Dwindling Supplies of Critical Cancer Drug BCG

Vials Being Rationed, Only One Manufacturer

Bacillus Calmette-Guérin, commonly known as BCG, is in short supply across the country. Many small clinics have now run out of the lifesaving cancer drug and larger hospitals have changed their policies so that newly diagnosed patients receive the drug first.

Drug shortages are very common in the U.S. and can be caused by natural disasters at production plants or increased demand during an outbreak. But sometimes, there is little incentive to produce a drug like BCG, especially when it’s difficult to make or doesn’t generate much income for the manufacturer. It takes about three months to make BCG, which is grown on a particular variety of potato. After being harvested, it brews in huge vats for a month. But sometimes entire batches can be ruined simply through the push of a wrong switch or by one wrong chemical getting into the vat.

A live, weakened, strain of Mycobacterium bovis, BCG was initially used as a tuberculosis vaccine in 1921. Several decades later, researchers found that if live, attenuated BCG bacteria were introduced directly into a cancer patient’s bladder, they stimulated T cells to attack tumors. Since then, BCG has been the standard of care for certain types of bladder cancer. It beats surgery and chemotherapy at keeping tumors at bay, and is much cheaper.

Annually, there are some 80,000 new cases of bladder cancer in the U.S., and it is the country’s sixth most prevalent cancer. About 20% of those cancers can be treated with BCG; it doesn’t work for everyone but the response rate is greater than 70%. Clinicians continue to check for cancer every three to six months after initial dosing, and give additional doses of BCG to ensure the cancer remains in remission.

For now, the Bladder Cancer Advocacy Network, the American Urological Association, and several other physician groups have devised treatment guidelines to help navigate the shortage. They suggest dividing up doses–– there are studies suggesting that lower doses are just as effective at treating bladder cancer––or stopping maintenance therapy entirely.

Merck is the sole manufacturer of BCG for the U.S. and European markets. The company says it is working at capacity to produce more of the drug and fully intends to continue production for the foreseeable future. This despite the low-cost of a BCG dose, around $100–$200, which makes it virtually non-profitable for Merck. Simultaneously, companies in Japan, Canada, and Europe are developing their own strains of BCG; this could ease future shortages of the drug if they receive FDA approval.

Source: StatNews, February 20, 2019