Mariah Leach finds it hard to obtain authorization from her insurer for her pricey biologic drugs. (Courtesy of Mariah Leach)

Correction: An earlier version of this article incorrectly described Mariah Leach’s age as 31, when she was diagnosed with rheumatoid arthritis. She was 25. The article has been updated.

Mariah Leach felt at the top of her game six years ago. At age 25, she was pursuing a law degree and a master’s in environmental policy at the University of Colorado, earning straight A’s and playing water polo with the university’s club team. But then her toes began to hurt. A few weeks, later her knees swelled to the size of grapefruits.

The student health service told her she was anemic. Her hands began to hurt, which she assumed was from too much typing. After more tests, her doctors told her that she had rheumatoid arthritis, or RA. This autoimmune disease affects about 1.3 million U.S. adults and causes pain, swelling, stiffness and eventually deformity of and loss of function in the joints.

Leach began taking prescription-strength nonsteroidal anti-inflammatory drugs and prednisone to reduce her pain and swelling, followed by methotrexate, which doctors hoped would halt the progression of the disease. That chemotherapy drug, though, has significant side effects and works well for only about 30 percent of RA patients. Unfortunately, Leach wasn’t one of them.

So her doctors added a biologic, a class of drugs introduced 15 years ago that seems to help people whose immune system attacks the body instead of protecting it from disease. Almost immediately Leach began to feel better — less exhausted, less in pain. The biologic, she says, gave her her life back.

Biologics have been similarly life-changing for people with multiple sclerosis, Crohn’s disease, psoriasis, psoriatic arthritis, chronic pain and some forms of cancer. (A member of my family who has RA suffered for almost a year with terrible side effects from the standard drugs before moving to biologics.) Sales of these drugs have skyrocketed into the billions of dollars; television ads for Humira, Enbrel and Remicade are hard to miss.

Biologics are different from chemically derived drugs such as antibiotics: They are made from living organisms and require special handling in a controlled temperature while being produced.

Biologics are mostly available through specialty pharmacies. The drugs are primarily given by injection or infusion. They reduce inflammation but also suppress the immune system, which puts users at increased risk of infections and may increase the risk of some cancers, including lymphoma and skin cancer, liver failure and tuberculosis.

“Biologics have lots of different effects on the individual. They are efficacious, very helpful,” said Angus Worthing, a rheumatologist who teaches at Georgetown University Medical Center. “They get people back to work, back to their families, and they save lives.”

“We now have the ability to achieve remission of disease in more than half of our patients with rheumatoid arthritis, along with similar levels of response in other inflammatory diseases,” says Eric Ruderman, a professor of medicine at Northwestern University Feinberg School of Medicine who specializes in RA.

But biologics are very pricey, sometimes costing thousands of dollars a month. While insurers typically cover the standard therapies for RA and other diseases after a patient provides the co-pay, the companies often require the patient to pay a percentage of the biologic treatment’s total cost rather than a fixed co-pay. (On March 6 the Food and Drug Administration opened the door to the sale of somewhat cheaper versions of biologics, called biosimilars, approving a biosimilar version of a drug that helps patients receiving chemotherapy fight off infection. Biosimilars are available in other countries and tend to sell for 20 to 30 percent less than the original product.)

Leach, who now lives in Colorado, was shocked by her first month’s bill for the biologic drug: She was responsible for nearly $1,000 a month out of pocket.

She eventually qualified for assistance from the drug company that reimbursed her most of what she had to lay out. But her drug coverage was capped at about $5,000 a year, a number she hit fairly quickly because of the biologics. She recalls one time when her husband went to pick up her eNbrel prescription and was told she had already hit the cap and he would have to shell out $700 to $800.

Some months, she was able to continue on the drug only because her doctor gave her some of his free samples.

Most insurance companies require a prior authorization for biologics, insisting that a patient and doctor show that less expensive drugs have failed. (In my relative’s case, that took several months of using methotrexate despite the severe gastrointestinal distress it caused.) And that authorization must be renewed every few months.

Brendan Buck, vice president of communication for the trade group American’s Health Insurance Plans, said prior authorizations are designed to make sure the patent is responding positively to a drug before it get regularly prescribed. Patients often want the drugs, which are being marketed to them through advertising, he said, but their serious side effects need to be monitored.

“We want to make sure — just because a patient is told by a drugmaker that [a certain drug] is right for them — that it is without negative consequences before renewing their prescription,” Buck said. “We have a shared incentive with the patient to get better as soon as they can. This process is consistent with that.”

Ruderman says it is reasonable to require patients to try methotrexate first because it is cheaper and it may work. But after that, he believes the decision about which drug or biologic to try should be left to the physician and patient and not decided by an insurer, which for a variety of reasons may have selected a biologic for their approved drug list that is not the best one for that specific patient.

In her six years on biologics, Leach said, getting the approval to refill her prescription has almost always been difficult, requiring repeated calls to her insurance company. Recently Leach’s rheumatologist switched her from Enbrel, which had stopped working, to another biologic, Orencia. And the process of obtaining prior authorization for that drug was even more onerous.

“All this system is doing is making me suffer longer, forcing me to fight for my medications when I am feeling my absolute worst. And something like this seems to happen every single time I call the specialty pharmacy,” Leach said.

Andrew Baskin, the quality performance national medical director for Aetna, Leach’s insurer, said her experience was unfortunate and not typical.

“We are a large company,” Baskin said. “Does everything work perfect 100 percent of the time? No. Does it work right 95 percent of the time? Yes. We try our best to avoid that — it’s not good for us or the patient.”

Yet even with the difficulties in coverage, biologics, doctors say, are clearly worth the effort for the right patient.

Kelly Mack, 37, of Washington was diagnosed with rheumatoid arthritis at age 2. After years on methotrexate, she had some complications; in 2014, her doctor prescribed Enbrel. It took two months before she got authorization from her insurer to use the drug.

“I have severe damage and chronic pain,” she said. “I was excited to start” on a biologic.

Within two weeks, she felt much less pain. “My day-to-day is better,” Mack said. More important, she said, the drug has stopped the disease from getting worse.

Berger is a freelance journalist who writes about health issues. Follow her on Twitter: @Msjournalist.