An experimental drug being developed for a serious lung disease may also help slow the biological aging process, according to researchers. Patients taking rentosertib showed changes in blood proteins that made them appear biologically younger in several tests.

Rentosertib was developed by Insilico Medicine in Massachusetts and is intended to treat idiopathic pulmonary fibrosis, or IPF. The serious disease causes scarring in the lungs.

The experimental drug was discovered with the help of artificial intelligence. In a small clinical study, its effects on blood proteins produced an unexpected result beyond its potential role in treating the disease.

Several tests estimated that patients were biologically about three to four years younger after treatment. In one case, a patient appeared up to six years younger based on the observed protein patterns.

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"There is a promising trend in age reversal in addition to treating the disease, and it came as a bonus for disease treatment," first author Alex Zhavoronkov, PhD, founder and co CEO of Insilico Medicine, told Fox News Digital.

Zhavoronkov said the findings were based on validated aging clocks used to predict biological age. "It basically means that you are predicted to be younger using a validated set of aging clocks. We don’t know what that means yet."

The results were published in Nature Biotechnology and presented Monday at the Nature conference at Sorbonne University in Paris. However, the researchers cautioned that the findings do not prove rentosertib can reverse aging or help people live longer.

"It’s early days," Zhavoronkov noted. "The drug is still investigational."

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Six different aging tests showed the same general pattern, with patients who received rentosertib scoring biologically younger than those given a placebo. The strongest effect appeared after four weeks among patients taking 30 mg of the drug twice a day.

Researchers also compared the findings with data from more than 55,000 people in the UK Biobank. They found that rentosertib changed several blood proteins in the opposite direction from what is normally observed with aging.

The study also identified signs that the drug may affect aging at the cellular level. Rentosertib changed processes involved in how cells function and respond to damage, according to the findings.

Zhavoronkov said Insilico Medicine uses artificial intelligence to search for what he calls "molecular criminals," meaning biological targets that may contribute to aging and disease. Researchers from Harvard Medical School, Stanford University, the Broad Institute, RWTH Aachen University, Peking University and Westlake University also participated in the study.

Still, Zhavoronkov emphasized that the research remains preliminary. "This is a pilot," he said. "It is early [and] exploratory."

The study included only 42 patients who were analyzed over a 12 week period. Because all participants had IPF, the disease itself could have affected many of the same proteins used by researchers to measure biological aging.

Therefore, it is possible that improvements in the participants’ lung disease were related to the observed blood protein changes. The findings were based only on proteins in the blood and do not support using rentosertib as an anti aging treatment.

The researchers acknowledged that the results do not prove the drug slows aging, keeps people healthier for longer or extends their lives. Larger and longer trials involving healthy older adults and populations without IPF are needed to determine whether the drug has anti aging effects and whether those effects could produce better health.

Dr. Carol Ann Satler, senior vice president of clinical development for Insilico Medicine, said the risks and side effects associated with rentosertib were "manageable." The most common potential side effects were mild diarrhea, slightly lower potassium levels in the blood and temporary increases in liver enzymes.

"Once you stop the drug, essentially, they return to normal," Satler told Fox News Digital. She said researchers plan to adjust doses based on the side effect profile in the next trial so participants can remain on the drug longer.

Rentosertib has progressed into a year long phase 3 study involving more than 300 patients in China, according to Insilico Medicine. Meanwhile, Zhavoronkov said the early findings strengthened his confidence in pursuing drugs that could target both age related diseases and aging itself.

"Everybody agrees that living longer should be a fundamental human right for everyone," he said.