.

Dosage modification:

  • If you have moderate hepatic impairment (Child-Pugh Class B), the YONSA dosage will be reduced to 125 mg once daily. The doctor will also monitor ALT, AST, and bilirubin before starting the treatment, every week for the first month, every two weeks for the following two months of treatment, and monthly thereafter.
  • If you develop hepatotoxicity during treatment, stop using YONSA until recovery. The retreatment may be initiated at a reduced dose. If you develop severe hepatotoxicity, the doctor will tell you to discontinue the use of YONSA.

How should I store YONSA?

You can store YONSA at room temperature between 68°F to 77°F (20°C to 25°C).

What are the ingredients in YONSA?

Active ingredient: abiraterone acetate.
Inactive ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, sodium lauryl sulfate, sodium stearyl fumarate, butylated hydroxyanisole, butylated hydroxytoluene

What are the side effects or adverse reactions to using YONSA?

  • Musculoskeletal and connective tissue disorders
  • Joint swelling/ discomfort
  • Muscle discomfort
  • General Disorders
  • Edema
  • Vascular Disorders
  • Hot Flush
  • Hypertension
  • Gastrointestinal Disorders
  • Diarrhea
  • Dyspepsia
  • Infections and infestations
  • Urinary tract infection
  • Upper respiratory tract infection
  • Respiratory, thoracic, and mediastinal disorders
  • Cough
  • Renal and urinary disorders
  • Urinary frequency
  • Nocturia
  • Injury, poisoning, and procedural complications
  • Fractures
  • Cardiac disorders
  • Arrhythmia
  • Chest pain or chest discomfort
  • Cardiac failure

Warnings and Precautions:

High blood pressure (hypertension), fluid retention (edema), low blood potassium levels (hypokalemia), and irregular heartbeats can happen during treatment with YONSA

YONSA may cause hypertension, fluid retention, and hypokalemia, as a consequence of increased mineralocorticoid levels resulting from CYP17 inhibition. Your doctor will monitor you for hypertension, fluid retention, and hypokalemia, at least once a month and control it before treatment.The safety of YONSA in patients with left ventricular ejection fraction has not been established because these patients were excluded from these randomized clinical trials.

Adrenocortical Insufficiency (Adrenal problems)

Adrenal insufficiency occurred in two randomized clinical studies in 0.5% of patients taking abiraterone acetate and in 0.2% of patients taking a placebo. Adrenocortical insufficiency was reported in patients who received abiraterone acetate in combination with a corticosteroid, following the interruption of daily steroids and/or with an infection or stress. Your doctor will monitor you for symptoms and signs of adrenocortical insufficiency, particularly if patients are withdrawn from corticosteroids, have corticosteroid dose reductions, or experience unusual stress. Adrenocortical insufficiency symptoms and signs may be masked by adverse reactions associated with mineralocorticoid excess seen in patients treated with YONSA.

Hepatotoxicity (Severe liver problems)

In postmarketing experience, there have been abiraterone acetate-associated severe hepatic toxicity, including acute liver failure, fulminant hepatitis, and deaths.

In two randomized clinical trials, grade 3 or 4 ALT or AST increases were reported in 4% of patients who received abiraterone acetate (during the first 3 months) after starting treatment. Patients whose baseline ALT or AST increased were more likely to experience liver test elevation than those with normal baseline ALT OR AST values.

Increased risk of Fractures and Death in Combination with Radium Ra 223 Dichloride

YONSA with methylprednisolone is not recommended for use in combination with radium Ra 223 dichloride outside of clinical trials. In a study, increased incidences of fractures and deaths have been observed in patients who received abiraterone acetate and a corticosteroid in combination with radium Ra 223 dichloride compared to patients who received a placebo in combination with abiraterone acetate and a corticosteroid.

Embryo-Fetal Toxicity

It is not known if YONSA is safe to use not in pregnant females but, based on animal reproductive studies abiraterone acetate can cause fetal harm when administered to a pregnant female.

Hypoglycemia (Severe low blood sugar)

Severe hypoglycemia has been reported when abiraterone acetate was administered to patients with pre-existing diabetes receiving medications containing thiazolidinediones, pioglitazone, or repaglinide. Your doctor will monitor your blood glucose levels if you have diabetes during and after discontinuation of treatment with abiraterone acetate.

Drug Interactions:

Avoid concomitant strong CYP3A4 inducers (e.g., phenytoin, rifabutin, carbamazepine, rifampin rifapentine, phenobarbital) during the YONSA treatment.