(Bloomberg) -- Gloria Thomas was three years old when she was diagnosed with sickle cell disease, an inherited condition that causes bouts of pain that she says feel “like little pieces of glass going through you.” She’s spent a lifetime in and out of hospitals.

That all changed in the past year. Thomas, now 50, hasn’t been hospitalized since she enrolled in a study of Novartis AG’s crizanlizumab, set to become the first approved drug to specifically target the blood disorder that affects as many as 100,000 Americans.

Thomas, who lives in the tiny town of Toccoa, Georgia, takes a two-hour ride each way to Augusta every month to get an infusion designed to keep her red cells slippery, so they don’t clump together to form painful bottlenecks that choke off the flow of oxygen-rich blood. It’s not a panacea — she still relies on a daily pain pill — but she has been able to ease back on fentanyl skin patches.

“It’s very helpful to me,” Thomas said. “I haven’t had any crises or anything, no major crises.”

After decades of neglect, it’s an exciting time in the sickle cell field, with breakthrough gene therapies in the pharmaceutical pipeline that could one day cure the condition. Patients who, on average, don’t survive past their 40s, won’t have to wait that long to get relief: In the next six months, two new treatments aimed at reducing symptoms including pain and strokes are expected to get approval, Novartis’s drug and Global Blood Therapeutics Inc.’s voxelotor.

Many questions remain, including how much the treatments will cost. Although sickle cell is the most common inherited blood disorder in the world with 250 million people carrying the gene, there are massive gaps in diagnosing, tracking and understanding how it affects patients over a lifetime. Doctors and advocates point to institutional discrimination for a condition that affects mainly minorities such as Thomas, who is African American.

An Old Disease

Sickle cell, a wily disease that causes normally round red blood cells to collapse on themselves, was discovered a century ago. Bone marrow transplants can cure the condition, but the treatment is toxic and can be deadly. Blood transfusions reduce the risk of anemia, stroke and other complications, though they can cause an overload of iron. The few other options include antibiotics; a high dose version of the dietary supplement L-glutamine; and hydroxyurea, a re-purposed cancer medicine approved in 1998 that isn’t widely used because it’s mired by concerns about side effects, including that it may contribute to infertility.

“Patients have been waiting for improved treatments and are very interested in new therapies,” said Abdullah Kutlar, director of the Sickle Cell Center at Augusta University in Georgia and Thomas’ doctor, who led one of the studies of Novartis’s crizanlizumab.

The two new treatments work differently. Crizanlizumab cut pain crises by about half in trials by neutralizing a molecule that causes cells to stick together and create bottlenecks in the blood flow. A study at a higher dose may get better results, though it’s unlikely regulators will wait to approve the drug until that trial is done, Kutlar said.

Global Blood’s voxelotor, a daily pill, plumps up the hemoglobin in red blood cells with additional oxygen, making it harder for them to become sickled and eventually destroyed. It hasn’t been shown to curb the painful attacks but seeks to alter the course of the condition in the longer term. A study published in the New England Journal of Medicine showed it significantly increased red blood cell levels, potentially averting a process that destroys organs and causes strokes.

Blockbuster 

“We’re in the early days of coming to understand there are several sickle cell markets, and more than one could support blockbuster levels of drug sales,” said Mani Foroohar, managing director of genetic medicines at SVB Leerink, an investment advisory firm.

Voxelotor’s annual sales are predicted to surpass $1 billion — blockbuster level in the industry — in 2024, based on estimates compiled by Bloomberg. Projections for crizanlizumab are scanter: one analyst projects sales of $582 million in 2025.

One major development will be the possibility of gene therapy, under development at drugmakers such as Bluebird Bio Inc. Other approaches using gene-editing tools like Crispr to try to repair DNA are generating excitement, but the research is still in its infancy.

“In the meantime, crizanlizumab is a solution that we know works,” said John Tsai, chief medical officer at Switzerland’s Novartis.

Rather than trying to cure the condition, South San Francisco, California-based Global Blood wants to make sickle cell disease manageable, Chief Executive Officer Ted Love said.

“Global Blood was founded with the idea that we could do for sickle cell patients what the world has done for HIV,” Love said. “The idea for voxelotor is to make a small molecule, taken orally once a day, that would stop the fundamental nature of the disease.”

Many patients, like Gloria Thomas, are willing to do whatever it takes to feel better.

“Anything I can qualify for, I would like to try it,” said Thomas, who suffers from shoulder damage — necrosis — from a lifetime of sickle cell. “I’m not shutting the door to anything.”

To contact the editor responsible for this story: Cecile Daurat at cdaurat@bloomberg.net, Drew Armstrong

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