New experimental drug to transform arthritis treatment
LONDON: A drug that “spring cleans” joints by mopping up old cells could transform arthritis treatment.
The experimental drug, called UBX0101, is injected into major joints such as the knees or hips affected by osteoarthritis. Once inside, it destroys “senescent” cells. These are formerly healthy cells which have stopped dividing and now accumulate in the joints.
Recent research suggests senescent cells may contribute to painful conditions such as osteoarthritis by secreting chemicals that increase inflammation.
Early results suggest the revolutionary new drug not only stops joint damage in its tracks by wiping out many of these harmful cells but even allows cartilage – the body’s in-built shock absorber which gets broken down in osteoarthritis – to renew itself.
As the body ages, major joints such as the hips, knees and wrists suffer wear and tear. But other risk factors include being overweight, a family history of the condition and sports injuries.
Cartilage soaks up the impact from walking, running or lifting, so bones do not rub together. But in osteoarthritis, the cartilage starts to break down and as bones come into contact, the friction makes joints swollen and painful. There are no drugs to cure it and many patients rely on anti-inflammatory painkillers.
While these help, they can damage the stomach if used for long periods. Severe cases may be treated with steroid injections.
The new drug is based on a relatively recent theory that inflammation caused by senescent cells may contribute to a range of illnesses, including osteoarthritis and heart problems. Cells continually divide at a steady rate. Rapid, uncontrolled division is one of the hallmarks of cancer. To combat this, cellular senescence is the body’s way of resisting tumour growth by acting as an emergency brake. Senescent cells no longer replicate but are still alive, floating in the bloodstream.
They also play a role in the repair of wounds by sending out signals for immune system cells to clean up and repair the damage. But scientists have found that, in knee joints and cartilage in particular, they are not cleared out properly after that initial trauma.
A team of scientists from Johns Hopkins University in Baltimore, US, studied mice with injuries to the anterior cruciate ligament – a common knee injury in humans which raises the risk of osteoarthritis. Two weeks after the injury, the mice had the drug injected into their knees.
The results, published in Nature Medicine, showed the number of senescent cells instantly halved and that the jab activated genes involved in cartilage repair.
Separate tests on human cartilage in the lab showed that, four days after exposure to the drug, levels of senescent cells in the cartilage plummeted and the cartilage showed signs of regrowing.
The firm behind the jab, Unity Biotechnology, based in California, hopes to start trials on humans next year.
Philip Conaghan, professor of musculoskeletal medicine at Leeds University, welcomed the drug. “This is conceptually really interesting. But we need major clinical trials before getting too excited.”
Meanwhile, scientists have found senescent cells play a part in liver diseases and have devised a treatment for this. Conditions such as fatty liver disease and cirrhosis (both cause the supple liver to stiffen and malfunction) occur even among the teetotal.
Scientists now believe this may be because as we age, the mitochondria, the cell “batteries” that normally generate energy, stop using up fat and store it instead.
The journal Nature Communications reports that killing senescent cells in the liver reduces fatty build up. Researchers hope to test the treatment on humans soon. – Daily Mail
‘This is conceptually really interesting’