Briefing Note: abiraterone (Zytiga) Resubmission
SMC accepted abiraterone acetate for restricted use with prednisone or prednisolone for the treatment of metastatic castration resistant prostate cancer (mCRPC) in adult men whose disease has progressed on or after a docetaxel-based chemotherapy regimen. Abiraterone is restricted for use in patients who have received only one prior chemotherapy regimen.
- Prostate cancer is a disease where cancer develops in the prostate, a gland in the male reproductive system. Most prostate cancers grow very slowly and men may not experience symptoms for many years. Symptoms can include difficulty in passing urine, passing urine more frequently and pain when passing urine. The hormone testosterone helps cancer cells in the prostate to multiply and spread. When it has spread to another part of the body, it is called metastatic prostate cancer.
- Prostate cancer can be treated by reducing the available testosterone by medical or surgical means. However, treatment may stop working after a time and the cancer resumes growth despite hormone therapy. This is known as ‘hormone refractory’ or ‘castration resistant’ prostate cancer. Abiraterone acetate is a medicine used in men with mCRPC. It works by decreasing the level of circulating testosterone, and is given as four tablets in a single daily dose which must not be taken with food.
- A study has shown that abiraterone plus prednisone significantly improved overall survival by nearly 4 months in individual patients compared with placebo (a dummy medicine containing no active treatment) plus prednisone in patients with mCRPC previously treated with docetaxel.
- In studies, side effects experienced by a greater proportion of patients given abiraterone than those given placebo included low levels of potassium, high blood pressure, fluid retention and heart disorders.
- This SMC advice takes account of the benefits of a patient access scheme1 (PAS). A PAS is a scheme proposed by a manufacturer in order to improve the cost effectiveness of a medicine and thus enable patients to receive access to new medicines that may otherwise not have been judged to be a cost-effective use of NHS resources. The proposed PAS gives a discount on the price of the medicine.
- SMC accepted abiraterone for restricted use in NHSScotland because the expected benefits of the medicine outweighed its cost when considered in the context of the PAS and the decision modifiers that allow SMC to take account of additional factors such as improvement in life expectancy, quality of life, and evidence of benefits in specific patient subgroups. This SMC advice depends on the continuing availability of the PAS in Scotland.
In March 2009, it was announced that an agreed national framework would be introduced to allow the operation of PAS in NHSScotland. A patient access scheme assessment group (PASAG) was established to review and advise NHSScotland on the feasibility of proposed schemes for implementation. PASAG operates separately from SMC in order to maintain the integrity and independence of the assessment process of SMC.