Virus Shortages Can Halt Gene Therapy Development

The U.S. Food and Drug Administration announced that it will expedite approval of experimental gene therapies. However, when it comes to developing potentially curative treatments, the regulatory process may not be the greatest hurdle.

Some biotech companies are having difficulty obtaining disabled viruses, a critical component of the gene therapy products they are eager to test. Disabled viruses are necessary for many forms of gene therapy, and manufacturing them can be costly and burdensome. Standards are exacting and comprehensive for viruses used in clinical trials, and few gene-therapy companies have the facilities to make them. The companies that do are backed up with orders.

Even when a company does have a manufacturer lined up, it is still in a precarious situation, as Bluebird Bio can attest. The company formed in 2010 hoping to develop a gene therapy for a rare neurodegenerative disease.  Months into production, the manufacturer discovered that it was unable to create any viruses using Bluebird’s recipe. They eventually found the source of the problem – the acidity of the solution used to grow the viruses was slightly off, killing them.

To produce tisagenlecleucel, Novartis signed up years in advance with Oxford BioMedica, agreeing to three contracts that add up to $195.2 million and include a provision to pay Oxford a share of the drug’s royalties. Manufacturing custom-made viruses can cost biotech firms a third or more of their development budget.

Smaller companies are not always able to afford such costs, and investors are wary of companies that do not have ready source of viruses. “You’ve got to believe that every time someone gives a pitch to an investor, the investor will say, ‘What are you doing about manufacturing?’” Jim Wilson, MD, director of the gene therapy program at the University of Pennsylvania’s Perelman School of Medicine, told The New York Times.

The cost of a new treatment can depend on how many patients will take the drug and how many cells from each patient must be altered by a virus. Today, creating viruses to deliver gene therapy to the lung or liver can cost as much as $3 million per patient, according to John Dawson, chief executive of Oxford BioMedica. Methods are improving, Mr. Dawson told The New York Times, and his expectation is that it might cost $30,000 for the viruses in the future.

Source: The New York Times, November 27, 2017.

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