Erectile dysfunction drug could enhance delivery of herceptin to brain tumours

A drug currently approved to treat erectile dysfunction could significantly improve the delivery of the anti-cancer drug Herceptin to certain hard-to-treat brain tumours, according to a new study at Cedars-Sinai’s Maxine Dunitz Neurosurgical Institute.

The research could help doctors improve treatments for lung and breast cancers that have metastasized to the brain.

Even if a cancer is susceptible to drugs, these drugs must penetrate the “blood-brain barrier” if they’re to treat cancer that’s metastasised to the brain.

“Mother Nature created this barrier to protect our brains from dangerous substances, but here we need to get through the barrier to deliver the drugs, and that’s a problem,” says study author Dr. Julia Y. Ljubimova.

Dr. Keith Black, lead research scientist on this project, has studied the blood-brain barrier for about two decades.

Research conducted by his team found that the erectile dysfunction drugs sildenafil (Viagra) and vardenafil (Levitra), which inhibit the enzyme phosphodiesterase 5 (PDE5), could increase the permeability of the blood-brain tumour barrier and boost the effectiveness of the chemotherapy drug doxorubicin.

“No matter how effective against cancer a chemotherapeutic agent may be, it can have little impact on brain tumours if it cannot cross the blood-brain tumour barrier. As we find new drugs that are able to target these tumour cells, it is imperative that we develop better ways to enable the medications to reach their targets,” he said.

In the current study, the researchers examined whether PDE5 inhibitors might also increase the blood-brain tumour barrier’s permeability to Herceptin- a monoclonal antibody used to treat lung and breast tumours that are positive for HER2/neu.

Herceptin is a large molecule that does not easily cross the blood-brain tumour barrier, a limitation that severely reduces its effectiveness at treating brain metastases.

The researchers first measured vardenafil’s effects on the permeability of the blood-brain tumour barrier.

Using a mouse model, the scientists showed that vardenafil led to a two-fold increase in the amount of Herceptin that reached brain metastases of lung and breast cancers.

Next, they examined whether this increase in blood-brain barrier permeability improved Herceptin’s effectiveness at treating these brain metastases by giving mice vardenafil in tandem with Herceptin.

The results showed that the combination of vardenafil plus Herceptin boosted mean survival by 20 percent, compared to Herceptin alone (7218 days versus 599 days).

The study was published in the journal PLoS ONE.

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ImmunoCellular Therapeutics Reports Additional Data from Promising Brain Cancer Clinical Trial

ImmunoCellular Therapeutics, Ltd. , a biotechnology company, presented promising clinical data from a Phase I trial evaluating ICT-107, the company's dendritic cell-based cancer vaccine product candidate for the treatment of glioblastoma. These data were reported at the American Society of Clinical Oncology Meeting in Orlando, Florida (Abstract #2032), and supplement the preliminary data from the completed clinical trial that the Company reported in December 2008.

The Phase I clinical trial of ICT-107 was conducted to evaluate the safety and tolerability of the cancer vaccine in patients with glioblastoma, the most common and malignant type of brain cancer. The trial enrolled 19 patients—16 with newly-diagnosed and three with recurrent disease—and was conducted at Cedars-Sinai Medical Center.

Seven of the 16 newly-diagnosed patients demonstrated stable disease with median progression-free survival of 64 weeks, and three of these seven patients have progression-free survival of over two years. The median progression-free survival time of newly-diagnosed glioblastoma patients is historically 30 weeks. ICT-107 was well tolerated, and no significant adverse events were reported. Nine of the 16 newly-diagnosed patients had progressive disease with a median progression-free survival of 39 weeks and median survival of 56 weeks. The three patients enrolled who had recurrent disease progressed in their disease but still exhibited extended survival times of 34, 47 and 59 weeks.

Fifteen patients in the trial were evaluated for immune responses, and six of them had a significant immune response to at least one tumor-associated antigen. Patients demonstrating an immune response are exhibiting a trend toward longer overall survival. ICT-107 was well tolerated in the study, with no grade 3/4 adverse events and only mild side effects, including grade 1 fatigue, skin rash and pruritis, which were transient in nature.

“The survival benefit that we are seeing in this trial of ICT-107 is exciting. As a physician who regularly treats glioblastoma patients, having access to an immunotherapy like ICT-107, which may someday have the ability to provide patients with an extended survival and a relatively innocuous side effect profile would be a great improvement over what we currently have to offer,” stated Surasak Phuphanich, M.D., the principal investigator of the trial and a senior author of the ASCO presentation. “With a historical median progression-free survival time of 6.9 months in glioblastoma, we are encouraged to see a median progression-free survival time of 14.2 months (57.5 weeks) in this newly-diagnosed glioblastoma (16 patients) population, and furthermore, it is exciting to see the correlation between immune response and survival given that the goal of ICT-107 is to elicit a cancer-specific immune response.”

“While the data from ICT-107 are encouraging, our top priority is to advance our 'off-the-shelf' cancer stem cell vaccine product candidate, ICT-121, into the clinic. IMUC is expecting to file an Investigational New Drug (IND) application for ICT-121 in the fourth quarter of this year. ICT-121, which may have applicability to multiple types of cancer, will target glioblastoma in the initial Phase I trial,” stated Manish Singh, Ph.D. “With the great unmet need represented by glioblastoma across all age groups, we are hopeful that an immunotherapy, such as ICT-121 or ICT-107, may someday offer patients a more effective and safer treatment alternative.”

About ICT-107

ICT-107 is IMUC's patient-specific therapeutic cancer vaccine product candidate that consists of dendritic cells—immune system cells responsible for presenting antigens (immune system targets) to the immune system—which are obtained from the patient's blood and “programmed” with tumor antigens which in turn provide a target for the immune system. The immune system should then be armed to seek and destroy any remaining glioblastoma cells. Patients in the Phase I trial received three intradermal injections of ICT-107 at two-week intervals.

About Glioblastoma

The high rate of mortality of patients diagnosed with brain cancers and in particular with glioblastoma multiforme (the most lethal and devastating form) is driving the scientific community to discover and develop improved treatments that could increase the survival time and enhance the quality of life of patients. Of the approximately 19,000 cases of malignant brain and spinal cord tumors that are diagnosed each year in the United States, there currently is no satisfactory treatment, and the two-year survival rates are only in the range of 26 percent. Neither surgery, radiation nor anti-cancer drugs, the standard treatment modalities, have shown to date any prospect of meaningful extension of patients' lives.

About ImmunoCellular Therapeutics, Ltd.

IMUC is a Los Angeles-based clinical-stage company that is developing immune based therapies for the treatment of brain and other cancers. The company's “off the shelf” therapeutic vaccine product candidate targeting cancer stem cells for multiple cancer indications is targeted by IMUC to enter clinical trials during the fourth quarter of 2009. IMUC has recently completed a Phase I trial of its dendritic cell-based clinical product candidate for glioblastoma. IMUC is in pre-clinical development of a monoclonal antibody product candidate for the treatment of small cell lung cancer and pancreatic cancer, and is also evaluating its platform technology for monoclonal antibody discovery using differential immunization for diagnosing and treating multiple types of cancer. To learn more about IMUC, please visit www.imuc.com.

Forward-Looking Statements

This press release contains certain forward-looking statements that are subject to a number of risks and uncertainties, including without limitation, the risks associated with obtaining FDA clearance to commence clinical trials of the cancer stem cell vaccine on a timely basis or at all; the risks associated with adhering to projected preclinical or clinical timelines and the uncertainties of outcomes of development work for product candidates, including those based on destroying cancer stem cells as a potentially safe and effective treatment for various cancers; the risk that future trials of the dendritic cell-based vaccine product candidate, if any, do not confirm the safety and efficacy data generated in the Phase I trial; the need to satisfy performance milestones to maintain the vaccine technology licenses with Cedars-Sinai; the risks associated with obtaining a patent that provides commercially significant protection for each of the cancer vaccine product candidates and the need to obtain licenses from third parties before commercializing the dendritic cell-based vaccine; and the need for substantial additional capital to fund development of product candidates beyond their initial clinical or pre-clinical stages. Additional risks and uncertainties are described in IMUC's most recently filed SEC documents, such as its most recent annual report on Form 10-K, all quarterly reports on Form 10-Q and any current reports on Form 8-K. IMUC undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Source : www.drugs.com

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FDA approves new brain cancer drug

South San Francisco-based Genentech, Inc., now owned by Roche, announced Tuesday that the FDA has granted accelerated approval of Avastin for people with glioblastoma, one of the most aggressive forms of brain cancer.

While it is still incurable, previously glioblastoma was considered untreatable.

"People with this type of brain cancer have had no new treatments in more than a decade," said Timothy Cloughesy, an oncologist at the University of California, Los Angeles. "After so many years with little progress in this field, Avastin was associated with a durable tumor response and doctors now have a new medicine to offer patients."

Avastin received accelerated approval just 35 days after an advisory panel's unanimous recommendation. Currently, only one out of six patients treated for glioblastoma sees no progression of the disease after six months.

About 10,000 patients currently suffer from glioblastoma, and about 2,900 are eligible for therapy with Avastin, according to a Genentech spokeswoman.

Avastin is one of Genentech's best selling drugs, and is already approved to treat other cancers including lung, colon, and breast cancer.

Source : www.mercurynews.com

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