The new approaches include a regenerative injection designed to be administered directly into a joint, as well as a biomaterial-based repair system that encourages the body’s own cells to rebuild damaged cartilage.

The work recently received a major boost from the federal Advanced Research Projects Agency for Health (ARPA-H), which announced that the team will move forward to the next stage of a project worth up to $33.5 million. The research is part of the ARPA-H Novel Innovations for Tissue Regeneration in Osteoarthritis (NITRO) program, led by ARPA-H Program Manager Dr. Ross Uhrich.

“In two years, we were able to go from a moonshot idea to developing these therapies to demonstrating that they reverse osteoarthritis in animals,” said principal investigator Stephanie Bryant, professor of chemical and biological engineering at CU Boulder. “Our goal is not just to treat pain and halt progression, but to end this disease.”

A New Approach to Osteoarthritis

Osteoarthritis is the third most common disease in the United States and affects roughly one in six people over age 30 worldwide. The condition gradually breaks down cartilage, the cushioning tissue that prevents bones from rubbing against each other. As the disease advances, it can also damage bone, alter joint structure, and make everyday movement increasingly painful.

Current treatment options are limited. Most patients either manage symptoms through pain relief or eventually undergo joint replacement surgery. There is currently no cure for the disease.

The Colorado researchers are pursuing two different strategies aimed at changing that reality.

One treatment repurposes an existing drug that has already received approval from the Food and Drug Administration. Bryant and her colleagues created a patented particle delivery system that can be injected into a joint, where it releases periodic doses of the drug over several months.

For patients with more extensive damage to cartilage or bone, the team developed a separate therapy consisting of engineered proteins. Delivered arthroscopically, the material hardens in place and attracts the body’s own progenitor cells to repair the damaged area.

Rapid Joint Repair in Animal Studies

When researchers tested the injectable treatment in animals with osteoarthritis and joint injuries, the affected joints returned to a healthy state within four to eight weeks.

The repair material also produced striking results. According to Bryant, filling defects in cartilage or bone led to “full regeneration and repair of the defect.”

The therapies also showed regenerative effects in human cells obtained from patients undergoing joint replacement procedures.

NITRO was the first program launched by ARPA-H and was established to develop “minimally invasive therapeutics that fully regenerate damaged joints.” Two years ago, the program awarded the Colorado team up to $33.5 million, contingent on positive results, to pursue that objective.

With the successful completion of phase one, the researchers have now advanced to phase two.

“It’s super exciting to be a part of the very first program of ARPA-H and to be one of the first teams to advance to the second phase,” said Bryant.

Looking Ahead to Human Trials

Dr. Evalina Burger, professor and chair of the Department of Orthopedics at CU Anschutz, said osteoarthritis affects people from all walks of life. She has seen the disease impact grandparents who struggle with simple daily tasks because of shoulder pain, as well as athletes forced to give up running, hockey, and other activities due to knee or back problems.

“At the moment, the options for many patients are either a massive, expensive surgery or nothing. There’s not a lot in between,” said Burger, who has been following the team’s research with interest. “That’s why ARPA-H is so important.”

Burger and Bryant envision a future in which people with early-stage osteoarthritis could receive an affordable one-time treatment that keeps their joints healthy for years. Patients with localized cartilage or bone injuries could potentially have damaged tissue repaired during a single office visit and recover quickly.

The researchers plan to publish their animal study results in a peer reviewed journal later this year. They have also launched a company, Renovare Therapeutics Inc., to help move the technology toward commercial use.

If future research continues to produce positive results, Bryant believes clinical trials could begin in as little as 18 months.

“This could be a real game-changer for patients,” said Bryant.