Multiple myeloma is a B-cell cancer caused by malignant plasma cells. It's a tough-to-treat cancer, with many patients undergoing multiple treatments over time. Eventually, patients whose disease returns despite receiving multiple prior treatments are left with few treatment options. Eventually, that could change if early-stage trial results reported by bluebird bio (BLUE +0.00%) are confirmed in future trials.
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First, some background
B-cells are immune system cells that fight infection and disease. When B cells attack infection, they mature into plasma cells that make antibodies and that are mostly found in the bone marrow, or the soft tissue that's found inside some hollow bones.
When B-cells are cancerous, they can produce tumors in the bone, as well as other places. If a patient has more than one tumor, then that patient is diagnosed with multiple myeloma. Eventually, cancerous cells in the bone marrow crowd out normal blood cells, and proteins released by them can build up and organ damage.
According to the National Cancer Institute, over 30,000 new cases of myeloma are diagnosed in the U.S. every year. Currently, theses patients are treated with various approaches, including biologics, such as Celgene's (CELG +0.00%) Revlimid, corticosteroids, chemotherapy, and stem cell transplants. If a patient's disease returns, or it fails to respond to a treatment, then a different treatment option is tried. Unfortunately, this approach falls short for many multiple myeloma patients, and as a result, the five-year survival rate for the disease is only about 50%.
A big market
Revlimid is one of the top-selling drugs in the world, with third-quarter sales of $1.9 billion, up 30% year over year, and expected full-year sales of "approximately $7 billion." Revlimid is commonly used in first- and second-line treatment of multiple myeloma, but Celgene also markets Pomalyst, which is commonly used in the third-line setting. In the third quarter, Pomalyst sales were $341 million, up 33% from a year ago.
Other multiple myeloma drugs that are used in treatment include Velcade, Kyprolis, Darzalex, and Empliciti. Often, these other drugs are used in combination with Revlimid.
Overall, GBI research estimates that the global market for multiple myeloma treatment was worth $7.3 billion in 2014 -- and that it will grow to be worth nearly $9 billion in 2021.
A major advance
In patients who have exhausted current available treatments, Bluebird may someday provide a new option.
Yesterday, Bluebird announced interim results from a small, nine-person study of bb2121, a chimeric antigen receptor T-cell therapy (CAR-T) that targets BCMA, a protein selectively expressed by B-lineage cells, including multiple myeloma cells.
The company's ongoing phase 1 trial is designed to establish a safe dose of bb2121; however, in addition to reporting that there were "no dose-limiting toxicities to date, no grade 3 or grade 4 cytokine release syndrome or grade 3 or grade 4 neurotoxicity observed," the company also reported that 78% of patients responded to bb2121, including two patients who remained complete responders at the four- and six-month marks, respectively.
The results are incredibly intriguing because, on average, patients participating in this trial had seen their disease return despite having already received a median six prior therapies. Further, the absence of dose-limiting toxicity suggests that higher, potentially more-effective doses can be evaluated further in future studies.
Looking ahead
There's a long development road ahead for bb2121, but Bluebird is partnered up with Celgene on bb2121's development, so there's a lot of experience and insight available that could help speed this drug's progress along.
According to ClinicalTrials.gov, complete data from this phase 1 trial of bb2121 isn't expected until 2018, and afterwards, bb2121 will likely have to be proven safe and effective in additional, larger studies before an application for approval can be filed with the FDA.
Nevertheless, bb2121's early results hint at a potential to someday reshape multiple myeloma treatment, and that potential shouldn't be ignored altogether. After all, this is a big and important market, and the FDA has shown a willingness to accelerate drugs that target cancer to market.
