Understanding the Status of the BCG Shortage
Worldwide shortages continue to affect the ability of people with non-muscle-invasive bladder cancer (NMIBC) to receive Bacillus Calmette-Guérin (BCG), the gold standard in treatment.1 In the face of the COVID-19 pandemic, the healthcare system continues to urgently focus on addressing the needs related to the novel virus. As a result, the BCG shortage persists and doctors and researchers continue to re-evaluate the situation.
How BCG was created
BCG was created after 230 recultures of the pathogen M. Bovis (the B in BCG). Scientists Albert Calmette (the C) and Camille Guerin (the G) showed that bacillus protected animals against tuberculosis. BCG was then used to prevent tuberculosis in humans and remains the only available tuberculosis vaccine.
Treating bladder cancer
Years later, doctors found that mixing two other bacteria and BCG could be used to treat cancer. By the 1970s, BCG was officially approved as the standard treatment for bladder cancer patients. The treatment protocol involves weekly doses of BCG over 6 weeks (induction) followed by 6-week periods of additional doses every 3 months for 1 to 3 years (maintenance).
What caused the BCG shortage?
There are several reasons for the shortage of BCG. The first is that there have been manufacturing restrictions placed on its production. Second, due to the slow growth of mycobacteria, BCG is extremely hard to make.
When did the shortage begin?
Shortages initially began in 2012 when a Canadian factory (BCG Conaught) discovered mold in their facility. BCG Conaught was forced to close, which stopped BCG production. At that time, the company was the main source for BCG treatment in North America and Europe. In 2017, BCG Conaught exited the market completely.
Production has slowed down
Other companies have also had slowdowns of BCG production in the last 5 years, further increasing global scarcity. Now the only source for several Western countries, Merck, has increased BCG production by more than 100 percent. Despite this increase, Merck is still experiencing supply constraints. And, as other global suppliers of BCG have depleted their stocks, worldwide shortages have become common.
While it would be ideal to import BCG from other countries, regulatory hurdles stand in the way. Clinical trials would need to be conducted to introduce new substrains. One such trial is being conducted by the SWOG Cancer Research Network in the U.S. Only time will tell if that trial bears fruit for those affected by the shortage of BCG.
Alternative treatment options
The scarcity of BCG has had an impact on the recurrence and progression of NMIBC for many people. Doctors have been forced to re-evaluate the established treatment guidelines for this type of bladder cancer. Some doctors are decreasing the length of maintenance treatment. Others are reducing the size dose of BCG. Others are using different substrains of BCG. And, still others are opting to remove the bladder entirely.
Since the shortage has now lasted for many years, several new treatment protocols are being studied, including:
- Combining BCG with other chemotherapeutic or immunotherapeutic options
- Using a virus as a vehicle to specifically introduce genetic material into tumor cells
- Using live or nonviable bacteria to treat the tumor
- Using chemotherapeutic agents such as hyperthermia during induction
- Using device-assisted therapies to improve the effectiveness of chemotherapy
- Using checkpoint inhibition therapies to rescue the suppressed immune response
As long as BCG remains the gold standard for NMIBC treatment and is hard to get, research in BCG alternatives will and must continue. Most new options are being tested on people who do not respond to BCG. Doctors are still trying to understand why BCG works on a large number of patients but not at all in others.
What topics are you most interested in learning about? (Choose up to 3)