Conference Coverage

Light-based technologies emerging as promising acne treatments



Optical treatments for acne are emerging as promising alternatives to conventional treatments, a development that inspires clinician researchers such as Fernanda H. Sakamoto, MD, PhD.

Dr. Fernanda H. Sakamoto, dermatologist, Wellman Center for Photomedicine at Massachusetts General Hospital, Boston

Dr. Fernanda H. Sakamoto

“I love treating acne, because it can have a huge impact on our patients’ lives,” Dr. Sakamoto, a dermatologist at the Wellman Center for Photomedicine at Massachusetts General Hospital, Boston, said during a virtual course on laser and aesthetic skin therapy. “Acne is the most common disease in dermatology, affecting about 80% of our patients. Eleven percent of these patients have difficult-to-treat acne, and it is also the No. 1 cause of depression and suicide among teenagers and young adults. And, even though there’s no strong evidence that optical treatments work better than conventional acne treatments, people still spend a lot on those treatments: more than 220 million in 2019.”

Early results from a pilot study suggest that use of a novel laser system known as Accure in patients with mild to moderate acne resulted in an 80% reduction in acne lesions at 12 weeks. The laser prototype, which uses a 1,726 nm wavelength and is being developed by researchers at the Wellman Center for Photomedicine, features a built-in thermal camera in the handpiece that allows the user to monitor the skin’s temperature during treatment.

In initial pilot studies of the device, Dr. Sakamoto and colleagues observed consistent damage of the sebaceous glands, with no damage to the epidermis, surrounding dermis, or other follicular structures. “But because the contrast of absorption of lipids and water is not very high, we needed to create a laser with features that we have never seen before,” she said. “One of them is a robust cooling system. The second prototype features a built-in thermal camera within the handpiece that allows us to see the temperature while we’re treating the patient. It also has built-in software that would shut down the laser if the temperature is too high. “This is the first laser with some safety features that will give the user direct feedback while treating the patient,” she said, noting that its “unique cooling system and real-time monitoring ... makes it different from any of the lasers we see on the market right now.”

Dr. Sakamoto and colleagues (Emil Tanghetti, MD, in San Diego, Roy Geronemus, MD, in New York, and Joel L. Cohen, MD, in Colorado) are conducting a clinical trial of the device, to evaluate whether Accure can selectively target sebaceous glands. As of Oct. 23, 2020, the study enrolled more than 50 patients, who are followed at 4, 8, 12, and 24 weeks post treatment, she said.

To date, 16 patients have completed the study, and the researchers have observed an average lesion reduction of 80% at 12 weeks post treatment, after four treatment sessions. This amounted to more than 12,000 trigger pulls of the device, with no unexpected adverse events. Average visual analogue scale pain scores immediately after treatment have been 1.09 out of 10.

Histologic assessment of skin samples collected from the study participants have revealed selective damage of the sebaceous glands with a normal epidermis and surrounding dermis. “Because this laser is near infrared, it is not absorbed by melanin, making it possible for a safe treatment in darker skin tones,” Dr. Sakamoto said during the meeting, which was sponsored by Harvard Medical School, Massachusetts General Hospital, and the Wellman Center for Photomedicine.

“We have shown that it is possible to create a selective laser for acne treatment at 1,726 nm. We have proven it mathematically as well as with histological samples,” she said. “Now we are moving on to a larger clinical trial for the FDA clearance.”

Another strategy being developed for acne treatment is to make nonselective lasers selective by adding gold microparticles into the hair follicle and sebaceous glands, to allow the lasers to be absorbed. In a study that used a free electron laser, Dr. Sakamoto and colleagues demonstrated that these microparticles can stay within the sebaceous glands for selective damage of the sebaceous glands. In a subsequent pilot clinical trial they showed that the addition of the gold microparticles followed by a diode laser treatment made it possible to reduce both inflammatory and noninflammatory lesions.

More recently, an open-label European study of acne treatment with light absorbing gold microparticles and optical pulses demonstrated that the treatment led to an 80%-90% reduction of inflammatory lesions at 12 weeks, with a reduction of Investigator’s Global Assessment scale from 2 to 4.

The Food and Drug Administration cleared the treatment, Sebacia Microparticles, for the treatment of mild to moderate acne in September of 2018, but according to Dr. Sakamoto, “the company has struggled, as they were only commercializing the device in California and Washington, DC.”

Photodynamic therapy (PDT) is also being studied as an acne treatment. “PDT uses a photosensitizer that needs to be activated by a light source,” she noted. “The combination of red light and aminolevulinic acid (ALA) or methyl ester ALA has been shown to damage the sebaceous glands”.

In a recent randomized controlled trial that compared PDT to adapalene gel plus oral doxycycline, PDT showed superiority. “Because PDT induces apoptosis of the sebaceous glands, it causes a lot of pain and side effects after treatment,” Dr. Sakamoto said. “However, it can clear 80%-90% of acne in 80%-90% of patients. But because of the side effects, PDT should be limited to those patients who cannot take conventional treatments.”

Dr. Sakamoto reported having received research funding and/or consulting fees from numerous device and pharmaceutical companies.

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