Tysabri approved for Crohn's in USA

Bloomberg.com reports that the Food and Drug Administration has approved Tysabri (Natalizumab) for treating Crohn's disease in some cases. Tysabri is already being used for the treatment of Multiple Sclerosis, but was briefly withdrawn after some serious side effects. European regulators refused to approve it for Crohn's disease.

Boston.com has further information:

European regulators recently rejected a similar request to use the drug as a Crohn's treatment, arguing the risk of infection outweighed the relatively modest benefit of Tysabri.

Biogen Idec temporarily shelved the drug three years ago after it was linked to a rare brain disease. The company says there have not been any additional cases of the disease since sales resumed in 2006, with new guidance on how it should be used. But some doctors remain wary of the treatment, even though it has been shown to be highly effective in some patients.

The Wikipedia has more comprehensive background on the drug.

Suspicion falls on milk

Researchers at The University of Liverpool have got one step closer to linking Crohn's disease to milk consumption.

The team found that a bacterium called Mycobacterium paratuberculosis releases a molecule that prevents a type of white blood cell from killing E.coli bacteria found in the body. E.coli is known to be present within Crohn’s disease tissue in increased numbers.

It is thought that the Mycobacteria make their way into the body’s system via cows’ milk and other dairy products. In cattle it can cause an illness called Johne's disease - a wasting, diarrhoeal condition. Until now, however, it has been unclear how this bacterium could trigger intestinal inflammation in humans.

The Daily Mail has further details, including a comment from the dairy industry:

The Dairy Council, which speaks for milk producers, said a number of studies had failed to show a causal link between MAP in milk and Crohn's.

Its director, Dr Judith Bryans, said: "While the findings of the study are interesting, it is important to stress that not all Crohn's patients have MAP in their intestines.

"This would suggest that there are additional factors which may cause Crohn's disease."

She added: "There is no need for anyone to alter their consumption of milk based on current scientific knowledge."

Wouldn't it be nice if most Crohn's was found to be caused by MAP in milk, and that it could be cured with a brief cause of antibiotics. I am certain we'll be hearing more on this subject during 2008.

Stem cells to reboot Crohn's?

There's some interesting research being done at the University of Nottingham into using stem cell therapy to "cure" Crohn's disease. Their trial hasn't started yet, but it is intriguing.

Crohn's sufferers are genetically predisposed to the disease, which is first triggered in their body when they come into contact with a particular environmental stimulus. Once this happens, the immune system responds — leading to symptoms that blight the lives of sufferers.

Stem cells hold a potential solution to this problem. As the body's 'master' cells, which can be directed to form any type of tissue, they will be extracted from patients and then re-established in their bone marrow to 're-boot' the immune system, taking it back to a state before Crohn's symptoms were triggered.

There is also a brief mention of their other current investigation into the use of hookworms to control mild Crohn's disease, but unfortunately they don't say whether the trial is going well.

Biologic in a pill

Can-Fite(pdf) have stated that they believe their new biologic medication CF101 will be effective in improving the symptoms of Crohn's sufferers.

Can-Fite reports that pre-clinical studies show that the A3 adenosine receptor, which is targeted by CF101, is over-expressed in bowel tissue and peripheral blood mononuclear cells derived from patients with Crohn's disease. These findings are in line with previous data showing the efficacy of CF101 as an anti-inflammatory agent in pre-clinical models of inflammatory bowel diseases.

The presence of this receptor on the surface of the affected cells of patients with Crohn’s disease strongly suggests that this patient population may benefit from CF101 which binds to the receptor and leads to apoptosis of the inflammatory cells. It should also be underlined that, similar to other indications under development, the drug exerts a differential effect on inflammatory normal cells.

All things being equal, if CF101 is as effective as infliximab (Remicade) and adalimumab (Humira), then being able to take it as a pill will offer a great benefit to patients compared to the injections required for the current biologics.

Crohn's comic

Artist Tom Humberstone has created an engaging personal account of the Crohn's experience in his comic Everything You Never Wanted to Know About Crohn's Disease. It's a great resource to explain the effects of Crohn's to family and friends, instead of the dry list of medical symptoms from most medical sites.

Better results from capsule endocopies

A small trial has found that capsule endoscopies after surgery are better tolerated and produce better results than regular colonscopies. This was reported in Gastrointestinal Endoscopy (full article for subscribers only), with more details freely viewable at Medpage Today.

Given that patients preferred the preparation and procedure surrounding swallowing a small camera, and that the results were significantly more accurate than with the traditional camera on the end of a flexible tube, I expect to see further progress on making this standard soon.

How do Tysabri and Cimzia work?

The Los Angeles Times has a good description of how two of the latest Crohn's medications operate:

Cimzia is also a TNF blocker, but unlike the others it contains only part of the antibody -- the portion that recognizes TNF. The rest of the antibody -- the part that can induce its own immune response -- is replaced with a compound called PEG.

This PEG tail stabilizes the drug, allowing it to stay in the patient's body much longer[...].

That means patients would only require treatment every other month, as opposed to every other week with Humira.

During inflammation, infection-fighting white blood cells of the immune system cruise through capillaries, searching for infection. When tissues are infected, they put out signals to slow down the blood cells and coax them to enter the tissue. [...]

Tysabri binds to those exit signs -- blocking them from recognition by the immune cells that are causing the Crohn's. So the white blood cells keep on moving, and the course of inflammation is stopped.

It'll be exciting to see how well these drugs operate on a wider variety of Crohn's patients, if and when they are approved.

Infliximab subsidised in Australia

The Sydney Morning Herald reports, as predicted, that Infliximab will be available on the Pharmaceutical Benefits Scheme (PBS) from October for the treatment of Crohn's disease. Prior to this patients would have to pay the thousands of dollars themselves, or be one of the lucky few paid for by a hospital.

Humira approved for Australia

The Daily Telegraph reports that Humira has been approved for the treatment of Crohn's disease in Australia. However, until it is listed on the Pharmaceutical Benefits Scheme (if it ever is), its cost of $16,000 per month will be prohibitive for many people.

Traditional Chinese medicine

From the unlikely source of a new player in pharmaceuticals, Asia's largest company Hutchison, comes news of an alternative to the usual Crohn's medicines. The Independent reports that initial trials of a compound found in traditional Chinese medicine have found it to be as effective as the more common treatments in Ulcerative Colitis, and is expected to be similarly effective in Crohn's. The story is in their business section, so it's a bit sparse on details, but it's definitely an area to keep an eye on. (Image from PoYang)