Azacitidine (Vidaza)
What is it, and how does it work?
Azacitidine (often shortened to ‘Aza’) is the common term used for this drug, and the name of its active ingredient. Vidaza is a trade name for the drug, which is sometimes used.
It has been widely available in the UK for the treatment of MDS since its approval by NICE in February 2011. (NICE is the the National Institute for Health and Clinical Excellence; even though a drug may be listed by the Medical and Health products Regulatory Agency – MHRA - as licensed in the UK, it still needs approval from NICE to be prescribed via the NHS). MDS UK campaigned alongside the haematology community to make Azacitidine available in the UK, and it has continued to be the main drug therapy used since in treating intermediate to high-risk MDS.
Azacitidine is a type of chemotherapy drug known as a "hypomethylating agent"
Hypomethylating agents are less intensive than other types of chemotherapy. The aim of hypomethylating agents is to slow the progression of the disease while at the same time producing as few side effects as possible, thereby having a gentler impact on quality of life. Although Azacitidine cannot cure MDS, and doesn’t work for everyone, it may ‘modify’ it and even reduce the frequency of blood transfusions. In some cases (mostly when treating high-risk patients) other drugs can be used in conjunction with Aza to make it more effective. Research into these drug combinations is ongoing, and the results are generally encouraging.
How does Azacitidine work?
Azacitidine works at the DNA level, by "switching on" particular genes that can stop cancer cells growing and dividing. This reduces the number of abnormal blood cells and helps to control cell growth.
How is it administered?
You have Azacitidine as an injection just under your skin (subcutaneously), given by a doctor or nurse. It is usually injected into the abdomen, though occasionally the thigh or buttock. In most cases you receive the injections as an outpatient, although there have been positive trials with home administration in a few regions. Appointments generally take around an hour – the Aza has to be kept cold-stored and is only taken out when you check in for your appointment, it then has to be as close as possible to body temperature to be comfortably administered which can take a little while (your nurse might ask you to hold the pouch between your hands while they prepare the injection site, to help warm it up!). You may also need a pre-chemotherapy appointment a few days before each cycle, which may also take about an hour, but this can sometimes be combined with a regular supportive care appointment, eg. when you will already be at the hospital for a blood transfusion or blood test.
Being a low-intensity therapy, it can take several cycles to show any marked results, generally at least six or seven. It is administered every consecutive day for 5 - 7 days (there can be a degree of flexibility over this; for example you may opt to have it for 2 or 3 days either side of a weekend, to give you a break). You then have 21 days off before the next cycle. As long as it is not causing any major side-effects, you can continue having Aza for as long as it keeps working for you.
What are the more common side effects?
Frequently-reported side effects from Azacitidine include:
- mild nausea - can be alleviated with anti-sickness tablets,
- constipation - often due to a sensitivity to certain anti-sickness tablets, in which case an alternative tablet can be prescribed.
- soreness and/or itching around the injection site: applying Evening Primrose oil or St John’s Wort oil directly to the site can help, both of which are readily available in supermarkets and High Street stores (if in capsule form, simply snip the end off and tip the oil into your hand to apply).
- Some patients have reported a mild headache or feeling sleepy a few hours after their Aza injection, so try to make sure you can rest up and have a nap if you need one.
A word about infection
As with any chemotherapy, your immune system is likely to be suppressed and under additional strain, so you should take extra care to avoid bugs and viruses during the treatment week and for a few days afterwards. Ask your clinician or Clinical Nurse about the risk of infection, and whether you need a neutropenic pathway. This could be a card or form which gets you priority access for hospital admission and treatment, should you show signs of fever or develop flu-type symptoms. Neutropenic sepsis is a major risk for anyone whose neutrophils (a type of white blood cell) are lowered by chemotherapy treatment, as your body needs neutrophils to fight infection. In a healthy person our immune systems are constantly fighting off different ‘invaders’ in the form of bacterial, viral and fungal infections, but someone who is neutropenic and contracts an infection could need extra help – possibly intravenous antibiotics – to recover quickly.
At the first signs of a raised temperature or fever it’s best to get advice as soon as possible - stating you have a neutropenic pathway will help move things along quickly.
Professor Paresh Vyas talks to MDS UK Support about Azacitidine
Below is recording of Professor Vyas from Oxford Teaching Hospitals speaking about Azacitidine at a recent MDS UK support meeting. We are very grateful to Professor Vyas and CNS Claudia Costa for taking time out from their very busy work schedules to speak to us.
