Home Topics Bioprocessing Mitigating Viral Contamination, a Challenge for Emerging Therapies

Mitigating Viral Contamination, a Challenge for Emerging Therapies

Pipetting sample into tray for DNA testing
Source: Raper: Andrew Brookes/Getty Images

Source: Raper: Andrew Brookes/Getty Images

Mitigating the risk of viral contamination poses a challenge to companies manufacturing new cell and gene therapies.

That’s one conclusion of what is believed to be the first industry-wide study into viral contamination events in biomanufacturing. A consortium of 20 biomanufacturing companies working with researchers at the Massachusetts Institute of Technology (MIT) collected 36 years of data to understand the common causes of contamination, corrective measures to be taken, and the impacts of these events.

Their study, published in Nature Biotechnology in May, found 45% percent of consortium members had experienced at least one viral contamination event. These included the well-publicized contamination of Genzyme’s Massachusetts manufacturing plant in 2009, which led to millions in lost revenue.

However, such events were found to be rare, compared to the total volume of biomanufacturing. Only 26 were recorded between 1985 and 2018.

“It’s fantastic that the biotech industry has a long history of safe production of biological therapies,” says Stacy Springs, PhD, executive director of biomanufacturing initiatives at the MIT Center for Biomedical Innovation, who helped establish the Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB). This is due to the controls put in place to prevent viral contamination, she explains, through selecting low-risk starting and raw materials, testing the manufacturing process for adventitious viruses, and including steps to remove or inactivate them in downstream purification.

She warns, however, that manufacturers shouldn’t become complacent, especially as they move into developing new cell and gene therapies. “There are a relatively small number of viruses that have been problematic over the years,” she says. “But viruses able to penetrate the biopharma environment are cell-line dependent.”

Gene and cell therapies often depend on animal- or human-derived raw materials, which pose the highest risk of contamination. But direct testing of raw materials was of limited value to detect viral contaminants, the study found.

viral safety of autologous cell therapies
Ensuring viral safety of autologous cell therapies may rely exclusively on preventing contamination as virus testing and viral clearance can be challenging. [Betsy Skrip, MIT Center for Biomedical Innovation]
A key conclusion, according to co-author Paul W. Barone, PhD, co-director, biomanufacturing, at the MIT center, is virus safety tor many of these products, especially autologous cell therapies, will rest almost exclusively on preventing contamination, due to challenges in testing and the inability to include viral clearance.