wbur Narrating Medicine A new category of drugs, biologics, inhibits elements of the immune system that fuel inflammation. Humira is an example of a biologic. (David J. Phillip/AP)

My body is a walking encyclopedia covering 40 years of psoriasis treatments.

I've had hundreds of cortisone injections shot into my scalp, arms and legs. Thick black tar applied to my head so it could be absorbed into the scaly red plaques that surfaced when my condition flared. Salicylic acid shampoos that stunk like hot asphalt. Light box treatments. Methotrexate and cyclosporine, immune system suppressants prescribed variously for cancers, rheumatoid arthritis and organ transplant recipients.

And still, it was there. Always, or nearly always. The inflamed, flaking, cracking skin. Wavy ridges in my fingernails. Hundreds of hours spent in dermatology offices. Thousands of attempts to hide painful, embarrassing skin patches that would appear on elbows, knees, scalp and other surprising places when I was under stress, on a deadline, or for no obvious reason at all.

I am not alone. Last year, the World Health Organizations Global Report on Psoriasis called the disease a "serious global problem with at least 100 million individuals affected worldwide." That includes more than 7 million Americans. We are legion. With lesions.

Psoriasis is a mystery, a disease of the immune system with no clear cause or cure. For years, traditional medications that were developed initially for arthritis, Crohn's disease or other immune conditions eventually dropped down the pharmaceutical food chain to psoriasis patients.

Lately, though, that landscape has been shifting, with the advent of a new category of drugs: biologics, genetically engineered proteins derived from human genes. Usually injections that a patient administers at home, they inhibit elements of the immune system that fuel inflammation.

Humira, Enbrel and Cosentyx are examples of biologics. And a recent paper in The Lancet shows promise for a new biologic called tildrakizumab. Designed primarily for psoriasis, it may ultimately have additional applications.

Tildrakizumab differs from earlier, similar biologics by targeting a very specific immune system pathway.

"The breakthrough is that we have continued to refine our treatments to those that are likely to be most effective against psoriasis but less likely to affect other important pathways at the same time," says study senior author Dr. Alexa Kimball, a dermatologist and presidentof Harvard Medical Faculty Physicians at Beth Israel Deaconess Medical Center in Boston.

From Accidental Findings To'First In Line'

Psoriasis treatments have mostly been accidental discoveries, Kimball said.

Occasionally, a psoriasis patient who needed an organ transplant would end up being treated with cyclosporine, and it was amazing how a drug like that cleared the skin, sheexplained. And so there was this sort of accidental-incidental way that early psoriasis treatments were discovered.

Treatment evolved with those incidental discoveries, including traditional medications such as cortisone and cyclosporine, which are still prescribed frequently for mild to moderate psoriasis.

The first generation of biologics to treat psoriasis entered the market in the early 2000s. They have fewer side effects than traditional medications (the cyclosporine Im currently taking can impact liver and kidney function), are generally well tolerated, and the majority of patients don't mind injecting themselves.

But they still carry the risks of immune suppression, including reactivation of tuberculosis, and increased susceptibility to viral infections and certain cancers.

Immune proteins evolved to protect us from infection, explained immunologist Dr. Sarah Gaffen of the University of Pittsburgh. So when you start blocking them, youre going to raise the specter of some sort of infectious disease.

The good news is that highly focused drugs, like tildrakizumab, do mean greater improvement on psoriasis symptoms with far fewer side effects. Gaffen refers to the targeted nature of biologics as exquisitely specific.

And because psoriasis isnt a life or death matter, patients who are enrolled in research protocols can also be put on placebos with limited risk to their overall health. Thats not an option with arthritis or Crohns disease, where irreversible harm might be done without ongoing treatment. And, as Kimball added, The results are right in front of your face with psoriasis. You can see such a dramatic improvement.

More good news: In drug development these days, psoriasis has been gaining traction as a proof of principle disease, according to Kimball. If a medication did well on psoriasis, it was pretty likely to do well in other [immune] areas.

"The paradigm has completely switched," she added. "Psoriasis was last in line 10 or 15 years ago. Now its often first.

High Hopes, High Prices

Now for the not-so-good news, long familiar to anyone who takes biologics: the price tags.

While tildrakizumab isnt yet on the market, other biologics are, and I was recently introduced to the challenge of acquiring them.

I was having a severe psoriasis flare. Red, cracked, inflamed skin, so painful it was difficult to bend my arms or sit. My dermatologist prescribed Humira.

The prescription was filled before my insurance company had a chance to determine coverage. I asked the pharmacist how much the medication would cost if I paid out of pocket.

She looked at the computer screen, and then at me. Then again at the computer. I raised my eyebrows.

Do you want to guess? she asked me.

$600, I ventured.

She shook her head.

$6,000?

She shook her head again. I shrugged. She paused. $30,000.

$30,000? I repeated. I might as well buy a car.

You should, she said. Because thats not even for the whole year.

Kimball confirmed the cost. Usually we expect these drugs at list prices to run around $50,000 a year. They are very expensive drugs, she said.

Needless to say, I postponed the Humira. I may start on it this fall, when it's fully covered.

In 2016, Humira grossed over $16 billion, putting it in first place for the best-selling drug of the year, according to Genetic Engineering & Biotechnology News, a trade publication.

According to the WHO report, treatments for psoriasis around the world --whether simple creams or complex biologics --are either unavailable or are not reimbursed for the majority of patients. And its hard to imagine anyone paying $50,000 to Walgreens out of a checking account.

Yet biologics offer the greatest advances yet in treating immune-regulated diseases. And tildrakizumab, while developed for moderate to severe psoriasis, may be one that also holds the potential to benefit other diseases in the future.

I hope those of us who need it will have access. Kimball recognizes this hurdle: "Figuring out how to get this right," she said, "so we ensure access to the patients who need these medications, is one of the things that absolutely keeps me up at night."

Beth Jones is a Boston-based writer and educator.

The rest is here:

Progress On Psoriasis, From 'Last In Line' To Often First, But At A Price - WBUR