(Bloomberg) -- The US Food and Drug Administration cleared a new treatment from GlaxoSmithKline Plc for a rare blood cancer, bolstering the UK pharmaceutical company’s push back into oncology.

The drug can be used by patients with a cancer of the bone marrow called myelofibrosis who have anemia, regardless of their prior therapy, the company said Friday after reporting it received approval from the Food and Drug Administration. GSK gained the medicine through last year’s $1.9 billion acquisition of US biotech Sierra Oncology.

The medicine, momelotinib, is likely to garner sales “comfortably” above $1 billion a year, according to Luke Miels, the drugmaker’s chief commercial officer. GSK will price it at a premium to its main rival, Miels said in a telephone interview, because anemia is the prime reason patients stop treatment for the cancer, which disrupts the production of blood cells.  

“We’re addressing the anemia issue, which is expensive and obviously a high burden,” Miels said. 

Incyte Corp.’s best-seller ruxolitinib, known commercially as Jakafi, is currently one of the main treatments for myelofibrosis, which affects about 25,000 people in the US. It has a list price of about $17,500 a month, Miels said, declining to disclose momelotinib’s future cost.

The approval caps a tumultuous journey for the medicine, which will be sold under the name Ojjaara. Sierra bought the drug from Gilead Sciences in 2018 after it disappointed in a clinical trial that pitted it against ruxolitinib. A subsequent study found the once-a-day oral treatment benefited a subset of patients with anemia, reducing the need for blood transfusions. 

Cancer Push

About 40% of patients with myelofibrosis have moderate to severe anemia at diagnosis, and almost all will develop it over the course of the disease, according to GSK. Doctors have limited options for these people, and more than 30% stop treatment due to anemia. 

“You’ve got 25,000 patients and just under half of them have anemia, which gets worse when you use the standard of care today,” Miels said. “If it gets worse, their life expectancy is reduced, and we’ve got a drug which is going to be very effective.” 

Under Chief Executive Officer Emma Walmsley, GSK has worked to rebuild its oncology pipeline after it sold off its cancer drugs portfolio to Novartis in 2015. GSK spent $5 billion on the oncology developer Tesaro in 2019 before buying Sierra last year. 

The latest transaction is a “case study of the type of business development we want to do,” with a deal size of about $2 billion to $3 billion, according to Miels. 

When GSK ran the numbers on the Sierra takeover, it used a worst-case scenario in which momelotinib would be prescribed only to patients who had already been treated with ruxolitinib. The FDA’s approval also includes newly diagnosed patients with anemia, meaning the drug has a “significantly larger opportunity than when we did the economics of the deal,” according to Miels.  

GSK has also applied for regulatory approval in the UK and Europe.  

--With assistance from Madison Muller.

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