A “vaccine” which harnesses the body’s own immune system to fight prostate cancer has been approved for use by US drug regulators.
Provenge – which is designed to be used in men with advanced disease – is the first of its kind to be accepted by the Food and Drug Administration.
Each dose has to be individually tailored and it is an expensive treatment at $93,000 per patient.
It will add to, rather than replace, existing treatments, said experts.
Doctors have been working on therapies that prompt the immune system to fight tumours for decades.
Potential success stories include an experimental vaccine for melanoma which is in the late stages of development.
This latest therapy is made by collecting special blood cells from each patient that help the immune system recognise cancer as a threat.
These are then mixed with a protein found on most prostate cancer cells and a substance which kick-starts the immune response.
The drug is not a “cure” but is used in advanced prostate cancer that has spread to other sites in the body and is no longer responding to standard hormone treatment.
Clinical trials showed that the treatment extended the lives of patients by four months.
This compares with an average of three months with chemotherapy.
Dr Phil Kantoff, an oncologist at the Dana-Farber Cancer Institute who helped run the studies of Provenge said: “The big news here is that this is the first immunotherapy to win approval, and I suspect within five to ten years immunotherapies will be a big part of cancer therapy in general.”
Prostate cancer accounts for about 12% of male deaths from cancer in the UK and is the second most common cause of cancer death in men.
In older men aged 85 and over, the disease is the most common cause of all deaths from cancer.
John Neate, chief executive of The Prostate Cancer Charity, said: “The news that this type of immunotherapy may offer additional survival benefit is promising.”
But he added: “There are still questions to answer, even if the treatment fulfils its early promise.
“At present, we believe there are currently no laboratories in Europe equipped to undertake this treatment.
“Furthermore, this treatment is not currently approved in the UK and it will still be some years before doctors know enough about its long term effectiveness and side effects to be confident about its potential place in the armoury against advanced prostate cancer.”
Dr Chris Parker, Cancer Research UK’s prostate cancer expert said: “We hope this approval will open new avenues of research into using a patient’s own immune system to treat cancer.”
Archive for May 2nd, 2010
Posted by Xeno on May 2, 2010
Posted by Xeno on May 2, 2010
Hydrogen would command a key role in future renewable energy technologies, experts agree, if a relatively cheap, efficient and carbon-neutral means of producing it can be developed. An important step towards this elusive goal has been taken by a team of researchers with the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley. The team has discovered an inexpensive metal catalyst that can effectively generate hydrogen gas from water.
“Our new proton reduction catalyst is based on a molybdenum-oxo metal complex that is about 70 times cheaper than platinum, today’s most widely used metal catalyst for splitting the water molecule,” said Hemamala Karunadasa, one of the co-discoverers of this complex. “In addition, our catalyst does not require organic additives, and can operate in neutral water, even if it is dirty, and can operate in sea water, the most abundant source of hydrogen on earth and a natural electrolyte. These qualities make our catalyst ideal for renewable energy and sustainable chemistry.”
Karunadasa holds joint appointments with Berkeley Lab’s Chemical Sciences Division and UC Berkeley’s Chemistry Department. She is the lead author of a paper describing this work that appears in the April 29, 2010 issue of the journal Nature, titled “A molecular molybdenum-oxo catalyst for generating hydrogen from water.” Co-authors of this paper were Christopher Chang and Jeffrey Long, who also hold joint appointments with Berkeley Lab and UC Berkeley. Chang, in addition, is also an investigator with the Howard Hughes Medical Institute (HHMI).
Hydrogen gas, whether combusted or used in fuel cells to generate electricity, emits only water vapor as an exhaust product, which is why this nation would already be rolling towards a hydrogen economy if only there were hydrogen wells to tap. However, hydrogen gas does not occur naturally and has to be produced. Most of the hydrogen gas in the United States today comes from natural gas, a fossil fuel. While inexpensive, this technique adds huge volumes of carbon emissions to the atmosphere. Hydrogen can also be produced through the electrolysis of water – using electricity to split molecules of water into molecules of hydrogen and oxygen. This is an environmentally clean and sustainable method of production – especially if the electricity is generated via a renewable technology such as solar or wind – but requires a water-splitting catalyst.
Nature has developed extremely efficient water-splitting enzymes – called hydrogenases – for use by plants during photosynthesis, however, these enzymes are highly unstable and easily deactivated when removed from their native environment. Human activities demand a stable metal catalyst that can operate under non-biological settings.
Metal catalysts are commercially available, but they are low valence precious metals whose high costs make their widespread use prohibitive. For example, platinum, the best of them, costs some $2,000 an ounce.
“The basic scientific challenge has been to create earth-abundant molecular systems that produce hydrogen from water with high catalytic activity and stability,” Chang says. “We believe our discovery of a molecular molybdenum-oxo catalyst for generating hydrogen from water without the use of additional acids or organic co-solvents establishes a new chemical paradigm for creating reduction catalysts that are highly active and robust in aqueous media.”
The molybdenum-oxo complex that Karunadasa, Chang and Long discovered is a high valence metal with the chemical name of (PY5Me2)Mo-oxo. In their studies, the research team found that this complex catalyzes the generation of hydrogen from neutral buffered water or even sea water with a turnover frequency of 2.4 moles of hydrogen per mole of catalyst per second.
Long says, “This metal-oxo complex represents a distinct molecular motif for reduction catalysis that has high activity and stability in water. We are now focused on modifying the PY5Me ligand portion of the complex and investigating other metal complexes based on similar ligand platforms to further facilitate electrical charge-driven as well as light-driven catalytic processes. Our particular emphasis is on chemistry relevant to sustainable energy cycles.” …
Posted by Xeno on May 2, 2010
A bacterial pathogen can communicate with yeast to block the development of drug-resistant yeast infections, say Irish scientists writing in the May issue of Microbiology. The research could be a step towards new strategies to prevent hospital-acquired infections associated with medical implants.Researchers from University College Cork in Ireland studied the interaction between the bacterium Pseudomonas aeruginosa, which is often associated with severe burns, and the yeast Candida albicans, which can grow on plastic surfaces such as catheters. Both microbes are very common and although they are normally harmless to healthy individuals, they can cause disease in immunocompromised people.
The team discovered that molecules produced by P. aeruginosa bacteria were able to hinder the development of C. albicans ‘biofilms’ on silicone, when the yeast cells clump together on the surface of the plastic. Interestingly, the interaction between the two organisms did not depend on the well-studied bacterial communication system called Quorum Sensing, indicating that a novel signalling mechanism was at play.
C. albicans is the most common hospital-acquired fungal infection and can cause illness by sticking to and colonising plastic surfaces implanted in the body such as catheters, cardiac devices or prosthetic joints. This biofilm formation is a key aspect of C. albicans infection and is problematic as biofilms are often resistant to the antibiotics used to treat them. Dr John Morrissey, who led the team of researchers, said, “Candida albicans can cause very serious deep infections in susceptible patients and it is often found in biofilm form. It is therefore important to understand the biofilm process and how it might be controlled.”
Dr Morrissey believes his work may lead to significant clinical benefits. “If we can exploit the same inhibitory strategy that the bacterium P. aeruginosa uses, then we might be able to design drugs that can be used as antimicrobials to disperse yeast biofilms after they form, or as additives onto plastics to prevent biofilm formation on medical implants,” he said. “The next steps are to identify the chemical that the bacterium produces and to find out what its target in the yeast is. We can then see whether this will be a feasible lead for the development of new drugs for clinical application.”