CGRP therapies are a new type of medications used to prevent and treat migraine attacks.
The medication blocks a protein called calcitonin gene-related peptide (CGRP). CGRP may cause inflammation and pain in the nervous system of people who have migraine attacks.
CGRP migraine medications are also called anti-CGRP, CGRP inhibitor and CGRP antagonist treatment.
How CGRP is used to treat migraine
People with migraine may have more CGRP in their blood. This chemical has been studied for more than 25 years. It’s thought to be a significant factor in the sequence of events necessary to trigger a migraine attack.
CGRP may help cause migraine attacks. It also worsens headache pain and makes it last longer. CGRP migraine treatments work in one of two ways to stop or treat migraine pain:
- They block the sites in and around the brain where CRGP must attach to work. (Aimovig)
- They bind to CGRP and prevent it from working. (Emgality, Ajovy and others)
How CGRP treatment is taken
There are currently three medications available, and a number of others in development, to prevent migraine based on blocking CGRP.
Currently available in Australia:
In late stage development, not yet available in Australia:
- ubrogepant (Ubrelvy, available in the US)
- rimegepant (Nurtec, available in the US)
Aimovig, Ajovy and Emgality are taken by an injection with a needle or automatic pen. This is similar to how some people with diabetes take insulin.
Vyepti is a 30 minute infusion which you will need to go to a clinic to get every three months. The gepants under development are mostly tablets, zavegepant is being developed as a nasal spray.
How much does CGRP treatment cost?
In Australia, Aimovig is available on a private prescription between $750 and $850 a month. All free trials have ended. A discount program enables you to get 140mg (2 x 70mg pens) for $695. To do this you need to:
1. Email your prescription to aim[email protected]
2. Order and pay for your Aimovig at http://aimovig.phusionpayments.com.au/ including nominating which pharmacy you will collect from.
3. Take the hard copy of your prescription to your pharmacy for dispensing.
Novartis has decided to remove Aimovig from consideration for listing on the PBS. Read more.
Emgality was listed on the PBS from 1 June 2021. However, the vast majority of people will still only be able to access it via a private prescription.
You can get Emgality on a private prescription from either a neurologist or a GP. There are no restrictions or limitations for private prescriptions, so no minimum number of migraine days or drugs you need to try first. Your doctor will need to log on to the Lilly portal for doctors – https://mylilly.com.au/ – and print out a voucher for you to take to the pharmacist. Then the pharmacist will need to order it in for you (it generally won’t be in stock). The recommended retail price is $263 per month with the discount voucher. Without the discount voucher the price varies considerably but is around $600 a month.
From 1 June, those who meet the following criteria will be able to get Emgality on the PBS.
- You must have Chronic Migraine (15 headache days, 8 of which are migraine days) for at least three months.
- You must have failed three older medications like propanolol, topiramate and amitryptiline
- You must be managed for medication overuse headache
- You must be under the care of a neurologist
- Your neurologist must initiate treatment (your GP can do continuing scripts)
- You cannot get both Emgality and Botox on the PBS.
If you qualify for Emgality on the PBS you must achieve a 50% reduction in migraine frequency and severity to continue to get it on the PBS after the first 6 months. You will be charged the maximum PBS co-pay rate of $41.30 or $6.60 for those with a health care or pension card.
Ajovy was recommended in the March 2020 meeting of the PBAC to be listed on the PBS, but as yet the medication has not been listed. All parties tell us they remain committed to the process, but we have no estimated date for a listing. If you're unhappy about this, write to the Health Minister Greg Hunt and tell him so - ultimately it is his decision.
You can get Ajovy on a private prescription from either a neurologist or a GP. There is an access program for Ajovy called Momentum, and you can get signed up for this through your neurologist. This will allow you to purchase Ajovy for $284 per month instead of the normal rrp of $850 per month.
NOTE: Everyone on the Ajovy Momentum program will ger their June and July 2021 doses for free! You should receive an SMS to confirm, but talk to your pharmacy if you're not sure.
You can get access to this program from either your neurologist or GP, but it is very unlikely your GP will have the brochures with the information you need on how to order. Ask your doctor to call Teva Medical Information on 1800 288 382 and they should be able to send out the brochure that you need and assist them with any other questions they have.
When will these medications be available on the PBS?
There are three steps before a medication can be listed on the PBS, allowing us to get it for $41 or $6.60 with a concession card.
- It needs to be recommended by PBAC (the pharmaceutical benefits advisory committee – an independent body who decides what should be on the PBS or not)
- The drug company needs to negotiate price and restrictions with the Department of Health
- The listing needs be approved by the Minister for Health, and if it is over $20m a year, the full cabinet.
At this point, Emgality is the only one listed on the PBS. Ajovy is stalled at hurdle number 2, but we are assured things are progressing. Aimovig has been withdrawn from consideration for the PBS, although we remain committed to fighting for it. Vyepti has not yet applied but we understand will do so in late 2021 or early 2022.
While there are no restrictions on your GP or Neurologist prescribing the drug privately (that is, not through the PBS), the restrictions to get any that make it on to the PBS are for chronic migraine patients only, and likely to be similar to the current restrictions for accessing Botox. These are:
- You must have more than 15 headache days per month, 8 of which are migraine days;
- You must have failed three other medications to prevent migraine; and,
- You must maintain a 50% improvement to continue to get PBS subsidised medications.
Note: Lilly has also applied for treatment-resistant episodic patients (that is, people with less than 15 migraine days per month but enough that they need a preventative, who have also failed three other preventatives) to access Emgality on the PBS. This application was rejected.
WHAT ARE THE RISKS?
All the effects of CGRP migraine treatments are not yet known. There may be some long-term risks that can happen in some people.
The currently available CGRP migraine treatments have to be injected. This can cause pain. Additionally, an injection site on the skin can get infected. Washing your hands, cleaning the site, and using new needles each time is important. Additionally, we know:
- Aimovig causes allergic reactions, constipation, and high blood pressure
- Emgality can cause allergic reactions, which may cause difficulty breathing
- Ajovy can cause itchiness or a rash
Many have noticed that their migraine pattern and symptoms change once starting a CGRP treatment. There are many common symptoms which are believed not to be side effects of the drugs, but rather migraine symptoms that are more noticeable in the absence of a headache, such as fatigue and nausea.
Weight gain and loss have also been reported, some of which may be attributable to appetite and increased ability to exercise as a result of better management of migraine. Weight gain is more frequently noted with Emgality; weight loss with Ajovy; and Aimovig has fairly equal reports of gain, loss or no change.
Hormonal changes (particularly changes to periods), and hair loss, have also been noted anecdotally and may be due to the way CGRP interacts with hormones, but further research is required.
If you have anxiety or depression, as most people with migraine do, it is a good idea to work with your psychologist on adjusting your perspective when starting CGRP therapies. Because the response can be quite rapid, some people find their anxiety increased as they are still bracing for the next attack which doesn't come. Additionally, for many who had lost all hope of effective treatment, the anxiety of these new treatments possibly not working can be overwhelming. Give yourself permission to be well, and try not to over-think whether you are experiencing side effects or whether the medication is working or not.
You may also find that your triptan medications do not work as well as they used to. This is because the CGRP dilated the vessels in your brain, and the triptan would constrict them; with the CGRP being blocked the triptan doesn’t have as much impact.
CGRP plays a key role in dilating or widening your blood vessels. This helps to balance blood pressure. It is theorised that migraine medications that lower CGRP levels may cause side effects that affect your blood pressure and heart, but no research or clinical trial has recorded significant cardiovascular problems as yet. If you are on blood pressure or heart medications be sure to discuss this with your doctors before beginning CGRP treatment. Aimovig has recently added high blood pressure to its list of side effects.
CGRP is also involved in other body mechanisms. For example, it helps with wound healing and plays a role in some of the digestive organs. It’s not yet known if blocking this chemical protein could affect wound healing or trigger digestive disorders. Some people may be more prone to getting head colds.
All of the CGRP monoclonal antibodies have been designed to not impact on the immune system. They just use the immune system for delivery. Your immunity is not suppressed, and you are not more vulnerable to bacteria or viruses, including COVID-19.
Can I use CGRP therapies if I am pregnant?
Discuss the pros and cons with your doctor. There are some concerns as these medications are so new and CGRP plays an important role in pregnancy. The CGRP treatments were tested on monkeys in clinical trials with no adverse effects noted. For this reason, the TGA has classified these medications as Pregnancy Category B1. There have been no studies of CGRP treatments in human pregnancies, but some limited case reports (that is, a report of a single patient experience) of CGRP treatments used by women while they were in the first trimester have reported no significant issues. Read more about treatment options during pregnancy at the Association of Migraine Disorders.
What are the benefits?
CGRP migraine treatments may work for people who have debilitating and/or frequent migraine attacks.
A 2018 study found that almost a third of people tested had 50 percent fewer migraine attacks. Their migraine symptoms also lasted fewer days. In other research, a third of the people with migraine had up to 75 percent improvement. Similarly, Migraine Australia found in a survey of our members that 36% of people had a 75% reduction in frequency and severity. CGRP treatments have also proven to be effective for people who did not have success with other medications.
Some migraine medications stop working as well if they’re used for some time. Response to CGRP medications gets better with time for most people. In rare cases, some may develop resistant antibodies to the medication, and will need to switch to a different one. Migraine is a very big spectrum, caused by different genes and triggers. No one migraine medication works for everyone, but failing one CGRP mediation does not mean all of the CGRP medications will not work for you.
The injectable CGRP migraine treatments that are currently available are only needed once a month, or once every three months. This makes it easier to not miss a dose.
CGRP migraine treatment is a new type of treatment. It may work better for some people with migraine than other kinds of medications.
CGRP migraine treatments give people relief by preventing migraine attacks from happening, and by reducing the length and severity of attacks. Side effects are generally mild.
Like any medication, CGRP treatment may not be right for you. Talk to your doctor to find out; they may recommend trying it for a few months.
Keep a migraine diary before starting a CGRP medication and for the first few months of taking it so you can measure how well it works for you. Let your doctor know of all changes in symptoms and any side effects you may have.