When topical treatments fail, phototherapy offers potential for improvement

10.01.2019

by Andrew D. Bowser
Contributing Writer, MedPage Today

Phototherapy, a strategy used to treat skin disease for thousands of years, remains an effective and relatively safe option for many psoriasis patients today, according to the co-chair of a working group that has developed new, comprehensive guidelines for using light wave therapies in this skin disease.

“I think that in people with moderate to severe psoriasis, [phototherapy] provides a nice alternative to systemic therapy,” said Craig A Elmets, MD, a co-author on the joint American Academy of Dermatology (AAD)/National Psoriasis Foundation guidelines, recently published in the Journal of the American Academy of Dermatology. “When the disease becomes greater than 5% or 10% of body surface area, it’s difficult to manage this solely with topical agents, and then you have a choice of phototherapy or some type of systemic or biologic agent. Most insurance companies require that you either do phototherapy or a systemic agent before you go to a biologic.”

To establish the new guidelines, which update those published in 2010, a working group reviewed a total of 56 articles published from January 2008 to December 2017 to explore the clinical trial efficacy, real-world effectiveness, and safety of phototherapy options, including targeted ultraviolet B (UVB), narrow band (NB)-UVB, psoralen and ultraviolet radiation (PUVA), and Goeckerman therapies.

According to Elmets, the literature shows that phototherapy offers the potential for substantial improvement and even complete clearance of psoriatic skin lesions, with minimal light source-related adverse effects beyond phototoxic erythema.

Despite their effectiveness, Elmets noted that light modalities remain underused, largely due to accessibility and insurance coverage issues. But he hopes the new guidelines will spur more physicians to consider phototherapy as a psoriasis treatment option.

NB-UVB Therapy Recommended

Front and center in the guidelines is NB-UVB therapy, a treatment that at 311-313 nm is “more precise” than traditional UVB therapy, and has been used “for many years with great efficacy,” the guidelines read.

“This is a nice compromise between a broad band UVB, because it has increased effectiveness, and PUVA, because it has fewer side effects and works almost as well,” Elmets told the AAD Reading Room.

The AAD/NPF guidelines specifically recommend NB-UVB phototherapy as monotherapy for adults with plaque psoriasis, ideally given 3 times a week because skin clearance takes about 1.5 times as long when twice-weekly treatments are given.

NB-UVB has been proven effective in multiple clinical trials and analyses. In a systematic review and meta-analysis of 293 patients in 9 randomized controlled trials, 62% of patients receiving NB-UVB monotherapy had an improvement of 75% in Psoriasis Area Severity index score (PASI).

Oral PUVA Versus NB-UVB

Oral PUVA appears more effective than NB-UVB. A meta-analysis of 3 clinical trials, for instance, reported a PASI 75 rate of 80% for PUVA versus 70% for NB-UVB. Other studies have noted that skin clearance is comparable between the two modalities but that PUVA offers faster clearance.

NB-UVB is also recommended over broadband (BB)-UVB. “Although effective, BB-UVB is less effective than oral PUVA and NB-UVB for the treatment of plaque-type psoriasis,” the authors wrote. Moreover, BB-UVB has proven less effective than topical PUVA for palmoplantar psoriasis treatment.

Overcoming Barriers with Home Phototherapy

Access to NB-UVB, however, remains a challenge for many patients. Elmets noted that home NB-UVB may be a way to overcome that barrier.

The guidelines say that despite the “general impression” of some dermatologists that home devices don’t work as well as office-based ones, studies have demonstrated comparable efficacy. In one study of 196 patients with moderate to severe psoriasis, a PASI 75 was achieved in 40.7% of patients receiving home phototherapy compared to 41.7% of those who had hospital-based treatments.

“The patients liked [the home-based option] much better, and there was no increase in side effects with home phototherapy, so I think many patients would prefer it,” Elmets said.

NB-UVB Combos (Including Biologics)

Some combination NB-UVB regimens are recommended, though tend to come with lower levels of evidence compared to NB-UVB monotherapy. Vitamin D analogues, retinoids, and corticosteroids are safe to combine with phototherapy and might improve efficacy, according to the guidelines. By contrast, no support exists for combining methotrexate with NB-UVB, and combining cyclosporine with NB-UVB has been linked to an increased risk of skin cancer risk.

But the evidence does show efficacy for combinations of NB-UVB and certain biologics — such as etanercept, adalimumab, and apremilast. The guidelines give a special nod to an apremilast plus NB-UVB combination for treating generalized plaque psoriasis, which does not respond adequately to monotherapy. One study found that 73% of patients who completed the full 12-week treatment regimen (16 of 22) achieved a PASI 75.

Targeted UVB

For localized psoriatic lesions, targeted approaches including excimer laser, excimer light, and targeted NB-UVB are “well suited and recommended for treating localized psoriatic lesions,” according to guidelines, which note that the treatment is generally well-tolerated because typically only small areas of the skin are treated. In one analysis, an estimated 61% of patients achieved PASI 75 with targeted UVB treatments. Another study found that about 85% of patients achieved a PASI 90 following 7 to 13 treatments of 308-nm excimer laser therapy .

Climatotherapy and Other Approaches

The guidelines also touch on a variety of other light wave therapies. Goeckerman therapy, for instance, has “ample evidence” to support its effectiveness, but is no longer commonly used because of the “messy and cumbersome nature of tar application and the wide availability of highly effective NB-UVB.”

Climatotherapy — which involves temporarily or permanently moving to regions with favorable climates and natural resources that support psoriasis therapy — is another promising approach, but studies have suggested a key limitation: The “apparent transient nature” of its effects.

“The improvement in psoriasis severity and psychologic health seems to wane after a few months, although there have been no formal studies on the remission duration associated with climatotherapy,” Elmets and co-authors wrote.

Overall when it comes to patient care, Elmets and colleagues recommend that discussing efficacy and safety data with patients to help make an informed decision regarding initiating phototherapy, switching phototherapy modalities, or adding topical or systemic agents to phototherapy.

LAST UPDATED 10.01.2019