2016 studies highlight adjuvant zoster vaccine, UV protection

Key topics from mainstream medical literature that dermatologists may have missed in 2016 range from ophthalmology screenings to automotive windshields, an expert says at the 75th American Academy of Dermatology Annual Meeting, Orlando, Fla.

"Various studies have shown that whatever country you're in, skin cancer rates are higher" on the facial side typically exposed to the driver’s side car window, says Matthew Lee Palmer, M.D., a dermatologist at Geisinger Health System in Danville, Penn.

"The assumption is that from driving automobiles, there's enough UV exposure that we're increasing the risk for skin cancer, on the left side in the United States, or right side in Australia and Europe," he says.

In a recent study, investigators evaluated windshield UV protection versus that of side windows in 29 cars from 15 manufacturers, ranging from a 1990 Buick to a 2014 Tesla.

"It turns out that pretty uniformly, due to the requirements for shatterproof windshield glass, windshields do a very good job in protecting drivers from around 96% of UV radiation (range: 95% to 98%)." Conversely, single-pane side windows block only an average of 71% of UV (range: 44% to 96%).¹ Investigators write, "The difference between these average percentages is 25% (95% CI, 21%-30% [P < .001])." And only 4 cars (13.8%) offered more than 90% UVA blockage.

Dr. Palmer adds, "These researchers also found that the factory window tint that people think is protective does not block UVA, which is carcinogenic. And maybe more importantly, in dermatology, we have a variety of UVA-sensitive dermatoses such as lupus." Dermatologists must educate all patients that they still need sunscreens, Dr. Palmer says.

In herpes zoster, a phase 3 study confirms that the herpes zoster subunit vaccine containing recombinant varicella-zoster virus glycoprotein E and the AS01_B adjuvant (HZ/su, GSK) works as well in patients aged 70 years and older as it did in a previously published study of patients 50 and older.²

Dr. Palmer says, "The existing live attenuated vaccine (Oka-VZV; Zostavax, Merck), has shown mixed efficacy in patients greater than 70 years of age. Its efficacy is about 37.6%."

The new adjuvant vaccine provides 89.8% efficacy against herpes zoster (90.0% in participants 70 to 79 years old; 89.1% in participants 80 years and older). In pooled analysis of data from participants 70 or older in the current and previous studies was 91.3% (95% CI: 86.8 to 94.5; P <0.0001). Vaccine efficacy against postherpetic neuralgia was 88.8%.

The adjuvant vaccine's manufacturer submitted phase 3 results to the FDA in October 2016, Dr. Palmer says.

"I spoke to GSK, but they have no comment as far as pricing. The new adjuvant vaccine will be a big change for us," he adds.

In eye care, the American Academy of Ophthalmology (AAO) has updated its 2011 dosing recommendations for toxicity screening in users of hydroxychloroquine or chloroquine. Dr. Palmer says, "The AAO recommends dosing based on actual, not ideal, body weight,³ which is a big change from 2011."

The updated recommendations also state that major risk factors for toxicity-induced retinopathy include renal disease and use of tamoxifen, which confers a five-fold risk. Additional risk factors include pre-existing retinal or macular disease. However, factors found to pose less risk than experts previously believed include a history of liver disease, as well as increasing age.

Patients' risk of toxicity depends on daily dose and duration of use. "At recommended doses," guideline authors write, "the risk of toxicity up to five years is under 1%, and up to 10 years is under 2%, but it rises to almost 20% after 20 years. However, even after 20 years, a patient without toxicity has only a 4% risk of converting in the subsequent year," he says.

Outside of the dosing change, Dr. Palmer says, "AAO screening recommendations have stayed pretty similar: a baseline fundus exam within one year of beginning hydroxychloroquine or chloroquine; then, in patients without risk factors, annual exams can be deferred for five years. After that, annual exams should be performed."

Disclosures: Dr. Palmer reports no relevant financial interests.