Tag: biologic drug

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Abatacept may Hold Back Progression of Rheumatoid Arthritis

On By ModernMedia
Photo by Towfiqu barbhuiya

Results from a Phase 2b clinical trial, published in The Lancet, provides hope for arthritis sufferers after it was shown that the biologic drug abatacept reduces progression to this agonising chronic inflammatory disease.

Rheumatoid arthritis is an autoimmune condition that typically (but not always) starts in middle age, with joint pain, swelling and significant disability. Until now there is no cure or prevention.

Abatacept is currently used as an effective second or third line treatment for people living with established rheumatoid arthritis and is given by weekly injections at home or intravenously in hospital.

Researchers from King’s College London recruited 213 patients at high risk of the disease to understand whether a year-long treatment of the biologic drug could be used to prevent progression to rheumatoid arthritis.

They recruited men and women over the age of 18 with early symptoms such as joint pain but no joint swelling, and treated half with the drug and half with a placebo every week for a year. The study drug was then stopped, and study participants monitored for a further 12 months.

After twelve months of treatment, 6% of patients treated with abatacept had developed arthritis compared to 29% in the placebo arm. By 24 months, the differences were still significant, with a total of 25% progressing to rheumatoid arthritis in the abatacept arm compared to 37% in the placebo arm.

Secondary outcomes for the trial showed that abatacept was associated with improvements in pain scores, function and quality of life measurements, as well as lower scores of inflammation of the lining of joints detectable by ultrasound scan.

Professor Andrew Cope, Professor of Rheumatology from School of Immunology & Microbial Sciences, said: “This is the largest rheumatoid arthritis prevention trial to date and the first to show that a therapy licensed for use in treating established rheumatoid arthritis is also effective in preventing the onset of disease in people at risk.

“These initial results could be good news for people at risk of arthritis as we show that the drug not only prevents disease onset during the treatment phase but can also ease symptoms such as pain and fatigue. This is also promising news for the NHS as the disease affects people as they age and will become more expensive to treat with a growing aging population.”

Philip Day, a 35-year-old software engineer and founder of FootballMatcher from Eltham, was at high-risk for rheumatoid arthritis. A keen football player, Philip’s joint pain deterred him from playing and affected his day-to-day life. He was enrolled in the trial in 2018, at the age of the 30, and was prescribed abatacept.

He said: “The pain got so terrible I stopped going to football, and I got lazier and felt progressively worse physically and mentally. The pain was unpredictable, it would show up in my knees one day, my elbows the next, and then my wrists or even my neck. At the time, my wife and I wanted to have children and I realised my future was pretty bleak if the disease progressed. I’d always wanted to be the kind of dad that played football with his son and I knew the pain would stop me from realising that dream.

“Enrolling in the trial was a no-brainer; it was a ray of hope at a dark time. Within a few months I had no more aches or pains and five years on I’d say I’ve been cured. Now, I can play football with my three-year-old son and have a normal life.”

One year’s treatment with abatacept costs the NHS about £10 000 (ZAR 238 000) per patient. Side effects include upper respiratory tract infections, dizziness, nausea and diarrhoea, but these are generally mild.

Professor Cope added: “There are currently no drugs available that prevent this potentially crippling disease. Our next steps are to understand people at risk in more detail so that we can be absolutely sure that those at highest risk of developing rheumatoid arthritis receive the drug.”

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Categories : Antibiotics Diseases, Syndromes and ConditionsTags : Leave a comment

Experimental Biologic Drug Defeats MRSA in Early Lab Tests

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Methicillin-resistant Staphylococcus aureus (MRSA). Image by CDC on Unsplash

Researchers reported in Cell Host & Microbe that early tests of a bioengineered drug candidate were successful in countering Staphylococcus aureus, a bacteria particularly dangerous to hospitalised patients. 

Experiments demonstrated that SM1B74, an antibacterial biologic agent, was superior to a standard antibiotic drug at treating mice infected with S. aureus, including its treatment-resistant form known as MRSA.

The researchers tested mAbtyrins, a combination molecule based on an engineered version of a human monoclonal antibody (mAb), a protein that clings to and marks S. aureus for uptake and destruction by immune cells. Attached to the mAb are centyrins, small proteins that prevent these bacteria from boring holes into the human immune cells in which they hide. As the invaders multiply, these cells die and burst, eliminating their threat to the bacteria.

Together, the experimental treatment targets ten disease-causing mechanisms employed by S. aureus, but without killing it, say the study authors. This approach promises to address antibiotic resistance, say the researchers, where antibiotics kill vulnerable strains first, only to make more space for others that happen to be less vulnerable until the drugs no longer work.

“To our knowledge, this is the first report showing that mAbtyrins can drastically reduce the populations of this pathogen in cell studies, and in live mice infected with drug-resistant strains so common in hospitals,” said lead study author Victor Torres, PhD, the C.V. Starr Professor of Microbiology and director of the NYU Langone Health Antimicrobial-Resistant Pathogen Program.”Our goal was to design a biologic that works against S. aureus inside and outside of cells, while also taking away the weapons it uses to evade the immune system.”

Inside Out

The new study is the culmination of a five-year research partnership between scientists at NYU Grossman School of Medicine and Janssen to address the unique nature of S. aureus.

The NYU Langone team together with Janssen researchers, published in 2019 a study that found that centyrins interfere with the action of potent toxins used by S. aureus to bore into immune cells. They used a molecular biology technique to make changes in a single parental centyrin, instantly creating a trillion slightly different versions of it via automation. Out of this “library,” careful screening revealed a small set of centyrins that cling more tightly to the toxins blocking their function.

Building on this work, the team fused the centyrins to a mAb originally taken from a patient recovering from S. aureus infection. Already primed by its encounter with the bacteria, the mAb could label the bacterial cells such that they are pulled into bacteria-destroying pockets inside of roving immune cells called phagocytes. That is unless the same toxins that enable S. aureus to drill into immune cells from the outside let it drill out of the pockets to invade from the inside.

In a “marvel of bioengineering,” part of the team’s mAbtyrin serves as the passport recognised by immune cells, which then engulf the entire, attached mAbtyrin, along with its centyrins, and fold it into the pockets along with bacteria. Once inside, the centyrins block the bacterial toxins there. This, say the authors, sets their effort apart from antibody combinations that target the toxins only outside of cells.

The team made several additional changes to their mAbtyrin that defeat S. aureus by, for instance, activating chain reactions that amplify the immune response, as well by preventing certain bacterial enzymes from cutting up antibodies and others from gumming up their action.

The researchers tracked the growth of S. aureus strains commonly occurring in US communities in the presence of primary human immune cells (phagocytes). Bacterial populations grew almost normally in the presence of the parental antibody, slightly less well in the presence of the team’s engineered mAb, and half as fast when the mAbtyrin was used.

In another test, 98% of mice treated with a control mAb (no centyrins) developed bacteria-filled sores on their kidneys when infected with a deadly strain of S. aureus, while only 38% of mice did so when treated with the mAbtyrin. Further, when these tissues were removed and colonies of bacteria in them counted, the mice treated with the mAbtyrin had one hundred times (two logs) fewer bacterial cells than those treated with a control mAb.

Finally, the combination of small doses of the antibiotic vancomycin with the mAbtyrin in mice significantly improved the efficacy of the mAbtyrin, resulting in maximum reduction of bacterial loads in the kidneys and greater than 70% protection from kidney lesions.

“It is incredibly important,” said Torres, “that we find new ways to boost the action of vancomycin, a last line of defence against MRSA.”

Source: NYU Langone Health / NYU Grossman School of Medicine