Prostate cancer still holds the leading position in terms of male mortality. Every year, more than a million cases of the disease are diagnosed worldwide. However, with the introduction of the new drug Xtandi, the mortality rate from prostate cancer has significantly decreased.
The active substance of the drug is a highly selective androgen receptor inhibitor. This increases the effectiveness of therapy and makes the treatment relatively safe for the patient. In the United States, the drug was registered in 2012, and in the UK it is allowed to use since May 2016.
The drug was developed taking into account the factors that determine the resistance of prostate cancer to therapy.
The problem with PCR is its slow progression. From the beginning of malignant malignancy of cells to the appearance of clinical signs of the disease, on average, it takes 15-20 years. According to doctors, in the early stages of the pathological process is almost asymptomatic. For this reason, men go to the doctor too late, when radical treatment is simply impossible and will not bring the proper result due to the spread of metastases to nearby lymph nodes, bone tissue.
One of the main methods of treatment of metastatic (disseminated) prostate cancer is the use of hormonal agents. When blocking the production of androgens and their specific receptors, a positive effect can be achieved in almost 90% of patients. But as a practice has shown, previously used drugs did not give a stable result, and after 2 — 3 years, the disease returned.
Patients whose progression of tumor development persists against the background of ongoing therapy are diagnosed with castration-resistant prostate cancer. At the same time, approximately every fifth patient has a pathology that is initially resistant to hormonal treatment.
The study of the pathogenesis of the disease and the reasons for the lack of effect from medication has allowed us to develop several fundamentally new drugs. The results of clinical studies have shown that blocking the intracellular production of androgens in the tumor and inhibiting the transmission of impulses from androgen receptors into the cancer cell leads to a significant improvement in the condition of patients.
Information about the manufacturer
Xtandi (Enzamide) is manufactured by the Dutch pharmaceutical Corporation Astellas, which was formed in 2005 as a result of the merger of two other companies (Yamaguchi and Fujisawa). Atlas specializes in clinical developments in the field of transplantation, the creation of medicines for the treatment of cancer, resistant infections.
Generic Xtandi is a synthetic non-steroidal antiandrogen prescribed for the treatment of certain types of prostate cancer in men. Usually, the drug is prescribed for resistance to standard methods, after chemotherapy.
Xtandi is available in the form of gelatin capsules filled with a solution of a yellowish shade of an oily consistency.
The main active substance is enzalutamide in a dosage of 0.04 g per capsule.
Enzalutamide is an antiandrogenic drug.
Androgen receptors (AR) belong to the group of steroid receptors. Binding to androgen triggers a series of sequential reactions to further transform the AR, which causes its subsequent interaction with specific proteins and DNA of the cell. AR is mainly found in the genitals, but it is also found in other tissues of the body.
Xtandi affects the basic elements of the pathogenesis of prostate cancer progression. The drug does not inhibit the production of androgen hormones, but rather prevents their binding to the receptor apparatus of cancer cells. Thus, during the application process, it is possible to achieve not only stopping the growth of the tumor, but also its regression.
Features of pharmacokinetics
As the treatment of insulated gradually accumulates in the body. Constant concentration is achieved after a month of regular intake and remains at this level. The half-life is up to 10 days. The maximum plasma content is noted after 1.5-2 hours. This indicator is not affected by food intake.
Almost 100% of the substance binds to plasma proteins, is metabolized in the liver to form therapeutically active compounds. About 70% of the drug is excreted through the kidneys, the rest - with feces (less than 1% unchanged).
According to clinical studies in which men over 75 years of age suffering from prostate cancer participated, there is no difference in pharmacokinetics and therapeutic activity (compared to younger men).
Description of the active substance
Enzalutamide was discovered and developed by C. Sawyers and M. Jung of the University of California. The mechanism of action of enzalutamide is due to several effects. Substance:
- Blocks the binding of androgen to a specific cell receptor.
- Prevents translocation ("transfer") of the androgen — receptor complex inside the cell nucleus.
- Blocks the binding of the complex to DNA, which prevents further expression of the defective gene.
To date, no cases of resistance to the action of enzalutamide have been detected. However, generic Xtandi belongs to the second-line drugs and are used in the absence of results from other therapies.
Indications for use
Generic Xtandi is prescribed to men for the treatment of metastatic and resistant to other types of hormonal treatment of prostate cancer.
Currently, the possibility of using enzalutamide for the treatment of certain forms of breast cancer is being studied. If the clinical trials are successful, this pathology may be included in the list of indications for a prescription.
Restrictions to receive
Absolute contraindications to the appointment of Xtandi, according to the instructions for use are:
- individual intolerance (including one of the auxiliary components — sorbitol);
- severe liver pathologies;
- under 18 years of age.
Be wary of Xtandi appoint patients with concomitant encephalopathy and kidney diseases.
Application and dosage features
The daily dosage of the drug is 4 capsules. They take regardless of food, but it is advisable to drink KoXtandi at the same time. In case of accidental omission, the drug should be taken as soon as possible.
Possible adverse reactions
Patients undergoing treatment of Xtandi sometimes worried about:
- undue fatigability;
- hot flashes, redness of the skin;
- digestive disorder;
- anxiety and anxiety;
- memory and attention disorders;
- the increase in the size of the breast;
- slight fluctuations in blood pressure.
Changes in the white blood cell formula, edema, excessive dryness of the skin, itching, and rash, as a result of an allergic reaction, are also possible.
Patients with severe kidney and liver damage were excluded from clinical trials. Therefore, the security of receiving generic Xtandi these categories of patients is unknown. Taking into account the features of pharmacokinetics, experts assume that easily occurring kidney pathologies do not require correction of the drug dose, but in liver diseases, the drug is prescribed with caution.
If there is a history of convulsive seizures and encephalopathies, the patient needs constant medical monitoring. If you have a long-lasting headache, coordination disorders, and some other neurological disorders, you need to do an MRI of the brain.
In patients who have suffered a stroke or traumatic brain injury, there is a risk of convulsions while taking Xtandi. With caution, the drug is used for severe diseases of the cardiovascular system.
Unknown selects whether unsaluted of the seminal fluid. However, men taking Xtandi are advised to use barrier methods of contraception.
How to distinguish a fake?
According to publicly available data, the situation with drug falsification in the global pharmaceutical market is catastrophic. Therefore, some people even try to bring the simplest drugs from abroad. This is especially true for serious medications for the treatment of cancer.
Turning to an intermediary for help in purchasing and delivering Xtandi from EU countries, it is recommended to ask to show cash documents confirming the purchase of the drug.
Possibility of interaction with other medicines
Caution should be observed when combined with:
- painkillers (narcotic and non-narcotic);
- antibacterial preparation;
- antitumor medications (due to the risk of neutropenia);
- anticonvulsant medications;
- neuroleptics, sleeping pills, and sedatives;
- blockers of β-adrenoreceptors, calcium channels;
- hormonal medications;
- cardiac glycoside;
- drugs intended for the treatment of HIV;
- some lipid-lowering drugs.
Given such a wide list, the doctor should be consulted about taking any medication.
Work with alcohol
Due to the toxic effect of enzalutamide on the liver, additional consumption of alcoholic beverages is not recommended.
Treatment is symptomatic, and the patient should be under medical supervision for at least a week, which is associated with a long half-life of the drug.
According to the information provided in the instructions, Xtandi is stored at room temperature.
The manufacturer admits the possibility of a safe reception of generic Xtandi within three years from the date of the issue stated on the carton box and blister with the capsules.
Conditions for discontinuation of therapy
The decision to end the course is made by the doctor.
Feedback from doctors
Dr. Richard Hirschman oncologist: "Specialists around the world are sounding the alarm, as the number of patients with prostate cancer is increasing every year. The number of cases of treatment-resistant forms of pathology is also increasing. Until recently, the treatment of such patients was not possible. However, with the advent of generic Xtandi on the global pharmaceutical market, it has become possible to provide effective and relatively safe therapy".
Feedback from patients
David, 52: "I always took care of my health, I do sports, I do not drink or smoke, so the diagnosed prostate cancer became a thunder in the middle of a clear sky. Naturally, I discussed with my doctor all the options, even those not used in UK. I was ready to sell everything I could and go to Israel. But the doctor convinced him to start medication therapy with the innovative drug Xtandi. As a result, after a few months, the doctor noted a decrease in the size of the tumor, and the side effects only occasionally worry headaches.