sábado, 24 de setembro de 2011


entagon rethinks bioterror effort

Critics say US$1.5-billion initiative has not delivered results.
Soldiers are yet to see any effective new countermeasures against bioterror agents.Soldiers are yet to see any effective new countermeasures against bioterror agents.K. KULISH/CORBIS
In the film Contagion, it takes just a few months for scientists to make a vaccine against a deadly virus. Yet a real US military programme that aimed to do just that is being dismantled after five years of trying.
The Transformational Medical Technologies (TMT) initiative, born in the US Department of Defense in 2006, was originally conceived as a five-year, US$1.5-billion project that would substantially accelerate the development of countermeasures to protect soldiers against biological attacks. Made into a permanent programme in 2009, it set out to sequence the genomes of potential bioterror agents, explore new drug technologies and develop 'broad-spectrum' therapies that would work against multiple bacterial and viral pathogens — especially haemorrhagic fever viruses such as Ebola and Marburg. Supporters of the programme point out that three candidate drugs developed under the programme, for pathogens including Ebola virus, are now in clinical trials.
The TMT programme, however, has ceased to exist as a stand-alone effort. Alan Rudolph, director of Chemical and Biological Technologies for the TMT's parent office, the Defense Threat Reduction Agency, is folding some TMT projects into other Pentagon efforts and reordering their priorities. Critics say that it has failed in its underlying objective to provide a faster, game-changing approach to biodefence. No antibiotics developed by the TMT have entered clinical trials. The drug candidates it has developed are designed for single pathogens, not multiple threats. And although the programme is set to award a major clinical-trial contract later this year, the drug being tested would treat not exotic, untreatable pathogens but ordinary influenza, a disease already heavily researched outside the Pentagon.
Michael Osterholm of the University of Minnesota's Center for Infectious Disease Research and Policy thinks that the programme was overambitious and ill-conceived. "They're wasting tonnes of money," he says.
The programme's architects have vigorously defended its record. "There is a success there that we need to build on," says Jean Reed, who, as deputy assistant to the secretary of defence for chemical and biological defence and chemical demilitarization, laid the plans for the TMT. Now a consultant to the National Defense University in Washington DC, Reed adds that the programme has become the archetype within the defence department for the "development of treatments for biologically engineered and naturally occurring disease threats".
"The TMT from its inception was a high-risk, high-payoff or high-failure effort," says David Hough, who became TMT programme manager in January 2007. He says that the effort has paid off: "If we get an engineered threat or something that we haven't seen before that is causing a lot of deaths, we think we can respond to that." He says that the programme's track record is better than that of the Pentagon's traditional chemical and biological defence research effort over the past decade.
Although the TMT aimed to transform biodefence, it encountered many of the roadblocks that have hindered the nation's biodefence effort as a whole, which has spent $60 billion since 2001 with only modest returns (see Nature 477, 150–152; 2011). Developing broad-spectrum drugs for the battlefield has proved difficult because regulators are more accustomed to evaluating drugs that target one specific disease, and drug companies prefer to focus on diseases that affect many people rather than on obscure pathogens that could serve as bioweapons.
These considerations helped to lead the TMT into focusing on influenza in 2009. That year, US government officials were faced with the double threat of H1N1 swine flu, which threatened to explode into a devastating pandemic, and the more deadly H5N1 bird flu virus, which was continuing to infect small numbers of people.
Government officials were "practically paralysed by the fear that they were dealing with two strains at a time; they didn't know what they were going to do", says Darrell Galloway, Rudolph's predecessor at the Defense Threat Reduction Agency, who was a driving force for the TMT from its inception until he retired in January 2010. Galloway saw influenza as an opening to prove the programme's worth. In May 2009, he awarded a contract to AVI BioPharma of Bothell, Washington, to make a flu drug against the H1N1 virus, using its genetic sequence as a basis. Within months, the company had made a drug and tested it in ferrets.
Yet the move angered some within the Pentagon and perplexed observers, because influenza is the focus of considerable research funded by the US Department of Health and Human Services. "I'm having a really hard time making a connection between the investments we're making and the benefit to soldiers," said one staff member at the Defense Threat Reduction Agency.
The TMT also stumbled because companies attracted to biodefence tend to be small and inexperienced. Larger, established companies prefer to pursue more profitable markets, fearing that the federal government will commit to stockpiling only limited amounts of drugs developed for defence purposes.
The company behind all three TMT drugs now in clinical trials, AVI BioPharma, has never had a drug approved by the US Food and Drug Administration. The company's technology uses antisense, in which short pieces of genetic material bind to a pathogen's genes and block their production. The technology has led to few approved drugs owing to safety problems and a lack of efficacy. Still, the TMT and the Army awarded the company a $291-million, six-year contract last year to fund two clinical trials, for its drugs against Ebola and Marburg viruses. Now AVI BioPharma has set its sights on a contract for clinical trials of its antisense drug for H1N1.
AVI BioPharma's chief executive, Chris Garabedian, says that the company's technology is safer than that tested by other drug firms, and thus can be used in higher doses that are more likely to be effective than other antisense drugs that have failed in the past.
But critics say that it was a mistake for the TMT to invest so much in a technology that does not have a proven track record in infectious disease. "Everybody in that field thinks antisense is a failure, except the [defence department] programme manager," says one biodefence analyst, who did not want to be named.
SOURCE: US DEPARTMENT OF DEFENSE
Rudolph, who succeeded Galloway last September, controls the chemical and biological defence research budget, which includes standard drug- and vaccine-research programmes as well as the TMT. Rudolph is combining the TMT research money (see 'The cost of countermeasures') with that for traditional projects, and refocusing on four priorities: surveillance and diagnostics, sensors, countermeasures and decontamination technologies.
Rudolph has retained some TMT projects, such as the pathogen-sequencing studies led by Ian Lipkin of Columbia University in New York, who was a technical adviser on Contagion. But he has cut others, such as a five-year, $24.7-million contract awarded in 2008 to Peregrine Pharmaceuticals of Tustin, California, to find antibodies against haemorrhagic fevers. The TMT funding for AVI BioPharma's two clinical trials will continue, however, as the trials are managed separately by Hough.
Whether the dismantling of the TMT will improve the Pentagon's biodefence success rate remains to be seen, says Tom Inglesby at the Center for Biosecurity of the University of Pittsburgh Medical Center in Baltimore, Maryland. "In the end, the question will be, 'Did Rudolph make progress in the time he was there with the money that he had?' Ultimately, he will be held accountable." 

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  • #26903
    WHAT A CHEAP SHOT,LISTEN AVI BIOPHARMA IS NOT AT ALL LIKE OTHER ANTISENSE COMPANIES FOR ONE .AVI BIOPHARMA CHANGED FROM A RESEARCH COMPANY IN 2007 TO A RESEARCH AND DRUG MAKER THEN.WHAT DO YOU EXPECT FROM A COMPANY THAT HAS JUST GOT IN TO FDA TRIALS A SHORT WHILE AGO FOR EBOLA/MARBURG.I AM WILLING TO BET YOUR FUTURE THAT AVI'S DRUGS WILL AVAIL BETTER FOR ANTIVIRALS THAN ANY OTHER TREATMENT ONCE THEY CAN GET THROUGH THESE NEVER ENDING FDA TRIALS.I THINK THE WRITTER HERE NEEDS TO RESEARCH CURRENT AFFAIRS ON WHOM IS TELLING MISS LEADING INFO TO THEM AND RESEARCH THE REAL CURRENT SCIENCE BEFORE SUCH A STORY.
  • #26904
    The anonymous source who claims "everybody knows antisense is a failure" should be telling that to the parents of the Duchenne Muscular Dystrophy boys now being dosed in the AVI trial for DMD that is the current best hope for these people. And it's generally expected to work, not fail. The same success is being encountered in the bioterrorism applications. If the writer had chosen to do a bit more looking into the programs than he's done for the reader here, he'd have known that too. But then he'd have had to write a very different article. Perhaps he should.
  • #26908
    I've worked in the oligonucleotide field for more than 20 years, and it's true there are only 2 approved drugs. So? The development of any new platform requires a lot of time, and the same was true of the monoclonal Ab field at the equivalent stage of development after the discovery of how to make monoclonal Ab in 1975 (the comparable starting date for antisense technology is the late 1980's, with the development of automated DNA synthesis). It's true that early antisense chemistries (phosphorothioate) had relatively poor antisense efficacy in humans, but I think it's inaccurate to say safety issues are holding the field back. Moreover, newer chemistries (like the morpholino used by AVI) show far more promise, and are effective (and well tolerated) in ongoing human clinical trials. The robust stage of this field is reflected in the fact that there are more than 10 compounds in phase 3 clincial development, and dozens in phase 2. I have my own biases, but the characterization of the antisense field as a "failure" is quite premature, and does not reflect an understanding of it's current state.
  • #26927
    Morpholino antisense oligos have shown their efficacy for gene knockdowns in biological research, where they are routinely used for knockdowns in embryos, primarily zebrafish and Xenopus. Other knockdown types, such as siRNA or phosphorothioate RNA (which gave the antisense field its bad reputation in the '80s-'90s), kill zebrafish embryos. Delivery of oligos into cells from the blood is still a problem in many cases, though the higher doses allowed by the non-toxicity of the Morpholino backbone can help drive delivery and the leakiness of cells with Duchenne muscular dystrophy has advantaged Morpholinos for treatment of that disease. I work for the company that manufactures Morpholinos for researchers, and from my perspective the Morpholino work at AVI BioPharma has great promise for DMD and, based on the published reports for their modified Morpholinos (PMO+) in viral knockdowns, they have a reasonable chance of clinical success.
  • #26929
    I have taught biochemistry for over 35 years and PMO's have been a tool I have used in the lab for the last 10 years. 1 year ago I reviewed the 2 ferret studies conducted by the DOD/Avi Biopharma utilizing the PMO+ chemistry and was taken aback by the antiviral effect of this chemistry. In the preferred animal model for influenza A [ferret] the PMO+ chemistry reduced the viral load in these mammals by a 5.9 LOG10. The positive control in these 2 studies was Tamiflu. Tamiflu treated ferrets had a reduction of viral load by the order of .54 LOG10. The PMO+ chemistry targets the conserved region of the influenza A virus resulting in the inability of the virus to successfully mutate around this antiviral. This antiviral will save lives. This brings me to why I felt compelled to respond to "The Nature's News" report that "unnamed" sources were appalled at the money thrown at this antiviral. Succinctly put, I can see why large pharma would want to sabotage the lifeline[money]for promising, small biotech incubators like Avi Biopharma but I don't understand why you would add credibility to these "unnamed sources" by publishing these slanderous comments. Data does not lie.
  • #26941
    Whoever made the above statement should study the pandemic of 1918, in which the USA military not only suffered an enormous number of deaths but were also credited in carrying the virus throughout the world due to WW1 troop movements.
    Virologists around the world agree that it is not a question of if highly virulent pandemics will again occur, but rather when!
    It will be far too late to develop quality treatments when the next pandemic happens. They must be developed now, regardless of the mutation.
    Fortunately, TMT has had the insight to understand and take action.
  • #26943
    When fighting unforseen pathogens, the idea is to find a rapidly adaptable technology that works broadly. That is the justification for targeting flu. If a medical countermeasure proves safe and effective against flu, we can be confident in its ability to be adapted to fight other viruses in the event of possible biological attacks or natural outbreaks. The author makes no mention of the successful rapid-response exercises that have been conducted. The development of this ability, which is crucial in our country's readiness, and the outcome of the current human safety trials should be the measure of TMT's success. Furthermore, just getting drugs to human safety trials should be applauded because this is not easy when dealing with relatively new technologies. The opinions of an unnamed analyst who's motives are unknown, to me is not worth much. Also, an agency created only 5 years ago that has not produced a new FDA-approved drug should not be considered a failure because the timeline for getting new drugs to market is much longer than 5 years. Erika Check Hayden should at least offer alternative strategies that could be employed to ready the nation for biological threats. Or at least the unnamed sources should be able to offer up some ideas.
    The author also seems to be confused with two concepts: One where an emergency (Such as in Contagion) causes the government to bypass normal standards and rush a drug to production in order to stave off disaster. The other, is what we currently have: An agency helping along a technology through the long, expensive process of development before an emergency hits. So, contrary to the lede of the story, TMT has not spent 5 years and failed to produce a treatment for a deadly virus. In fact, it took much less time than "a few months" like in Contagion. The drugs for Ebola, Marburg and now influenza all were created by Avi-biopharma in a matter of days and are now being tested for safety. Avi-biopharma has also created several other drugs using the same technology during rapid-response exercises, all of which could conceivably be used in an emergency, but will need funding in order to go to clinical trials.