Hi everyone - hope you are well. Thought I’d cover a commonly asked about thing today for the severe asthmatics! I KNOW this infomercial will be a long one so let’s get started! 😂
WHAT IS A MAB?
First thing to note it that the words biologics/biologicals and mAbs are used interchangeably 😂. They are referring to the same thing! Here’s a quick explanation behind the names!; Biological drugs are sometimes referred to as biologic response modifiers (BRMs) because they change the manner of operation of natural biologic intracellular and cellular actions. Monoclonal Antibodies (mAbs) are are created to specifically target specific cells/parts of cells and to modify disease processes. In asthma, they are designed to target parts of the process that causes the immune system to turn against itself and attack the body when it shouldn't! The drug names all helpfully end in -mab too 😉. There are hundreds of different types that do different things but at the moment there are 4(.5) available in the uk for asthma that I’ll go into later 😉. Unfortunately there is nothing yet available for our non-allergic, non-eosinophilic brethren so hugs to all of you who are severe and unable to access mAbs at this moment in time... hopefully one day soon!
WHO CAN GET BIOLOGICS?
Each MAB has its own specific criteria, but in essence it’s; not smoking, having a ‘count’ high enough for the specific bio you want, a recent history of exacerbations, or long term steroid use and are on maximum optimal therapy available without the bio. If you are on a biologic you are classed as having severe asthma. In England, they can only be prescribed by a tertiary ‘asthma specialist’ hospital, however I think in Wales and Scotland things may be different 🤷♀️ (let me know below!). The other thing to note is that in Scotland some of them aren’t available and others require lower scores. Just a note (as not ALL doctors are aware), steroids can falsely lower BOTH IgE and eosinophil count. They are there being produced etc, but are masked. So if you had a low count whilst on 20mg+ steroids that may be the reason why, so it’s worth reasoning for when your steroid dose is lower. And yes this does lead to a catch 22 in some people - need a mAb cause you’re poorly but too poorly to come off pred to show you need the mAb! If you’re recommended for a mAb, it is not a 1 person decision. In England (again Scotland and Wales may be different, I don’t know so please comment below of it is!), they will take your case to a MDT (multidisciplinary team meeting) for discussion and then need to get funding approval. It may take up to a month to get your first dose once a spec doc is certain you should get it.
ALLERGIC/ATOPIC ASTHMA
This can be caused by having a high IgE. IgE stands for immunoglobulin E which a type of antibody. Antibodies are made by the immune system to protect the body from bacteria, viruses, and allergens. IgE antibodies are normally found in small amounts in the blood, but higher amounts can be a sign that the body overreacts to allergens. This can lead to an allergic reaction. People with a high IgE typically have allergic asthma (but not everyone with allergic asthma necessarily has it IgE driven).
OMALIZUMAB/XOLAIR
Xolair blocks the action of IgE which then hopefully causes less allergic reactions. A score over 30 can be classed as high enough for xolair, however if your score is too high (over 700 - weight dependant in adults, over 1300 in kids again weight dependent), it can also make you ineligible. If you want see the specifics google image ‘xolair chart’ and make sure you check out the 12+ age group one 😉😂. They will work out dose/eligibility using your HIGHEST IgE count in the last 6 months.
Depending on weight:levels ratio this can be either fortnightly or monthly, and the dose also changes. This is a subcutaneous injection(s), meaning it gets injected to just under the skin. Depending on the dose required, you may have up to 3 (I think) injections each time. It is licensed for patients from the age of 6 on 4+ steroid doses a year, on max therapy. Xolair also treats chronic idiopathic urticaria, obviously with different criteria 😅. However for the Scots among us, this is one you can’t access for asthma (however you can for urticaria)
EOSINOPHILIC ASTHMA
Eosinophils are a type of white blood cell, which are made in bone marrow. They can do many things like help fight bacteria and parasites and kill dying cells but in asthma it’s more concerning that they participate in allergic reactions, play a part in inflammatory responses and “respond” to areas of inflammation. If you have too many eosinophils (ie produce a lot all the time) they can ‘attack’ your lungs causing asthma which is not allergic. According to asthma UK about 40% of severe asthmatics have eosinophilic asthma.
MEPOLIZUMAB/NUCALA
In England this is typically the first eos mAb you’ll be put on. Mepo works by blocking interleukin-5 (IL-5) which is responsible for the maturation and release of eosinophils in the bone marrow. This means your body doesn’t produce eosinophils, and thus they can’t attack your lungs 😉. To be eligible for this drug you need to be over 12, have a blood count of 0.3 in the prev 12 months, be on max home therapy AND had either 4 pred courses in 12 months OR been on 5+mg/day of pred for 6 months. In Scotland you only need a count of 0.15 tho the other requirements are the same. This is a 4 weekly subcutaneous injection, and it is only 1 injection as it’s the same dose for all!
RESLIZUMAB/CINQAERO
For resliz you need to be over 18, have an eos count of 0.4 and have 3+ exacerbations needing steroids/increased steroids in the last year. Like xolair this is not available in Scotland. Resliz also binds on to IL-5 like mepo to prevent eosinophil production. It is given once every 4 weeks via IV infusion over 20-50 minutes, dose depending on weight.
BENRALIZUMAB/FASENRA
Whilst mepo and resliz work by preventing eosinophil production, benra works by attaching onto the eosinophil and destroying it. It cannot differentiate between eosinophils and basophils (another type of white blood cell) so attaches to both. Benra is licensed for adults on max therapy, with an eos count of 0.3 and had 4 or more exacerbations steroids in the last year OR 5+mg/day pred for 6 months, OR an eos count of 0.4 with 3 flares in 12 months that needed steroids. In Scotland the requirement is 0.15 and 4+ flares needing steroids OR 6 months of 5+mg/day steroids. It is a subcutaneous injection, for the first 3 weeks 4 weekly, then after that 8 weekly.
COMING SOON - DUPILUMAB/DUPIXENT
Still undergoing NICE approval for the treatment of asthma, so is only available in some areas in England (maybe UK??) under the early access program. It works by inhibiting interleukin-4 and interleukin-13 signalling. IL-4 and IL-13 together play a part on activating eosinophils and IgE, and should help decrease the type 2 inflammation in the lungs that appears in atopic and eosinophilic asthma. It is currently licensed in the uk for moderate-severe atopic dermatitis (eczema). It is a fortnightly subcutaneous injection, with the initial dose being double the maintenance dose (so the first dose consists for 2 injections). So far there’s been no eligibility provided for this drug in the UK for asthma, but their marketing says it’s for ages 12+ on max therapy, with both raised eos and raised IgE.
COMMON SIDE EFFECTS
The asthma mAbs tend to all give similar side effects so I thought I’d lump them all together here. Some are more likely than others in general, or more prevalent in a particular mAb. This is not a comprehensive list in any way, but covers the most common and/or the most important to be aware of even if unlikely!
Injection site pain, redness, small bruise/hive, stinging/burning sensation
Headaches/migraines, muscles aches and weakness, fever, abdominal pain, back pain, dizziness, drowsiness, fatigue,
Increased risk of infection (usually helminth injections)
Eczema, nasal congestion
Hypersensitivity reactions (anaphylaxis, angiodema, urticaria) - anaphylactic is is rare but common enough for the observation being needed for the first few doses (this is why you’re normally told to hang about for up to 3hrs post stab, and warned that it may happen. Some mabs have a higher likelihood than others. All mabs have a different waiting time. Those on self-administration should be aware of this).
WHAT IF I’M ILL?
If you are unwell when your injection is due contact your team before you attend. Some mAbs (and some clinics) do not recommend giving the injection of an active infection is going on, and so they may reschedule. Better to get confirmation of this BEFORE you make the effort to go in 😉😅. If it’s rescheduled don’t worry, they’ll get you in as soon as they can and then get you back on track. If it isn’t rescheduled don’t worry 😉, it just means the team are confident that it’s ok with the bio you are on!
STAYING ON YOUR MAB
Most (if not all) the mAbs have a 12 month check in and reassessment. Here they will assess basically how much the drug is working, and to make sure it’s cost effective. Normally to measure this they will look at if you’ve managed to come off/stay off/lower (to AI level only) steroids successfully. HOWEVER, if you can prove cost effectiveness a different way they should take that into consideration. So if you were constantly in and out of hospital, but now can manage at home with steroids, that shows that it’s saving them money that way. If you can show how admissions have reduced, become more spaced out, been triggered by things not treated by the bio you’re on or been shorter with less drugs to get you to a better place then they should listen. Also discuss how much it’s affected your QoL. Steroids is an easy baseline for them to aim for, but for some that’s an unrealistic aim, so show them other ways that it is helping that they can measure! If it’s not working for you, the doc may discuss switching you to an alternate bio to see if that helps more!
Hope this helps anyone who is in the process of getting on to a bio. And as I said, our Scottish and Welsh buddies please let me know if anything is different where you are!
Hopefully soon I’ll do a post about the common (and not so common 😉) asthma add ons, and maybe another about comorbidity add ons (depends how long the add ons post gets 😳😂). Stay safe everyone