Pfizer Inc's

purchase of Anacor Pharmaceuticals Inc heralds an approaching wave of potentially safer and more effective treatments for millions who suffer from eczema, a common skin condition which causes infection-prone rashes that can feel like having poison ivy 24 hours a day.

More than two dozen drugmakers are working on novel medicines to treat the condition affecting about 20 million Americans, also known as atopic dermatitis, and Pfizer's $5.2 billion deal positions it to become a market leader.

Anacor's steroid-free topical ointment crisaborole is the first of the new treatments to be reviewed by U.S. regulators. An injectable therapy called dupilumab from Regeneron Pharmaceuticals Inc is expected to be submitted for U.S. approval later this year.

"Until a few years ago, I don't think we had any message of hope for eczema patients who have tried everything," said Gil Yosipovitch, chairman of dermatology at Temple University School of Medicine who is a paid consultant for both companies. “Now we do.”

The two medicines greatly reduced eczema symptoms in late-stage trials without side effects accompanying current treatments. They could eventually see combined annual global sales of over $9 billion and face no significant competition for years.

Yosipovitch said Anacor’s crisaborole could be a valuable option for the 60 percent to 80 percent of patients with mild and moderate eczema on localized areas of the body. Dupilumab would be used for patients with more severe disease, he said.

The global eczema drug market is currently worth about $4 billion in sales, mostly of topical steroids than can cause skin atrophy and increase risk of glaucoma and cataracts. Doctors may also prescribe oral drugs that suppress the immune system, such as cyclosporine, but they are not approved for eczema and can cause infections, shingles and cancer. There are no approved systemic drugs for the condition.

However, the cost of the new treatments may limit patient access. Regeneron's injectable dupilumab could cost $25,000 a year, similar to psoriasis drugs, at a time when U.S. health insurers are resisting rising drug prices. Analysts say it could eventually capture annual sales of $6 billion, with Anacor's drug costing more than $1,200 a year and having peak annual sales of up to $3 billion.

"Payers know this will be a big market and will put up a lot of barriers and restrictions," said Yatin Suneja, an analyst with Suntrust Robinson Humphrey.

Express Scripts Inc last month said it would scrutinize new eczema treatments and their expected prices.


Crisaborole blocks an inflammation-causing protein called PDE-4. In large clinical trials that included children and adults, it cleared or almost cleared treated areas of skin in half of patients with mild to moderate disease, with mild side effects.

"We badly need a nonsteroidal topical that can get around serious steroid concerns and this drug showed no skin atrophy or other significant side effects," said Dr. Lawrence Eichenfield of the University of California San Diego and lead author of American Academy of Dermatology eczema treatment guidelines. Regeneron and Sanofi aim to seek approval for dupilumab this year for adults with moderate to severe eczema. It blocks two proteins, IL-4 and IL-13, believed to cause eczema and allergic conditions like asthma.

In big trials, dupilumab led to an average 70 percent improvement in rash area and severity. Fewer serious side effects, including infections, were reported for dupilumab than for placebos. In separate studies it reduced incidence of asthma.

One concern over drugs like dupilumab, which regulate the immune system, is potential for serious side effects over time, including lymphoma. Such problems typically do not show up until a patient has used a medicine many years, said Dr. Cameron Rokhsar, a New York dermatologist with no financial ties to the drugmakers.

Roche Holding AG and AstraZeneca Plc are developing injectable eczema treatments several years behind dupilumab.

Data from mid-stage trials of the Roche drug, lebrikizumab, are expected in the second quarter. AstraZeneca plans this year to disclose data from a mid-stage trial of its tralokinumab in adults with moderate to severe eczema.

Nemolizumab from Japan's Chugai <4519.T> is also being tested in a mid-stage trial. The injectable drug targets IL-31, a protein associated with itch, a hallmark of eczema.

"The main concept of our drug is to break the vicious itch-scratch cycle because scratching damages the skin and causes more intense inflammation," Dr. Michiaki Tanaka, a senior Chugai research executive, said in an interview.

Celgene Inc recently tested its psoriasis drug apremilast in about 200 patients with moderate to severe eczema.

It has not publicized the results, but researchers and analysts say it could become the first approved oral treatment for eczema. The pill has caused nausea and other gastrointestinal problems in psoriasis patients. "I'm very excited about apremilast because we have no approved oral drug for eczema," said Dr. Emma Guttman-Yassky of Mt. Sinai Medical Center in New York. She helped conduct trials of apremilast and dupilumab.

(Reporting by Ransdell Pierson; Editing by Michele Gershberg and Bernard Orr)