Rejuvenate Biomed NV

Rejuvenate Biomed is a clinical-stage biotech company. It uses AI to develop combination therapies of existing approved drugs to impact age-related diseases. It has a pipeline of assets for COPD-related sarcopenia, muscle weakness, and other age-related conditions.

The CombinAge™ AI discovery engine finds combinations of approved drugs. These drugs potentially affect multiple aging pathways. Then, they are then tested in living organisms using the C. elegans CelegAge™ system.

Rejuvenate suggests that using established drugs with proven safety for humans will help them lower development risks and time.

They use existing drugs, but they state they “secure strong patent protection, both composition and medical applications & formulation.”

Drug candidate RJx-01

Rejuvenate’s main candidate is RJx-01 is a combination of two drugs. One is galantamine, which is approved for Alzheimer’s. The other is metformin, used for diabetes.

RJx-01 is being developed to treat sarcopenia. Sarcopenia is the age-related loss of muscle mass or strength. This condition can happen even in people who do resistance exercise.

Putting RJx-01 to the test

In August 2023, scientists linked to Rejuvenate found that treating C. elegans worms with RJx-01 increased lifespan. This combination worked better than either drug alone. It also improved movement and pharyngeal pumping in adult worms. The results were inconsistently better than using each drug by itself.

RJx-01 also improved muscle fiber organization, although results for monotherapy with constituent drugs were not reported.

Animals started treatment at the late L4 larval stage and were tested on day seven as adults. C. elegans live for 2-3 weeks. Therefore, we cannot be sure if these results apply to treatments starting in middle age or early senior years.

The investigators treated physiologically-aged wild-type mice with RJx-01 for eighteen weeks. RJx-01 improved aging-like deficits in running time, muscle weight, and muscle size.

It also helped denervated muscle fibers, increased muscle strength, and reduced systemic inflammation in Opa1-knockout mice. These mice, which lack Opa1, show sarcopenia-like issues that usually appear in young adulthood.

These improvements were consistently superior to those of the constituent drugs alone.

The treatment did not affect food intake, body weight, muscle mass, mean fiber size, fiber size distribution, or fiber type. However it did increase running time, grip strength, sarcomere structure, and muscle mitochondrial morphology. It also decreased muscle fiber denervation by 15%.

RJx-01 in human trials

In October 2023, Rejuvenate announced positive results in a Phase Ib trial of RJx-01. The trial involved 42 male participants aged 65 to 75 with induced muscle atrophy. This was induced by spending two weeks with one leg immobilized in a cast.

This was followed by observation for an additional four weeks after removing the cast. Lastly, a muscular strength rehabilitation program was provided for participants.

The drug was said to be generally safe and well-tolerated with no reported treatment-related severe adverse events. Additionally, the company stated that the drug had exhibited excellent bioavailability.

In February 2024, Rejuvenate announced the functional outcome results.

The company said that people who received RJx-01 showed better muscle strength recovery than those who got a placebo. This was measured using isometric dynamometry, which checks grip strength with a handheld device. They also looked at leg acceleration with isokinetic dynamometry. Fatigue resistance was measured by watching muscle performance during leg exercises.

At the time, they announced they were “actively exploring partnership opportunities to investigate RJx-01 in combination with GLP-1 drugs.”

Phase II clinical trial for RJx-01

October 2024 saw an important partnership had been made. This partnership included the University of Leicester, National Institute for Health and Care Research, and Leicester Biomedical Research Centre. The partnership launched a Phase II trial of RJx-01 in participants with chronic obstructive pulmonary disease-related sarcopenia.

The trial is enabled by multimillion-dollar funding from the Dynamic Resilience program. This is co-funded by Wellcome Leap and Temasek Trust.

The trial will primarily assess the safety and tolerability of RJx-01 in 130 older people. These individuals have been hospitalized due to a severe worsening of COPD. The trial will also look at how RJx-01 affects physical function, muscle strength, and fatigue. In May 2025, Rejuvenate announced that it had dosed the first patient in this Phase II trial.

A second phase II clinical trial

Rejuvenate’s platform diagram indicates that it is in Phase II for a second, unnamed indication. However, the company has not reported any other trials beyond that.

Speculatively, this may relate to a February 2024 announcement. They stated they were “actively exploring partnership opportunities to investigate RJx-01 in combination with GLP-1 drugs,”. This highlights their potential use in Type II diabetes.

Other drug candidates

Rejuvenate’s platform diagram indicates that it has four additional candidates under development. These are RJx-02 in preclinical development, and RJx-03 through RJx-05 in discovery.