Nov11-4-1

News (Updated November 27, 2011)

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HIV trial scrapped after gel found to be ineffective

(AFP) – 26 November, 2011

WASHINGTON — In a major setback for AIDS prevention research, a clinical trial of a new vaginal gel supposed to reduce HIV infections has been suspended after studies showed it to be ineffective.

Researchers from the Microbicide Trials Network, set up by the US National Institutes of Health (NIH), expressed surprise at the outcome as a previous study on a gel containing the drug tenofovir had shown encouraging results.

Researchers are striving to produce a gel or a pill that protects women against HIV infection but still allows them to get pregnant so it can be used in sub-Saharan Africa and other places where condom use can be a problem.

A first trial by the Centre for the AIDS Programme of Research in South Africa (CAPRISA) showed reduced HIV infections in 39 percent of women treated with the tenofivir gel, and in 54 percent of those who used it regularly.

Those results, published in 2010, raised hopes that a new gel could slow the transmission of HIV/AIDS and finally provide women with a groundbreaking means of protecting themselves.

Observers had hoped VOICE (Vaginal and Oral Interventions to Control the Epidemic), a trial started in September 2009 and conducted with the help of 5,000 women in South Africa, Uganda and Zimbabwe, would back those findings.

An interim review of VOICE by an independent data and safety monitoring board, however, determined that the tenofovir gel was even less effective than a placebo. Part of the research has now been canceled.

Another area of the three-part trial, involving a tenofovir pill, was scrapped in September for similar reasons, but studies are ongoing on a third avenue using tenofovir and a booster drug.

"For now, the study will continue and we will work to complete the remaining visits for the women continuing in the study," researchers Sharon Hillier and Ian McGowan wrote.

"We are all eager to understand whether adherence, our daily dosing strategy, inflammation or other factors could explain the lack of oral and vaginal tenofovir effectiveness in VOICE, we will not likely have all of the assays completed until later next year."

Hillier said she was "surprised and disappointed" by the results, and the researchers said they must wait until the end of the remaining trial before a fuller analysis could be undertaken.

CAPRISA director Salim Abdool Karim, a site director in the VOICE trial, admitted to being gravely disappointed.

"These results were totally unexpected as there is good evidence from laboratory research, animal studies and human trials showing that tenofovir gel prevents HIV. However, science does not always produce the answer we hope for," he said.

"This is particularly pertinent when a drug's effectiveness is dependent on a complex combination of the biological activity of the drug and the human behavior influencing use of the drug as prescribed during the study.

"I look forward to seeing the complete results and, in particular, an analysis of whether the drug levels in the female genital tract provides any clues to the study's outcome."

Despite the setback, there have been other encouraging signs in the HIV/AIDS struggle in recent years.

In South Africa , whose population of 5.6 million HIV-infected people is the biggest in the world, the incidence rate fell by a third between 2001 and 2009, from 2.4 percent to 1.5 percent.

But the sub-Saharan African region continues to have the largest number of people infected with HIV.

In 2010, they made up some 68 percent or 22.9 million of all HIV-infected people.

Gilead to buy biotech Pharmasset for $11 billion

Nov 21 2011

By Lewis Krauskopf and Anand Basu

(Reuters) - Gilead Sciences Inc struck a deal to buy biotechnology company Pharmasset Inc for about $11 billion (7 billion pounds) in a huge bet to diversify its portfolio with new hepatitis C treatments.

Gilead , the world's largest maker of HIV drugs, will pay $137 per share for each Pharmasset share, an 89 percent premium to Pharmasset's Friday closing price.

Pharmasset has been one of the hottest biotech stocks in the last year based on the potential of its experimental hepatitis C medicines to create a treatment regimen for the liver disease without commercially manufactured interferons.

Interferons are proteins that help the body's immune system respond to viruses and other invaders, but they often cause flu-like side effects that lead many hepatitis C patients to stop or delay treatment.

Shares of Pharmasset rose 85 percent to $134.47 in morning trading. Shares of Gilead , which said the deal would reduce its earnings through 2014, fell nearly 11 percent to $35.56.

" Gilead is making a pretty smart acquisition here," said Brian Skorney, an analyst with Brean Murray, Carret & Co. "It's definitely a high-risk acquisition, but I think it could pay off in dividends for them."

Skorney said it was possible that another bidder could emerge, noting that Roche Holding AG has a partnership with Pharmasset. Bristol-Myers Squibb, Johnson & Johnson and Merck & Co also sell or are developing hepatitis medicines.

"Given the premium, Gilead is hoping to avoid another potential suitor coming to the table at a higher price," Skorney said.

Shares of Inhibitex Inc, which also is developing hepatitis C medicines, jumped 28 percent.

Untreated, hepatitis C can lead to cirrhosis, liver cancer and the need for a liver transplant. The disease infects an estimated 4 million Americans and 180 million people worldwide.

According to Gilead , more than 12 million people are infected with hepatitis C in major markets, but fewer than 200,000 are treated annually.

Vertex Pharmaceuticals Inc and Merck won approval this year for new hepatitis C medicines that hold the potential for far higher cure rates. However, both new drugs must be taken with interferon, and Vertex shares have dropped on expectations that new treatments, like Pharmasset's, could soon overtake them.

Vertex shares were down 2.5 percent after the Gilead-Pharmasset deal was announced.

ANTIVIRAL EXPERIENCE

Pharmasset has three hepatitis C medicines in clinical trials. Its lead candidate, PSI-7977, was recently advanced into two Phase III studies. Gilead said it expects PSI-7977 will be submitted for U.S. approval in the second half of 2013.

Gilead Chief Executive John Martin said on a call with analysts that Pharmasset's experimental drugs, combined with Gilead 's own hepatitis C portfolio, would allow the company to test multiple regimens that are oral and interferon-free.

In justifying the high premium, Gilead said PSI-7977 will be more valuable in its hands because it has the infrastructure in place to bring the product to more people faster than Pharmasset.

" Gilead has vast experience in antivirals and is currently a leader in HIV, but has been hard at work developing a broad pipeline of therapies for Hep C," JPMorgan analyst Geoff Meacham said in a research note.

Gilead projected the deal would hurt its earnings through 2014 but boost them after that. It said it expects to close the acquisition in the 2012 first quarter, and will provide a further outlook at that time.

Gilead will temporarily suspend its share repurchase program in order to focus on paying down debt.

It said it would finance the deal with cash on hand, bank debt and senior unsecured notes. It said it had financing commitments from Bank of America Merrill Lynch and Barclays Capital.

Barclays and Bank of America advised Gilead on the deal, while Morgan Stanley advised Pharmasset. Skadden, Arps, Slate, Meagher & Flom LLP is Gilead 's legal counsel, while Sullivan & Cromwell LLP is serving as legal counsel to Pharmasset.

(Reporting by Lewis Krauskopf in New York ; additional reporting by Anand Basu in Bangalore and Toni Clarke in Boston ; Editing by Michele Gershberg, Esha Dey and John Wallace)

Rare strain of AIDS virus moves beyond Cameroon

(AFP) – 24 November, 2011

PARIS — A very rare strain of AIDS virus previously found only among a few people in Cameroon has most probably spread outside the West African country, according to a case reported by The Lancet on Friday.

The first identified infection with the so-called "group N" strain of the human immunodeficiency virus (HIV) was found in 1998 in a Cameroonian woman who had progressed to AIDS.

Since then, more than 12,000 HIV-infected patients living in Cameroon have been tested for group-N infection, but only 12 cases, including two couples, have ever been found.

The new case, reported by French doctors, involves a 57-year-old man who was admitted to the Saint Louis Hospital Paris in January suffering from fever, rash, swollen lymph glands and genital ulceration.

The patient had high levels of a virus in the HIV-1 family, but tests to pinpoint the particular strain proved inconclusive. On February 9, the patient developed facial paralysis.

The French team then carried out further tests on blood samples, which were found to react in an antibody essay of the N strain.

Tracing his sexual history, the researchers believe the infection was "probably" acquired from intercourse with a partner in Togo , from which he had just returned.

"This case of HIV-1 group-N primary infection indicates that this rare group is now circulating outside Cameroon , which emphasises the need for rigorous HIV epidemiological monitoring," says the doctors, led by Professor Francois Simon.

The finding is important because the patient suffered not only severe symptoms but also a fast-track decline in his immune system, as shown in the number of his CD4 white blood cells.

He was given a powerful five-drug combination of antiretrovirals, to which he responded, but needs close monitoring in the future, the letter said.

Group N may have leapt to humans from chimpanzees, possibly through the handling of bushmeat infected with the simian equivalent of HIV, scientists say.

It is one of four sub-types of virus gathered in the HIV-1 family, the others being M, which is by far the most prevalent, O and P. The P strain, like O and N very rare, may have jumped to humans from gorillas, according to a study published in 2009.

There is also a minority viral family called HIV-2, which also may have passed to humans from animal primates.

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