Navigating neurotoxins’ differences

We now have three neurotoxins in our marketplace. Do you feel that these neurotoxins differ, and if so, how?

Amy Taub, M.D., dermatologist, Chicago: I use all three. I definitely think they're different. I don't know that I can explain why. I primarily use Botox (onabotulinumtoxinA, Allergan), but I think it's somewhat out of habit. I've done it for so long that I feel like it’s my violin that I just know how to play really well.

I do use Dysport (abobotulinumtoxinA, Medicis) around the eyes because it does give you a little bit more spread and a little more freeze. And there I think it’s OK unless somebody has really large orbicularis or ocular muscle inferiorly, because if it’s really frozen then sometimes that’ll become more prominent. But I don’t like it in the forehead.

If the Botox stops working as long for a patient, I'll use Dysport. I’ve had some people who’ve done well with Dysport and I’ve had some people who didn’t do well with Botox or Dysport, and so we used Xeomin (incobotulinumtoxinA, Merz) and we were successful with that. So there’s probably some immunological reaction to the proteins, is my thought.

Michael Persky, M.D., plastic surgeon, Los Angeles: I’m thankful for all three products that are currently available in the U.S. and I have used all three. I have the most experience with Botox because that was the first one we used. I use Dysport, based on the study that Dr. Corey Maas did, for the crow’s feet area, because his study showed a little bit of a better and longer-lasting effect on side-by-side comparison versus Botox. I do like all of the available neurotoxins. Again, I don’t think it’s the product per se, rather it’s how the injector uses the product on the patient’s face. With Xeomin my experience has been that maybe it takes a little bit more than the 1-to-1 unit dose that they recommend.

There’s big talk about the ratio of Dysport to Botox: 1-to-2.5 or 1-to-3. Again, I don’t put a lot of stock in that. I think the more you use the product, you get a feel for how it works in your individual patients. The ratio may be different in some patients. I don’t believe that there’s an exact number ratio for everyone. If there’s any neuromodulator market companies out there that want to dominate the market make a neurotoxin that is a little less expensive than the others - one product that's maybe $100 or $150 per vial less than the others will dominate all of the market if it’s equivalent to the products we have now. 

Ben Bassichis, M.D., plastic surgeon, Dallas: Well I use all three in my practice. I personally don’t see much difference, but one of the things that I do is when patients come in, if they’re happy with one product we keep them on that product. If it’s a new patient we talk to them about the three options and then we say, “Look, we can come up with a plan. We can try all three during the first year. And then we can decide which one you like better.” So it’s a very good way with an entry-level product into the aesthetic world to get the patient to be interactive with our practice.

It gets them in three times. It gives us the opportunity to teach the patient what to look for with these products, and then sometimes they come in and they notice subtle differences and at the end of the year they have a favorite. And we feel that that helps engrain the patients in our practice.

Every once in a while we'll do one and whichever one I have a little bit more of we might discount. But usually they’re all the same price.

Welf Prager, M.D., dermatologist, Hamburg, Germany: I’ve done quite a few of the studies comparing different neurotoxin products: Botox, Dysport and Xeomin. And when we looked at the results Xeomin to Botox, they are exactly exchangeable in the 1-to-1 ratio and two products compared to Dysport is probably 1-to-2.5 or a 1-to-3 ratio which would apply on the patients.

In Germany the patients do not ask which product we are using. That’s why I also exchange the products in my patients. The patients don’t notice any difference and I don’t notice any difference in coming back. There was the study where 21 doctors in Germany filled out questionnaires and there was no difference in the use these three different products.

Derek Jones, M.D., dermatologist, Los Angeles: Excellent question. I’m a data-driven, evidence-based kind of guy. Let’s talk just quickly about the three toxins and the data behind them. I think that you can - in most cases - use all three products interchangeably. Dysport I think would be the most different of all three in terms of the dosage required. As you require more units, there does tend to be more spread of effect. So patients and physicians will talk about the sort of stronger freeze that you get with Dysport particularly if you’re using it in the crow’s feet or in the frontalis.

I think it defuses a bit more and patients will note this sort of more global freeze if you will. That doesn’t mean it’s a bad product. Sometimes that’s what you want. So I think that’s one difference.

Now when it comes to Xeomin and Botox Cosmetic, I think that there is enough in the literature right now to suggest that they are pretty equivalent in their clinical response. If you look at the really nice paper by Sattler, Carruthers and Flynn, (Sattler G, Callander MJ, Grablowitz D, et al. Dermatol Surg. 2010;36(Suppl 4):2146-2154) in 24 units in the glabella, the efficacy curves and the extinction curves are laying right on top of each other.

There’s been a lot of argument that this is a 24-unit and not a 20-unit on-label study. So this has been going back and forth now for a couple of years. I think it’s highly likely that we’ll see a 20-unit glabella study Xeomin versus Botox within the next couple of years.

There is this sort of persistent signal out there among users that Xeomin’s maybe a bit softer. Whether that’s true or not I honestly do not know. I think we need better studies to sort of pick that up. At this point I agree with the other panelists. I’ve been in practice in L.A. since ’97. I have lots of retention in my practice. If the patient is happy with what I’m giving them, that’s what I use. With Botox Cosmetic, I have so much experience using multiple dilutions throughout all sorts of areas on the face that I just stick with what I know.

Michael Kane, M.D., plastic surgeon, New York: Yeah I carry and use all three toxins that are on the market. And rather than just talk about these, let’s talk about the future. You know in a year we’ll probably have four toxins and in a couple of years we’ll probably have five or six. We may even have a topical toxin. The same thing with fillers.

We’re going to have a lot of different fillers besides injectable fillers. We may have solid state HA (hyaluronic acid) threads that you can thread through the skin. I think as we get a bunch of different HA fillers we will see that they are more and more disparate.

We’ll have very soft fillers, very stiff, very thick fillers and they’re easily differentiated once you inject one person with them. But I think when you look at all the toxins, even when we have seven or eight we will start to realize how similar they are - not identical, not exactly the same, but they will be very similar. And the reason is dissociation - physiologic pH, the complexing proteins fall away.

There’s even evidence that suggests in the Eisele paper (Eisele KH, Fink K, Vey M, Taylor HV. Toxicon. 2011;57(4):555-565) that as soon as you reconstitute these toxins, a great deal if not total dissociation happens right in the vial. This is a bit controversial due to the amount of centrifugation that the specimens were put through. But most agree, at a physiologic pH, dissociation happens quickly.

That’s a little controversial, but I think as you get ease of use with all the different toxins you'll realize how close they are - not identical but very similar.

And, I’m going to be an outlier on this panel. I want the expensive, premium products. If you think that we're immune to market forces and the companies will drop the price and you won’t be dropping yours, you are mistaken. I like premium products and my patients do too. I would love to see a differentiated injectable toxin product. Actually there are some animal studies that show that one of the injectable toxins in development right now may last for a bit longer than the others.

Again, that’s a very, very early thing. But, again, if something like that were to come to market even with a premium price I think that would be outstanding.

Susan Weinkle, M.D., dermatologist, Bradenton, Fla.: I have all the products in my office, as well. I think that initially when we started using Xeomin, we did not understand the importance of the swirl. So when I started using Xeomin, some of the patients in my practice didn’t think it was as good, and did not think it lasted as long. Unfortunately, we were not inverting the bottle to make sure that we were getting all of the product off that rubber stopper and in the cap.

I think we probably were leaving a lot of units in the bottle, not understanding that part of the reconstitution of this product.

Once we started doing that (swirl), I have found all three to be very comparable. Patients often come into my office asking for specific products, so I think that we have to be on the cutting edge and have those things available.

I think that I’ve used less units, regardless of which product it is, in many locations. I used to use a lot of neurotoxin in the forehead and now I use very little neurotoxin in the forehead, especially in my older patients that need that frontalis. So I do believe we’ve learned that the products are probably more similar than they are different. I’ve learned to feather whichever product I am using more than I used to. I use a microdroplet technique in areas that I never used to - even periorbitally around the eye. I think that less is better than we used to think.

It’s an evolution that we’re going through with understanding products; with understanding how we use these products.

One thing I do like in my office is constitute the products in terms of its volume. So 0.4 in a syringe of one product, I can use interchangeably. So whether they put down Dysport, Xeomin, or Botox, I know I can utilize that volume the same and I don’t have to worry that we’ve mixed up something and I don’t know what it is.

I think the price point going forward is going to be a further discussion in terms of where we’re going to end up.