SAN DIEGO, CA, USA I May 18, 2023 IRejuvenate Bio, today announced new data for its gene therapy RJB-01 from a pilot study in canines with myxomatous mitral valve disease (MMVD), at the 26th Annual Meeting of the American Society of Gene and Cell Therapy (ASGCT), held May 16-20, 2023, in Los Angeles, California.

RJB-01, expresses the genes FGF21 and sTGFßR2 with an adeno-associated virus (AAV) delivery system in order to upregulate FGF21 and downregulate TGFß1 for the treatment of heart failure. MMVD is a common heart valve disease in dogs where the heart valve becomes thickened as a dog ages, causing leakage at the valve that eventually leads to heart failure. The purpose of the study is to determine whether RJB-01 can help delay the progression of this disease.

Results were reported from a subset of the company’s pilot study of RJB-01 in Cavalier King Charles Spaniels (CKCS) for MMVD. Of all the dogs afflicted with MMVD, Cavalier King Charles Spaniels have one of the highest breed incidences, with rates approaching 80%. MMVD is easily diagnosable with a stethoscope as it initially presents as a heart murmur and is confirmed with an echocardiogram.

“Mitral valve disease is often fatal for canines at the advanced stage, with no current treatments that can provide a cure. The disease is caused by a malfunction of the mitral valve, which causes congestive heart failure,” said Noah Davidsohn, Ph.D., Chief Scientific Officer, Rejuvenate Bio. “The current standard of care is Vetmedin® (pimobendan), paired with ACE inhibitors, but this only treats symptoms and does not address the underlying disease. We’re excited to share these initial results from our pilot study at ASGCT 2023 and we will continue to provide updates as the study progresses.”

Pilot Study Results

RJB-01 has been administered to 17 canines approaching 3 years of durable expression and bioactivity of our genes with a favorable safety profile. These dogs were monitored hourly during administration when given RJB-01 in a pilot trial to treat mitral valve disease. Four dogs have been on the therapy for greater than two years with no safety signals.

Twelve Cavalier King Charles Spaniels administered RJB-01 and pimobendan, the current best in class medication to treat dogs with congestive heart failure, experienced a delay in progression of over 1.5 years when compared with the reported time to progression in all breed treated with standard of care. When compared to a historical control of pimobendan alone in all breeds, CKCS treated with RJB-01 and pimobendan saw an increase in time to progression of ~600 days, and over 800 compared to placebo.

Dogs with MMVD often see an enlargement in the left atrium of their heart due to damage caused by a malfunctioning mitral valve. Pimobendan limited the increase in heart size to 0.8 units over 28 months. Excitingly, Rejuvenate’s gene therapy in conjunction with pimobendan was able to reduce left atrium size by 0.3 over a similar timeframe with some dogs reverting to an earlier stage of the disease.

About Rejuvenate Bio

Rejuvenate Bio is a spinout from the Wyss Institute at Harvard focused on reversing aging and eliminating age-related disease. Rejuvenate Bio utilizes gene therapy, proprietary targets, and tools to bring treatments to patients suffering from age-related conditions. The company is developing a pipeline of therapies with applications in cardiac and metabolic disease. The company raised a Series A financing in 2021 led by Kendall Capital Partners, Digitalis Ventures, KdT Ventures and V Capital. Rejuvenate Bio is based in San Diego for more information, visit

SOURCE: Rejuvenate Bio