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After building new plant and signing on with AbbVie, Regenxbio enters commercial phase

ROCKVILLE, MARYLAND—Regenxbio CEO Ken Mills motions toward a window pointing out a building to the north, barely visible beneath a small grove of trees.

“That’s where we used to be,” Mills said. “There’s a gym in there now.”

Mills is speaking from the conference room of Regenxbio’s new home in a tech hub in Rockville, Maryland. On a crystalline summer day as Mills gazes out the window, he has a clear view of his company’s tantalizing future.

For more than a decade, Regenxbio has made noise as a developer and manufacturer of gene therapies. It first hit the jackpot with the 2019 approval of Novartis’ blockbuster Zolgensma, which uses Regenxbio’s NAV Technology platform. Now, the company is entering a new phase—with its new building as tangible evidence of its arrival as a burgeoning commercial business.

Two weeks earlier, Mills cut the ribbon on Regenxbio’s $65 million top-floor manufacturing facility, which was largely made possible by a transformational deal with AbbVie.

Ken Mills (Regenxbio)

In September of last year, the Illinois Big Pharma paid $370 million upfront to collaborate on Regenxbio’s phase 3 gene therapy, RGX-314, for retinal diseases including wet age-related macular degeneration (AMD). Previously, the company worked through a 2019 FDA hold on the prospect and sued the agency over the trial halt.

“We’ve had a heck of a time trying to grow from an idea to people who are really going to deliver medicines to people,” said Mills, who established the company in 2009.

In the cell and gene therapy arena, Regenxbio is somewhat unique. While many companies are developing one-time therapies for diseases that have tiny populations and others are pursuing treatments in oncology, Regenxbio is taking on one of the most common causes of blindness.

“We’re gonna be the first company to commercialize gene therapy for a really large indication,” Mills said. “We’ve got a number of challenges in bringing gene therapy more into the public focus.”

For one, it will take an extensive education campaign to assure patients and retinal specialists that the therapy is safe and effective, Mills said. The top selling point is obvious. As a one-time treatment, the gene therapy would eliminate the need for patients to visit their doctor every few months to receive a needle in their eye, a routine that leads many to noncompliance. The downside, of course, would be the cost.

“We’ve got to make it economically feasible,” Mills said.

To take its act around the world, a Big Pharma was needed. Throughout its history, Regenxbio had already partnered with many large companies, but AbbVie was not among them. After its acquisition of Allergan, however, AbbVie announced that it was targeting diseases of the eye as a new growth area. Enter Regenxbio.

“We’ve been able to grow quickly, but we didn’t have the global reach,” Mills said. “We decided we needed a geographic partner to be able to grow the program as quickly as the science was moving. We were looking for someone that could help us reach Europe, Japan and China.”

New plant

One area where Regenxbio doesn’t need help is manufacturing. The company’s new facility now ranks among a handful of the largest gene therapy plants in the industry, capable of handling the company’s growing manufacturing needs over the next three to five years.

The facility includes two 2,000-liter suites, which mirror each other and together can produce 40 to 60 batches of adeno-associated virus vectors annually.

“A lot of companies make the mistake of building a clinical facility and they don’t necessarily do the fit and finish that you would want for a commercial facility,” Regenxbio’s manufacturing chief Curran Simpson said. “We built this facility to a commercial standard, anticipating that it would be used for commercial production.”

Simpson is thrilled to finally have his entire team—quality, engineering and analytical—together in the building where the manufacturing takes place.

“The beauty is you have the developers of the process on hand during the whole run,” Simpson said. “We’ve been operating seven years or so virtually, flying people to different CMOs to be person in plant. This is going to be so much better going forward.”

The last production piece to be added will be the fill-finish. That should be done by spring of next year.

“It will be manufacturing ‘Independence Day’ for us,” Simpson said. “We’ll have control over the whole supply chain.”

Getting started

When Mills founded Regenxbio—spun out of the gene therapy program at the University of Pennsylvania led by Jim Wilson, M.D., Ph.D.—there was no private funding available in the arena, which then was considered eccentric.

“It was unaccepted,” Mills said. “It was shunned.”

But from the start, Mills said he envisioned Regenxbio growing quickly, much like companies such as Biogen, Amgen, Genzyme and Genentech which took off in the 1980s after tapping into brand-new innovations and now are in the mainstream.

In the early days, Regenxbio got by on government grants and by selling gene therapy vectors as reagents. Five years into its existence, the company still had only six employees but had racked up a dozen or so biotech partners by licensing its NAV technology. It also was using NAV to develop its own gene therapy candidates.

The company’s NAV technology incorporates the “capsid” or an outer shell, Mills said, and the DNA inside of it. Lastly, the platform includes the manufacturing technology and process for making gene therapies.

“We have these novel capsids that were discovered in the mid-2000s that we’ve been sharing with everyone and that we’re using ourselves that are just better than anyone had ever seen before,” Mills said.

In 2015, Regenxbio went public with a raise of $159 million. That followed two rounds of private financing worth more than $100 million.

What’s next?

Regenxbio is growing rapidly—doubling its employee count to 400 over the last two years—and figures to continue the trajectory. It has a “5 by 25” plan in which it expects to have five pipeline programs either in late-stage studies or under FDA review by 2025.

In addition to its wet AMD candidate, Regenxbio has programs in phase 1/2 to treat diabetic retinopathy, Duchenne muscular dystrophy and the neurodegenerative disorders Hunter syndrome and Hurler syndrome.

It’s all uncharted territory for the company. But Simpson says his group is prepared for the challenge thanks to an influx of employees with commercial experience—even if it is from biologics manufacturing.

“Many of the people in my team have commercial experience, so we’ve got a lot of institutional knowledge about how to do this late-stage work,” Simpson said. “I think that differentiates us in the gene therapy field.”

Meanwhile, Mills is relishing the challenge of breaking new ground. In licensing its technology to Novartis for Zolgensma, the companies make a therapy that treats roughly one child a day. The trick for Regenxbio with AMD is figuring out how to treat roughly 100 people per day.

“It’s just not been done—the supply chain, the delivery of genetic medicine, that one-time treatment,” Mills said. “It’s gonna be fun. It’s going to be amazing. And it’s going to turn it into this mainstream thing.”