News (Updated October 14, 2007)
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By Ben HirschlerThu Oct 11, 2:49 PM ET
AIDS researchers must step up collaboration following the failure last month of a key experimental HIV vaccine, the new head of a global group coordinating the hunt for an effective shot said on Thursday.
Merck & Co, which had been working with the U.S. government-funded HIV Vaccine Trials Network, halted testing of its vaccine because it did not prevent subjects becoming infected in a clinical trial.
It was long considered one of the most promising vaccines in development and the failure was a major blow to the global effort to stem infections with the virus that causes AIDS.
Alan Bernstein, the founding president of the Canadian Institutes of Health Research, who has now been appointed first executive director of the Global HIV Vaccine Enterprise, said the setback underlined the need for cooperation to speed up vaccine work.
Bernstein's job as head of the group -- which has a new secretariat in New York -- is to bring together academics, drugmakers, governments and regulators to work on a common strategy.
"This trial was yet another eye-opener for the need for the Enterprise," he said in a telephone interview from Cape Town.
"We need a mechanism for everybody from scientists to volunteers to get around the table and talk and agree on a common way forward," he said.
"The AIDS challenge is too important for anybody to say they have a right -- whether it's public or private money -- to keep things secret."
Around 40 million people worldwide are living with HIV and nearly 5 million are newly infected every year. But making a vaccine against HIV has proved extremely difficult because the virus mutates rapidly and it infects the very immune system cells that are usually stimulated by a vaccine.
Bernstein said the failure of the Merck vaccine was a blow but he cautioned against reading too much into the setback.
"It's a mistake to put all our eggs in one basket and think one trial is make-or-break for the field. I don't think that's the case in science," he said.
Merck's vaccine aimed to stimulate the body's killer T-cells to attack HIV-infected cells. The more conventional strategy, stimulating antibodies, has proved very difficult with HIV.
In future, a twin-track approach may be needed to exploit both arms of the immune system, Bernstein believes.
The Global HIV Vaccine Enterprise, which was set up with money from the Bill & Melinda Gates Foundation, has to date mobilized $750 million in support of its scientific plan.
Fri Oct 12, 2007 6:24 PM ET
By Kim Dixon
WASHINGTON (Reuters) - A new AIDS treatment made by Merck & Co, the first in a new class of drugs aimed at preventing replication of the virus, has been approved by U.S. regulators, Merck said on Friday.
The drug will be available in about two weeks, Merck said.
The U.S. Food and Drug Administration cleared Isentress, a pill given twice a day and known generically as raltegravir. An FDA advisory panel recommended approval of the drug in September.
It is the first in a new class of HIV treatments called integrase inhibitors that seek to block insertion of HIV genetic material into human DNA to prevent the creation of copies of the virus.
"It seems very safe, compared to other agents. It is very potent in terms of HIV viral suppression," said Dr. Homayoon Khanlou, the AIDS Healthcare Foundation's Chief of Medicine, who was involved in the clinical testing.
Cowen & Co analysts have forecast that the drug could reap up to a $1 billion in sales by 2012. The drug could compete with a similar therapy being tested by Gilead Sciences.
Isentress was approved based on testing for 24 weeks in combination with a current therapy in about 700 patients who have become highly resistant to several marketed medicines for HIV, the virus that causes AIDS. The disease is often treated with a mixture of several medicines.
The company promised to study the drug for at least five years to monitor any side effects that might not have shown up in its initial clinical trials.
Resistance is a major problem as the human immunodeficiency virus (HIV) that causes AIDS can mutate, especially in patients who fail to rigorously follow the often complicated drug regimes.
The drug-resistant patient population has the highest unmet medical need, according to Merck, which is also studying the drug in previously untreated patients.
Merck estimates about 500,000 patients in the United States are getting the standard anti-retroviral therapy, and that between 30 and 40 percent of them have failed several regimes, suggesting they are developing resistance.
The company said it would charge about $27 per day, or $9,855 annually, for the drug. Steep prices for AIDS drugs have been criticized by patients and advocacy groups, who say they deter use of life-saving drugs.
"If the agent cost $10,000 (a year), for example, you are not going to be able to use it in everybody. The cost is always an issue," Khanlou said.
Because of treatment advances, more people are living longer with HIV or AIDS. In the United States alone in 2006, more than 1 million people were living with HIV or AIDS. An estimated 40,000 new cases are expected this year, according to the U.S. Centers for Disease Control and Prevention.
Serious drug-related adverse events reported in the Merck studies included anemia, heart attack and low white-blood cell count, Merck said.
There was also a larger number of malignant cancers in the group studied with Isentress, a topic discussed at length at the FDA's advisory panel. The cancers were types common among AIDS patients.
Merck has said the difference between the occurrence of these cancers in the Isentress group and the control group narrowed over time, though they were still more common in the Isentress group.
(Reporting by Kim Dixon)
Tue Oct 9, 2007 8:27 PM BST
WASHINGTON (Reuters) - Cocktails of drugs widely used to treat infection with
the AIDS virus appear to stop brain damage caused by HIV as well, researchers
reported on Monday.
Writing in the journal Neurology, the researchers said their study also pointed to a way to measure this progressive brain damage when it does occur.
The AIDS drugs combinations, known as highly active antiretroviral therapy or HAART, suppress the virus but do not remove it completely from the body. Patients are not cured but their immune systems are not as badly damaged as untreated patients.
HIV can also attack the brain and nerves. Before HAART was available, about 20 percent of people with AIDS developed dementia. But not all of the drugs used in these mixtures get into the brain, so it was not clear how much they helped.
Dr. Asa Mellgren of Goteborg University in Sweden and colleagues studied 53 men and women infected with HIV. They tested their cerebrospinal fluid, then gave them HAART for one year.
Before treatment, 21 of the patients had high levels of a protein called neurofilament light protein, which was believed to point to brain damage.
After three months of taking HAART, those high levels of protein fell to normal levels in nearly half of the patients. After one year of treatment, only four people still had high levels of the protein, they reported.
All but one of the patients with normal levels remained normal for the year.
"This type of treatment appears to halt the neurodegenerative process caused by HIV," Mellgren said in a statement.
"This study confirms that neurofilament light protein serves as a useful marker in monitoring brain injury in people with HIV and in evaluating the effectiveness of HAART."
Fri Oct 12, 2007 9:37 AM ET
By Will Dunham
WASHINGTON (Reuters) - There are major differences among U.S. Hispanics in how they get infected with the AIDS virus depending on where they were born, officials said on Thursday, requiring more care in tailoring prevention efforts.
The trend was detailed in a report by the U.S. Centers for Disease Control and Prevention on HIV infection and AIDS among Hispanics, who make up 14 percent of America's population.
"In terms of the prevention messages, if you are looking at Hispanics, you can't look upon them as a monolithic group. You have to think about the various subcategories," Dr. Ken Dominguez, a CDC epidemiologist and one of the authors of the report, said in a telephone interview.
Infection through male-to-male sexual contact was more common among Hispanics born in South America (65 percent of HIV infection cases), Cuba (62 percent) and Mexico (54 percent) than among Hispanics born in the United States (46 percent), the CDC report said.
A greater proportion of Hispanics born in the Dominican Republic (47 percent) or Central America (45 percent) were infected through high-risk heterosexual sex compared with Hispanics born in the United States (28 percent).
Hispanics born in Puerto Rico had a greater proportion of human immunodeficiency virus infections due to injection drug use (33 percent) than those born in U.S. states (22 percent).
Immigrants born in Cuba, Mexico and Puerto Rico who were injection drug users reported less AIDS knowledge than U.S.-born injection drug users, the report said.
CULTURAL, SOCIOECONOMIC DIFFERENCES
The CDC said its findings were based on data provided by 33 of the 50 U.S. states in 2005.
"We're a very diverse community," Dennis deLeon, president of the New York-based Latino Commission on AIDS advocacy group, said in a telephone interview.
"We're diverse in how long we've been here (in the United States). We're diverse in our levels of education. We're diverse in our health literacy. And I think for too long the CDC has been treating Latinos as all the same," deLeon said.
The report attributed the findings in part to cultural and socioeconomic differences among Hispanic subgroups, including the stigma associated with homosexuality.
According to the CDC report, from 2001 to 2004, HIV infection diagnosis rates declined by 4.7 percent among Hispanics males and 13 percent among Hispanic females.
DeLeon questioned the finding about dropping infection rates because he said the report did not include data from some key states including heavily Hispanic California.
Overall, the mode of HIV infection for 61 percent of Hispanic males was male-to-male sexual contact, while 17 percent of infections occurred through heterosexual contact and 17 percent through injection drug use, the CDC said.
Among HIV-infected Hispanic women, 76 were exposed through heterosexual contact and 23 percent through injection drug use, the CDC said.
The report noted that Hispanics face disproportionate rates of HIV infections, with the second-highest infection rate among all U.S. racial and ethnic groups, behind blacks.
"The rate of HIV diagnosis for Hispanic males is about three times higher than the rate among white males. And for Hispanic females, it's about five times higher than among white females," Dominguez said.