Phase 3 Trial Data Highlights Efficacy of OnabotulinutoxinA in Platysma Prominence

Last week, Allergan Aesthetics announced positive topline results from the second of its phase 3 studies exploring the use of onabotulinumtoxinA (BOTOX Cosmetic) in the indication of platysma prominence.

According to Allergan, results of the study were consistent with the first of the trials, of which results were shared in April of this year. Within this second study, all primary and secondary endpoints were met, including statistically significant platysma prominence improvement and patient-reported outcomes. Adverse events were generally mild in nature, and results support the efficacy of onabotulinumtoxin A in treating moderate to severe platysma prominence.

Data is expected to be included in a US Food and Drug Administration regulatory submission later this year.

Lead clinical investigator, Sachin Shridharani, MD, FACS, a board-certified plastic surgeon based in New York City, spoke with Dermatology Times® to discuss the promising results of the study.

Transcript

Sachin Shridharani, MD, FACS: Hi, my name is Sachin Shridharani. I'm a board-certified plastic surgeon based in New York City on Manhattan’s famed Fifth Avenue. The name of my practice is LUXURGERY; we’re the confluence of luxury and aesthetic surgery. I'm also an associate clinical professor of plastic surgery at Washington University St. Louis School of Medicine.

Dermatology Times: What is platysma prominence? What do you hear from patients about this issue, and what is the unmet need?

Shridharani: Platysma prominence is basically a condition where we see the platysma muscle, which is the muscle responsible for part of the lower lip depressor complex and also helping pull down on the lower portion of the face. It anchors from the mandible, from the inferior lower border of the mandibular bone as a veil, all the way down to the clavicle, or your collarbone. We have a right and a left hemi-platysma, and in the middle over time, it can start to spread and separate, and we start to see those bands and cords across someone's neck, which can be a little bit unsightly, concerning, and make the end neck look a little bit more aged or skeletonized. Platysma prominence is basically when we really start to see those bands and cords.

When I think about what platysma prominence means to individuals or of the unmet need, historically, there's been a lot of challenges in treating platysma prominence. It typically requires surgery. When we do a neck lift, for example, which is in conjunction sometimes with the facelift or isolated on itself, which is basically re-draping and pulling the neck up, we sometimes will divide the bands and cut them. We cut that muscle, which doesn't leave us with a lot of problems per se, or we also often suture or repair them in the midline, to help bring those central bands back together and put them back where they belong. Most of the mainstay therapies have sort of involved larger surgical-type procedures.

Dermatology Times: What is the current treatment landscape for platysma prominence? How do these study results tell us how onabotulinumtoxinA might be used in this indication?

Shridharani: As mentioned, historically, the treatments involve a more sizable surgical-type procedure. There are some less invasive, but still surgical-type procedures, that involve using different types of sutures to place underneath the skin and cut those actual muscle bands without having to do a major surgical procedure. But again, it is still surgery, and as someone who loves to use a scalpel, there's absolutely nothing wrong with having surgery when necessary. But if we can avoid a bigger procedure in exchange for less downtime, less complications associated with it, and still get a nice improvement, it's always great to have less involved and less invasive options. I think that's where there's been a really incredible opportunity for using botulinum toxin type A to be able to help relax those muscle bands.

Dermatology Times: What should those in the dermatology space be cognizant of as a result of this study, especially given that Allergan Aesthetics plans to include this data in a regulatory submission near the end of the year?

Shridharani: I think it's really exciting for our colleagues in the dermatology space, plastic surgery space, just in aesthetics in general, that we can use a tried, trusted molecule like BOTOX Cosmetic, for example,and botulinum toxin type A, to be able to help relax those muscle bands, and have good data to support that we're seeing less muscle prominence. For me, the science is everything, and so the fact that we're able to already use botulinum toxin type A, or BOTOX, for the forehead, the glabella, the crow's feet, and those muscle complexes, to now take this tried and trusted molecule, inject the neck area and be able to have safe, highly efficacious, low risk types of outcomes, definitely builds the confidence. I thinkhelping my colleagues know that this is on the horizon, with being able to guide them on dosage and timing, really, is something that's going to continue to make the industry evolve in a positive way.

I like to look at the face, or do a facial assessment. For me, the face isn't defined as the forehead to the mouth or the eyes down to the chin. It's the scalp all the way down to the clavicle; that's the full face, and people start to not look like themselves when the face is out of balance or proportion. A mid-face is too deficient, lips might be too full, hollows under the eyes are too great, someone's been overcompensated or overfilled in a jaw line. Those discrepancies tend to throw off the facial balance and facial harmony. What's often been an unmet need in anon-surgical capacity is the lower third of the face.

We've had incredible opportunity to rejuvenate the upper third with our neuromodulators in an on-label capacity. Certainly in the mid-face, we've seen tremendous progress with dermal fillers and mild modulation and what we can do with our various products, so that's been amazing. The lower third has been a bit of an unmet need: being able to permanently reduce fat with deoxycholic acid, that's exciting and was a nice breakthrough in treating this area a handful of years ago. But as it continues to evolve, we now have jawline indications with fillers; that also helps bring home rejuvenating the lower third, and now we also have the ability to likely use a toxin, in BOTOX, to be able to reduce the muscle prominence of the platysma, which I think again, is also going to build a lot of confidence in what we can do in a non-surgical capacity to rejuvenate the lower third of the face.

[Transcript has been edited for clarity.]