Top biotech executives say this is the 1 challenge that startups flooding into gene therapy could face

Top biotech executives say this is the 1 challenge that startups flooding into gene therapy could face

FILE PHOTO: A technician works with genome samples at a lab of the biotech company Sinogene that specialises in dog cloning, in Beijing, China June 15, 2018. REUTERS/Thomas Peter/File Photo

  • New drug companies are flooding into the promising field of gene therapy because of its tremendous potential to treat disease at its genetic root cause.
  • But the field has also long been plagued by issues of patient safety, something that top biotech executives said continues to be a problem to this day.
  • The executives, from Spark Therapeutics, AveXis, and Bluebird Bio, talked about how their companies navigated this challenge at the Gene Therapy for Rare Disorders conference in Boston on Wednesday.

A decades-old scientific technology that targets disease at its genetic root has come of age. New start-ups are pouring into the space - and becoming major acquisition targets.

Top executives from Spark Therapeutics, Bluebird Bio, and AveXis spoke on Wednesday about the challenges they faced to become three of the most prominent biotechs in the space, as part of the Gene Therapy for Rare Disorders conference in Boston.

Spark was acquired by Swiss drug giant Roche earlier this year for nearly $5 billion. Another large Swiss drugmaker, Novartis, bought AveXis last year for nearly $9 billion.

The field has faced serious, longterm challenges around patient safety to get where it is today, and it was a key issue the executives quickly pointed to.


Gene therapies are incredibly complex medicines, and startups can't make assumptions about how their products will work based on how other, similar therapies work, or even based on how their products do when tested out in animals like mice or monkeys, many of the experts said.

"You really have to know your own product," said Spark Therapeutics' cofounder, president and chief scientific officer Katherine High.

Read: Bill Gates is worried about gene editing worsening inequality. Now a top ethicist is raising new red flags.

Avoiding a potentially deadly immune-system response

Gene therapies often involve taking a patient's own cells and making a change at the genetic level to target the source of their disease.

Because of this, though, they can trigger a harmful, and possibly deadly response from the patient's immune system, which is designed to recognize foreign substances in the body in order to fight disease.


See: Drugs that cost as much as a house are on the way to treat rare and devastating diseases. The US is scrambling to figure out how to pay for them.

To predict for that type of response, scientists test out experimental therapies in non-humans first, like mice and monkeys. But those models haven't always predicted how human bodies will respond, Spark's High and AveXis's Chief Scientific Officer Brian Kaspar said.

"I think we were all surprised" by that, High said, adding that the issue likely also posed challenges for the scientists who developed organ transplants, which similarly trigger a life-threatening immune response in the body.

AveXis confronted this by working hard to understand how their products did in each type of animal model, for example, Kaspar said.

"Many people do a mouse study and essentially wave their hands at human models," he said. But "we go through the same process each and every time, on each and every program."