Briefing Note: azacitidine (Vidaza)

SMC did not accept azacitidine for the treatment of adult patients who are not eligible for haematopoietic stem cell transplantation (SCT) with intermediate-2 and high-risk myelodysplastic syndrome (MDS), chronic myelomonocytic leukaemia (CMML) or acute myeloid leukaemia (AML).

• MDS, CMML and AML are all conditions affecting the bone marrow which interfere with its ability to make healthy blood cells. MDS comprises a varied group of blood disorders characterised by a reduction in the number of blood cells, complications of infection and bleeding, and a risk of progressing to AML. AML is a form of cancer that affects early myeloid cells which are not mature and accumulate in the bone marrow, and interfere with the production of red blood cells, platelets and white blood cells. AML is the most common type of leukaemia affecting adults and its incidence increases after 40 years of age. CMML is a rare blood cancer that occurs in later life with age of onset being 70 years, and is characterised by high numbers of white blood cells called monocytes. Symptoms of these cancers can include weakness and fatigue from anaemia (lack of red blood cells), shortness of breath, persistent and regular infections, and bruising and bleeding.
• Treatment of these conditions is primarily chemotherapy which usually involves different drugs given in combination to destroy the cancerous cells and allow the bone marrow to work normally again (known as remission). In some situations, high-dose chemotherapy and a bone marrow or stem cell transplant may also be considered but this option is not suitable for all patients. The drug azacitidine is similar to a building block of the genetic material of cells that is used when new cells are formed. The result is a block in cell production, and a decrease in the growth of cancerous cells. Azacitidine is given daily as an injection under the skin for 7 days followed by a rest period of 21 days, making a 28-day treatment cycle. A minimum of six cycles of treatment is recommended, with treatment continued as long as the patient continues to benefit or until disease progression. Patients should receive drugs for nausea and vomiting.
• Treatment with azacitidine significantly increased overall survival by 9.5 months compared with standard care regimens in patients with previously untreated higher-risk MDS.
• Blood toxicities such as thrombocytopenia (low platelet count), neutropenia (abnormally low neutrophil count), anaemia (low red blood cell count), leucopenia (decrease in number of white blood cells) and febrile neutropenia (neutropenia accompanied by fever) were more frequently experienced with azacitidine than standard treatment, as were reactions at the site of injection.
• SMC did not accept azacitidine for use because the justification of the treatment’s cost in relation to its health benefits is not sufficient, and a number of weaknesses in the economic case submitted by the manufacturer meant that the drug was not value for money.