Source: Medical News Papers, Inc.
By Lynne Jeter
Despite tremendous advances in recent years in the field of antiretroviral (ARV) therapy, the Human Immunodeficiency Virus’s (HIV) ability to mutate and develop resistance to these drugs poses a significant problem for treatments that are already in use and those in the pipeline.
The effective treatment of HIV-infected patients is also compromised by the toxicity of approved regimens, conferred resistance, and cross-resistance. These developments are of particular concern in developing countries, where 95 percent of all cases of HIV are diagnosed.
Las Vegas-based Samaritan Pharmaceuticals’ HIV oral entry inhibitor, SP-01A, currently in development, represents a significant step forward in HIV treatment. Used with any existing anti-retroviral drug, SP-01A creates a firewall around healthy cells that prevents HIV entry.
“At present, a number of drugs on the market do an incredible job extending life expectancies of patients with HIV,” explained Dr. Janet Greeson, CEO of Samaritan Pharmaceuticals, Inc. “However, these drugs do not address myriad serious side effects,” which kidney stones; nausea; vomiting; diarrhea; increased cholesterol, triglycerides, and glucose; headaches; weakness; blurred vision; dizziness; rashes; low platelets; hair loss; and anemia.
Unlike currently approved antiretroviral therapies, SP-01A, the only oral entry inhibitor in its class, conditions the cell membrane as opposed to targeting the virus or its receptors directly.
In a 30-patient, 8-week study, SP-01A demonstrated proof of concept with significance in two crucial areas: a viral log drop of 1.32 (virus undetectable, with no adverse events), and improved quality of life. In fact, SP-01A was the only drug of its kind in clinical trials to demonstrate improved patient quality of life, according to Whalen Scale indices.
“HIV patients’ QOL (quality of life) is usually based on their viral load and CD4 parameters and side effects from their ARVs,” Greeson pointed out. “Patients with high viral loads and low CD4 counts usually experience opportunistic infections where HIV weakens the immune system, making the body more susceptible to other infections, such as fungal, bacterial, viral, parasitic infections and pneumonias. Therefore, a new HIV treatment that lowers viral load, increases CD4 counts, and adds no addition side-effect burden, where the majority of current antiretroviral treatments do add side effects, would be of great benefit to the improvement of an HIV patient’s QOL.”
New HIV drugs should develop a new way to block entry of the HIV virus into the CD4 cell while not adding any safety burden, noted Greeson.
“One way to accomplish this is to create a firewall in the CD4 cell by modifying the cell content to resist HIV viral entry and enhance the effect of current HIV therapies,” she said. “Currently, all the drugs on the market attack the virus at different mechanisms of action after cell entry. The virus is extremely tricky and finds new ways to counter punch these drugs. By creating a firewall to prevent cell entry, you wouldn’t even have to enter the ring to battle HIV.”
In addition to SP-01A, Samaritan has SP-10 and SP-03, which are new molecules that have similar mechanisms of action in preventing viral entry into healthy cells.
“It’s possible that in the near future, a drug will be developed that will block the entry of the HIV virus in to CD4 cells throughout the body, including crossing the BBB (blood brain barrier) allowing for current and future HIV treatments to kill the circulating virus, thus allowing the body’s immune system to respond and tackle HIV and not be overwhelmed,” said Greeson. “My vision is that a person could control HIV (so that) no new virus is able to enter and the killer HIV treatments would be able to knock out the virus so a person might be virus free as long as they were taking the treatment -- similar to insulin with diabetes. In addition, one could envision a ‘day-after cocktail,’ which could be used to contain and kill the virus before it has a chance to take hold and over come the immune response.”
SP-01A has been used concomitantly with most HIV antiretrovirals in Phase I/II clinical studies and found to enhance the effect of the HIV drugs used significantly, “a mean 1.3 log10 decrease in viral load,” detailed Greeson. “Upon completion of Phase II/III clinical studies, SP-01A would be submitted for FDA approval. Therefore, we target commercialization in about two to three years.”
Samaritan is collaborating with Pharmaplaz to develop and commercialize SP-01A.
Last year, Samaritan was honored with the 2006 North American Frost & Sullivan Award Technology Innovation Award in the field of HIV drug development in recognition of the company’s effort in developing this antiviral therapy-based drug.
About Samaritan Pharmaceuticals
Samaritan Pharmaceuticals: "Transforming Today's Science Into Tomorrow's Cures...''
Samaritan Pharmaceuticals (samaritanpharma.com) is an entrepreneurial biopharmaceutical company committed to bringing innovative life-saving drugs to suffering patients.
The company disclaims any information created by an outside party and endorses only information communicated by its press releases, filings, and website. This news release contains forward-looking statements that reflect management's current beliefs about the potential for its drug candidates, science, and technology. However, as with any biopharmaceutical under development, there are significant risks and uncertainties in the process of development and regulatory review. There are no guarantees that products will prove to be commercially successful. For additional information about the factors that affect the company's business, please read the company's latest Form 10-Q filed November 19, 2007. The company undertakes no duty to update forward-looking statements.
The Investor Relations Group
Adam Holdsworth / Erica Ruderman / Rachel Colgate