If you're considering BIMZELX (bimekizumab) for psoriasis and you’re either pregnant or breastfeeding—or even just planning to be—it’s natural to wonder: is it safe? I dove into the latest clinical guidelines, regulatory documents, and even a couple of patient forums to get a grip on what's truly known (and unknown) here. Below, I’ll break down the real-world considerations, pull in regulatory perspectives from different countries, and share my own firsthand experience navigating these questions as a clinical pharmacist.
BIMZELX (bimekizumab) is a relatively new biologic drug, approved for moderate to severe plaque psoriasis. It's an antibody that targets interleukin-17A and 17F, shrinking inflammation. While the results for skin clearance are impressive, what happens when it comes to pregnancy and breastfeeding is less clear.
When I first had a patient ask me, “Can I stay on BIMZELX if I want to get pregnant?” I realized how much gray area there is here. Most new biologics only have animal data, and the leap from mice to mothers is not always straightforward. So, what do the experts say?
Let’s start with the basics: what do official guidelines and prescribing information say in different countries? I’ll summarize below, then show a quick comparison table for international standards.
The FDA labeling for BIMZELX (source) states:
The European Medicines Agency echoes similar caution. Their Summary of Product Characteristics (SPC) notes:
The TGA’s Australian Product Information gives it a B1 pregnancy category, which means limited data in humans and no observed fetal harm in animals, but also recommends caution.
| Country/Region | Regulatory Agency | Pregnancy Category | Legal Basis | Breastfeeding Guidance |
|---|---|---|---|---|
| USA | FDA | Not assigned; see risk statement | 21 CFR 201.57 | Unknown; use caution |
| EU | EMA | Not assigned; contraindicated if not using contraception | Directive 2001/83/EC | Unknown; avoid if possible |
| Australia | TGA | B1 | Therapeutic Goods Act 1989 | Unknown; use caution |
In my practice, I’ve had two patients in their early 30s on BIMZELX who wanted to start a family. For both, the lack of human data was a big worry. We spent a lot of time scouring the literature, and even called the manufacturer’s medical information line (no extra insights, just “use only if necessary”).
One patient, “Maria”, chose to pause treatment six months before trying to conceive. Her dermatologist agreed, since the drug’s half-life is about 23 days, and it can take several months to fully clear. Maria’s psoriasis did worsen, but she felt reassured. Another patient, “Lana”, decided to continue until she had a positive pregnancy test, then stopped immediately. This was a bit nerve-wracking, and we had to monitor closely, but it worked out—healthy baby, no complications, but that’s a story, not a guarantee.
What struck me: the lack of hard data forces everyone—patients, doctors, pharmacists—to make judgment calls. The safest bet is always to avoid BIMZELX during pregnancy unless the benefits clearly outweigh the risks.
Dr. Michael Feldman, a dermatologist at a major teaching hospital, put it this way in a recent webinar (see discussion): “With new biologics like bimekizumab, we’re always a step behind on pregnancy data. The default is to err on the side of caution—but that can mean real suffering for some patients.”
He also pointed to the National Psoriasis Foundation's resource, which summarizes that no biologic (including BIMZELX) is proven safe in pregnancy, but some TNF blockers have a longer track record and may be preferred if treatment during pregnancy is unavoidable.
If you check actual patient forums—like this Inspire thread—you’ll mostly find people frustrated by the “no info” answer. Some report accidental exposure with no problems, others switched to older drugs with more safety data. But there’s no consensus, and most are told to stop the drug if planning pregnancy.
Here’s how I handle this in my own workflow as a pharmacist (with the patient’s consent):
I’ve definitely had patients get frustrated with the lack of answers—one even snapped, “So am I supposed to just guess?” In reality, that’s not far off. It’s about weighing risks and benefits, and making the call that feels right for that person’s life.
Let’s say Patient A is in Germany, and Patient B is in the US. Both want to get pregnant while on BIMZELX.
This regulatory gap can make cross-border patients (military families, expats, etc.) pretty anxious. In a 2022 forum post, a user shared how her US doctor was “okay with continuing until I got a positive test,” but her German insurance required written proof of discontinuation. That’s how much standards can differ.
At the end of the day, the answer is: nobody can say for sure that it’s safe. All major regulators urge caution, and the default advice is to avoid BIMZELX during pregnancy and breastfeeding unless there’s a strong reason to continue. Real-world experience says some patients do okay, but that’s not the same as proof.
If you’re in this situation, talk it through with your dermatologist and your OB/GYN. Consider the timing, your disease severity, and your comfort with risk. If you do get exposed to BIMZELX while pregnant, let your doctors know, and consider joining a pregnancy registry to help build the evidence for others.
As for me, I wish there were better answers—but until then, caution is the name of the game. If you want more detail, check the full FDA label here and the EU SPC here.
And if you’re reading this and feeling frustrated—so are most of us in healthcare. Here’s hoping more answers come soon.