Calcitonin Gene-Related Peptide (CGRP) monoclonal antibodies

CGRP monoclonal antibodies

Calcitonin gene-related peptide antibodies (CGRP) monoclonal antibodies (mAbs) are a new type of treatment for migraine.

CGRP mAbs are the first preventive medicines specifically developed for the treatment of migraine. Prior to their development, the only preventive medicine for migraine were drugs that had been developed for other conditions but which had found to be useful in treating migraine.

They are therefore an important development in migraine treatment.

How they work

During a migraine attack the cerebral nerves and blood vessels release substances including CGRP. CGRP is known to be involved in the brain processes which cause pain during the attack.

The new drugs target CGRP to prevent migraine developing. Research has found that these medications are safe and effective in reducing the frequency and severity of migraine attacks. They also have fewer side effects than other preventive migraine medication, the main side effects being soreness from them being injected and constipation which some people experience.

All of the medicines are taken by injection, either monthly or every few months. They are administered by an injection under the skin – known as a subcutaneous injection. You can do this yourself after being shown by a doctor or nurse. One of the medicines, Eptinezumab, is given intravenously (into a vein by infusion) once every three months.

Several of these drugs are now available on the NHS in the UK. Some vary in how they are are taken and who can be prescribed them.

Click on the titles below to see where they are are available and how they’re administered.

Side effects

CGRP mAbs are a safe and effective preventive treatments for migraine. However, as with any medication there are side effects and other things to consider before starting them.

They are still relatively new treatments, and we are learning more about them all the time. They are considered to be well tolerated. The most common side effects reported from the clinical trials were mild injection-site reactions (such as pain, swelling and skin reactions), constipation, itching and cramps/ muscle spasms.

If you’re concerned about side effects, you should speak to your specialist or headache nurse.

Monitoring

Continuous monitoring is required with all new treatments to ensure their ongoing safety and effectiveness in the long term. Staying in touch with your prescribing clinic or specialist and reporting any adverse effects is important.

Keeping a headache diary to monitor any side effects or reactions to CGRP mAbs also helps to monitor how you do on the treatment and that any changes can be made in a timely manner.

Pregnancy and breastfeeding

The clinical trials did not include treatment during pregnancy, and this is another area that gets carefully reported, when they occur. Of the recent reports on pregnancies during CGRP treatment (85 people), there were a few cases of toxicity, spontaneous abortions, and prematurity. While these also occur in the general population, it has meant that extra caution is advised to avoid their use in pregnancy and breastfeeding, to minimise the safety risks.

You can read more about migraine treatments and breastfeeding here.

Getting these medicines

CGRP mAbs are only currently being prescribed by headache specialists or consultant neurologists. If you are struggling to manage your migraine and think you may benefit from this or another treatment, you should see your GP for a review and possible referral to a headache specialist or consultant neurologist for treatment.

If you are having difficulties accessing these treatments, even though you’re eligible, you should speak to your specialist and PALS at the hospital.