AIDS Treatment News
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Protease Inhibitors
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The big media story from the 3rd Conference on Retroviruses and Opportunistic Infections concerned two protease inhibitors, one developed by Abbott Laboratories, the other by Merck & Co. Triple combination trials, which combined each of these experimental drugs with two approved AIDS drugs, showed exceptionally promising results.
The overall outcome was not a surprise, as the general picture has been discussed quietly among inside-track researchers, physicians, and activists for several weeks. But the data had not been available before. The ritonavir article below will look at the details of the new Abbott trial results, and at other research on this drug presented at the conference. Next week we will look at the Merck protease inhibitor, and at other news from the conference, which was an important meeting even aside from the high-profile protease inhibitor reports. For More InformationAlso, audio tapes of many of the sessions of the 3rd Conference on Retroviruses and Opportunistic Infections are available from Sound Images, Inc. 7388 South Revere Parkway, Suite 806, Englewood, Colorado, 303/649-1811, fax 303/790- 4230. Probably the most important single set of tapes is for Late Breaker Session #1, which includes the major Abbott and Merck reports.
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Protease Inhibitors in Human Testing:
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This brief directory of some protease inhibitors includes company, generic name, brand name if known (in parentheses), and comments. It is included to help readers follow our coverage of these drugs.
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Ritonavir (Abbott Protease Inhibitor)
by John S. James
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The most important single presentation at the Retroviruses conference was the report from Abbott Laboratories that its protease inhibitor, ritonavir, reduced the risk of death by 43% in a clinical trial with 1090 volunteers. This is the first time that a protease inhibitor has been proven to extend life. Abbott ran this study remarkably quickly; the volunteers were recruited between April and July 1995, and yet the researchers were able to report survival results in late January.
All the volunteers had a CD4 (T-helper) count of 100 or less; the median CD4 count was about 30, and about a quarter of the volunteers had counts under 10. All had used approved antiretrovirals (mostly AZT and d4T) for more than nine months. These volunteers were randomly assigned to receive either ritonavir (600 mg twice daily) or placebo for one year. But after four months, anyone who developed an AIDS- defining event was allowed to end the placebo phase of the study and use the drug. In addition to the study drug, the volunteers were permitted but not required to continue using up to two other anti-HIV drugs; if they chose to do so, they needed to be on these drugs for at least six weeks before entering the study. 3TC was not permitted, since it was not officially approved when this trial started, although it was widely available in an expanded-access program. Also, volunteers were not allowed to use any other protease inhibitor. The double-blind portion of this one-year study was stopped early because it reached a predetermined stopping number of 191 clinical outcomes. The 43% reduction in risk of death was found after the volunteers had been in the study for a median of 6.1 months. (The improvement was even more impressive after the first month of the study, with a reduction in the risk of either an AIDS-defining event or death of 58%. The risk reduction was somewhat less for CMV retinitis than for other AIDS-defining conditions.) Both the six-month survival result, and the one-month progression-or-survival result, were statistically significant. On the other hand, 17% of the volunteers on ritonavir had to discontinue treatment due to adverse events, as compared to a 6% discontinuation rate on the placebo. Viral load, CD4, and CD8 measures were studied in a subset of the volunteers in this trial, and were reported in a separate paper, reviewed below. Ritonavir is the only protease inhibitor so far to have proven survival benefit. It is widely suspected that other protease inhibitors would have comparable results if they were tested the same way. But in view of Abbott's result, as well as new information about viral load, there would be ethical problems in running the same placebo trial with other drugs. CommentIn all past trials it has been very difficult to prove a survival benefit from a drug. (The earliest controlled study of AZT did show a survival benefit of AZT vs. placebo, but that result is not entirely credible because of problems with the trial.) How could Abbott prove survival benefit today in such a short time? There are basically two reasons. First, the new protease inhibitors, especially in combination with other antiretrovirals, are much more effective against HIV than previous treatments were, making it easier to show a difference between treated and untreated patients. Also, Abbott overcame the widespread industry prejudice against allowing volunteers with very low CD4 counts in trials. Many researchers had come to believe that these patients were too advanced to benefit from antiviral drugs; companies excluded them so that their drugs would look good. But the belief that these people could not benefit came from experience with much less effective drugs. In addition, for several years it has been known that when persons with AIDS are receiving excellent medical care, almost all the deaths occur in those with a CD4 count below 50. Abbott realized that the very people who were being excluded by other companies were the ones it needed to prove that its drug could prolong life. Recruiting patients is often the critical weakness of clinical trials. The ritonavir trial recruited quickly because persons with a low CD4 count had no other trials available, because Abbott opened 67 trial sites in the U.S., Europe, and Australia, and because persons in the trial could continue the anti-HIV medications they were already using. This trial has been well accepted by patients and activists. Ritonavir does have a major disadvantage, however. It interacts with many other drugs by preventing them from being metabolized by the body, causing the normal dose of some drugs to become a dangerous overdose. Some medications can be used with appropriate dose adjustments; others cannot be combined with ritonavir at all. The Merck protease inhibitor indinavir (Crixivan(R)) has much less of a drug-interaction problem, and probably at least as much ability to suppress HIV as ritonavir does. But it does not have data proving that it prolongs survival. Where do we go from here in proving clinical benefit? Must every new protease inhibitor prove that it can extend life? We think not, for several reasons:
We believe that clinical-endpoint trials should be used very selectively, and no longer be required by the FDA for every new drug. Resources should be shifted to rapid trials which look at viral load, CD4 counts, and other measures of HIV disease status, to determine how well treatments are working -- trials which include long-term followup. Resources now spent on confirming final certainty in regulatory decisions should be focused instead on answering physicians' practical questions on how best to use the drugs. What about the risk of long-term drug toxicity? This is always a danger; but is the best way to look for it a randomized trial designed to determine whether or not the drug works against the disease? If the benefit and harm of the drug are nearly balanced, then a clinical-endpoint trial might be necessary to tell which was greater. But today there are many protease inhibitors and combinations with major impact on HIV; a drug which caused equivalent damage in side effects would be abandoned long before such a trial could be completed. This issue remains controversial, however, because in theory at least, clinical benefit trials still offer the most certain proof that a drug does more good than harm. Many people are philosophically attached to this promise of certainty. [Note: The ritonavir survival results were presented in the "late breaker" session of the conference, abstract #LB6a. The late breaker session is for results which are too recent to have been submitted by the regular deadline, but important enough to be accepted anyway.] Other Ritonavir ResultsThe following additional results on ritonavir were presented at the Retroviruses conference:
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Agouron Starts Phase III
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Agouron Pharmaceuticals, Inc. is starting two large studies of its protease inhibitor VIRACEPT(TM) (nelfinavir mesylate) in combination with approved HIV drugs. A smaller study of nelfinavir alone is also beginning.
One trial, protocol 506, will study two doses of nelfinavir (500 and 750 mg) combined with stavudine (d4T), vs. stavudine alone. Volunteers will have a two-thirds chance of getting one of the combination regimens. This trial will enroll 240 patients; three quarters of the slots are for persons who have been treated with AZT for at least six months, and the other 25% are for those who have either had no AZT use, or less than six months of it. Volunteers must be at least 13 years old, and must have a CD4 count of at least 50 and a viral load of at least 15,000 copies. They cannot have used any protease inhibitor, nor d4T, at any time. In case of treatment failure (defined as return to baseline viral load, CD4, or both on two consecutive visits following four weeks of drug administration), certain treatment changes will be allowed. This study will last 24 weeks, and may provide drug for an additional six months. Another trial, protocol 511, will study the same two doses of nelfinavir in combination with AZT plus 3TC, vs. AZT plus 3TC alone. Volunteers will have a two-thirds chance of getting a triple combination treatment. They must be at least 13 years old, and have a viral load of at least 15,000 copies. They can have any CD4 count, but cannot have received any anti-HIV drugs except for a lifetime total of less than one month of AZT. This study will last for 24 weeks, after which drug may be provided for another six months. Provisions similar to protocol 506 are available for treatment failure. This study is seeking to enroll 210 patients. Protocol 505 will study the same two doses of nelfinavir alone, compared to placebo. After four weeks, the placebo volunteers will be randomized into one of the treatment groups. Volunteers must have a CD4 count of at least 50, and a viral load of at least 15,000. For more information about these trials, which are now recruiting in about 30 cities in the U.S., call Agouron's information line, 800/501-2474, and follow the voicemail instructions to find a contact number in your city. CommentIt is difficult for patients and physicians to make decisions about protease inhibitor therapies at this time. The main disadvantage of the Agouron drug is that much less is known about it than is known about the Merck, Abbott, or Roche protease inhibitors. On the other hand, it may not have some of the drawbacks of those other drugs. For today and for the near future, there is no way to know which treatment options are best.
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Vancouver International Conference:
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The February 1 deadline to apply for an NGO (non-government organization, i.e. not-for-profit organization) booth at the XI International Conference on AIDS (Vancouver, July 7-12, 1996) has been extended. There is no charge for these booths, but a deposit is required, to discourage organizations from reserving space and not using it.
For more information, call the XI International Conference on AIDS, Exhibit Management Office, attn: Ms. Val Levy, 1030 Mainland St., Vancouver, V6B 2T4, 604/688-0855, fax 604/688- 0270.
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FDA Antiviral Advisory Committee Meetings |
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The Antiviral Drugs Advisory Committee has four AIDS-related meetings in the next month; all are open to the public, and public testimony will be taken. Note that some information about the locations which was published in the FEDERAL REGISTER on January 31 is erroneous.
February 28, 8:30-5:00: Recent studies with nucleoside analogs (ACTG 175, the Delta study, and others), and how the results should affect standard of care. February 29, 8:30-5:00: Ritonavir (Abbott Laboratories protease inhibitor). March 1, 8:30-5:00: Crixivan(R) (Merck & Co. protease inhibitor). March 1 also, 8:00-5:00: A joint meeting of the Antiviral Drugs Advisory Committee and the Endocrine and Metabolic Drugs Advisory Committee, on Serostim(TM) (human growth hormone) to treat AIDS-related wasting. (This meeting will be at the Holiday Inn, Silver Spring, Maryland; the other three meetings will be at the Holiday Inn, Gaithersburg, Maryland. The Antiviral Drugs Advisory Committee will be divided for the two simultaneous March 1 meetings.) For the most current information, call the FDA Advisory Committee Hotline, 800/741-8138. When it asks for a 5-digit code, enter the code for the Antiviral Drugs Advisory Committee, 12531.
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Prisoners: Send Address Updates;
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If you are transferred or released, send us your new address if you want to continue receiving AIDS Treatment News. We will automatically continue a free subscription for six months after you are released; after that time you can use our regular sliding scale if you have financial difficulties. But if you do not send us a forwarding address, our mailings are returned and there is no way we can contact you.
Also, in our January 5 issue (#238) listing of AIDS organizations, we only had space to publish telephone numbers, not addresses. If you need to contact one of those organizations but cannot call them, you can send a letter to us, and we will forward it to them for you.
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NMAC Skills Building Conference
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The National Minority AIDS Council, working with several other organizations, will hold the NMAC Skills Building Conference for South African Community-Based AIDS Service Providers, in Johannesburg, April 15-19. NMAC is now seeking ten facilitators to help with this training conference; two will receive full travel expenses, the others partial expenses.
Applications are due February 20. For more information, call Jackyie Coleman or Harold Phillips at 202/483-6622.
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Computer Censorship Law,
by John S. James
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On February 1 both houses of Congress passed The Communications Act of 1995, the major telecommunications bill which includes the computer censorship provisions described in previous issues of AIDS Treatment News (issues #227, #229, #236, #237, and #238). The censorship legislation will take effect when Clinton signs the bill, probably on February 8.
Unless the Supreme Court rules the provision unconstitutional, it is now a felony punishable by five years in prison for anyone in the U.S. to just RECEIVE an "obscene" communication by computer, even in your own home by private email or otherwise, even if you never show it to anyone -- up to ten years for the second and each subsequent reception, with a fine for each offense up to $250,000. You do not need to know that the communication is legally obscene -- just knowing it is sexually oriented is enough. By the time you see it to judge whether it is obscene, the crime has already been committed. And if you used the Internet, open-and-shut evidence against you passed through any number of different sites controlled by different organizations, and can remain there for years, legally dangerous until the statute of limitations expires. Abortion became an issue on the day of the final vote in Congress, because the same legislation likewise makes it a felony to knowingly receive by computer (as well as to send) any information about how an abortion pill or other device can be obtained or made. Members of Congress disagree as to whether all of the prohibition of abortion information has already been ruled unconstitutional. As a compromise, some sponsors of the censorship legislation read language into the CONGRESSIONAL RECORD saying that Congress did not intend the telecommunications bill to criminalize abortion information; this might help if someone is prosecuted for discussing abortion by computer. Congress was unwilling to make any change in the language of the bill, however, because it was determined to pass the entire telecommunications bill that day or the next, before it went home for recess. (For more information on this abortion controversy in the telecommunications bill, see the SAN JOSE MERCURY NEWS, February 2, page 1.) These obscenity and abortion provisions of the law have nothing to do with the protection of minors, since they apply to anyone, even if no minor is involved in any way. About the only fact in your favor is that prosecution would presumably have to occur in your local area, or wherever you were when you received the message (not anywhere in the country, as with other sections of the law); in many areas, such as San Francisco, malicious or political prosecution of an inadvertent or incidental offense would seem unlikely. And the law applies to "interstate commerce," so it might not apply to local use of a local bulletin board not connected to the Internet. Few members of Congress even knew that this provision was in the legislation until the day of the vote on the entire telecommunications bill, when the abortion issue was raised by Congresswoman Pat Schroeder. There have never been Congressional hearings on any of the computer censorship legislation; most members of Congress did not follow this issue at all. And the new crime of receiving information by computer was created by a few words in a six-page list of "technical" changes, words which apply an unrelated law (against importing pornography and abortion devices) to people who just explore on their own computer. This provision did not appear in the official text of the telecommunications bill until the morning of February 1, the day of the final vote in both houses of Congress. It never appeared anywhere in Thomas, the Library of Congress Web site intended to provide the public with the text of legislation Congress is currently considering, until after final passage. (The language has existed unofficially since December or early January, and it has been posted on public Web sites by civil liberties organizations; but it was not made official, and therefore not released to the public through usual channels, until shortly before the final vote in Congress. Those who looked where one would normally look for pending legislation did not find it. There appears to have been a deliberate effort to prevent the public from knowing, by keeping the censorship language in unofficial, unpublished status, until the day Congress cast its final votes.) The better-known provisions of the bill are equally threatening. Putting any "indecent" message on the Internet is now a felony punishable by two years in prison and a $250,000 fine -- even if the same text or picture would be legal if published in a newspaper. "Indecent" is not clearly defined -- but redeeming social importance is not a legal defense (Congress rejected a proposal to exempt such material). And the indecency legal standard is so broad that it may even include the Bible; the King James version uses one of the Federal Communication Commission's "seven dirty words," a word specifically defined as indecent by the U.S. Supreme Court (II Kings 18:27). Also, the crime is committed wherever someone under 18 RECEIVES the material, meaning that a person can be prosecuted anywhere in the country that prosecutors or influential organizations may be so inclined. This new law affects AIDS Treatment News, despite our completely non-sexual material:
This concern may seem exaggerated, when no one is likely to prosecute AIDS Treatment News for researching and running an AIDS directory on the Internet. But the issue is not only the actual risk of prosecution; also it is how we define ourselves and set the policies that build our relationships in society. We are not comfortable if enforcement of the laws literally as written could send us to prison for decades -- no matter how unlikely this is to actually happen.
Why not avoid some of the problems by restricting our Web page to adult-only areas, as supporters of the law have suggested? One major reason is that there are no adult-only areas on the Internet of any consequence -- and there never will be, no matter what technology and institutions are developed. The reason is that the Internet is what could be called an information commons -- and inherently there is only one of those, not one for adults only and another for everyone. Once you limit or restrict a commons, it is not a commons any more, but a proprietary system controlled by somebody, because someone must police the restriction. This owner, manager, or authority can then police content, too, imposing whatever political or other restrictions it wishes. You no longer have a First Amendment right to be heard, just as you have no First Amendment right to be published in a particular newspaper. When a commons has been enclosed, its essence has been destroyed. StrategyAIDS organizations had no input at all into the new censorship legislation. In the past, our strategy at AIDS Treatment News was to inform the AIDS community about the threat, so that it could have input into what Congress did. But there was no time, because the censorship provisions appeared dead until just weeks before they were locked in concrete, with Congress unwilling to change even a single word before final passage. Now that it is too late to prevent the legislation, other strategies are needed. At this time we see three:
Much of the new law is likely to be declared unconstitutional, as violating the First Amendment of the Bill of Rights. But court decisions could be many years away. And no matter what the courts do, we will need to fight this issue forever; we will need both institutional coalitions and personal working relationships with civil libertarians.
So far we do not know anyone who has learned how to do this well on the Internet. The AIDS community and others can apply their full energies to building expertise in appropriately targeted mass distribution, with confidence that this avenue will always be open, while the bill's legal consequences for participatory Internet sites are worked out. Certainly we will seek legal advice, but no one can know how the law will be enforced. Our guess is that for some time it will be enforced selectively -- usually against those actually involved with pornography, sometimes against individuals and organizations targeted for their political work (especially gays), and occasionally against ordinary people whose incidental transgression happens to come to someone's attention and fit their agenda. But if a bureaucracy of inquisition develops, it will need cases to justify its existence, and the proportion of political and incidental prosecutions will increase. The fines of up to $250,000 per message could also motivate prosecutions. Enforcement philosophy is likely to depend heavily on the political atmosphere of the time, and on who is President.
The only long-term protection is well-organized mass movements to make sure that the First Amendment rights U.S. citizens have defended throughout this nation's history are still meaningful, for today and for tomorrow. Congress could pass the current law only because it heard from very few people who knew or cared. That must never be allowed to happen again. But in civil liberties -- as also in AIDS -- we have never yet found an organization that offers meaningful participation to any willing, committed volunteer, regardless of what skills they have, and wherever they may live. Some right-wing organizations do seem able to do this. Religious groups may have an advantage, because they can offer prayer at first, allowing people to become comfortable with each other before the egos and divisiveness of politics are introduced. Building equally massive grassroots organizations to defend a free society, instead of taking freedom away in the pursuit of power, is today's critical bridge to moving forward. Test Case Filed This WeekAs this issue went to press on February 7, the ACLU announced that it is filing a test case (ACLU v Reno) against the computer censorship provisions of the telecommunication law, immediately after Clinton signs the legislation (probably February 8). The group of 20 plaintiffs in this case includes three AIDS organizations:
Other plaintiffs include Human Rights Watch (at risk because its reports include accounts of rape and torture in documentation of human-rights violations), Planned Parenthood Federation of America (which provides information on topics which include abortion), and the Institute for Global Communication (which operates a computer facility that serves about 400 nonprofit groups and 500 schools). Also note: A number of World Wide Web sites are reversing the contrast on their lettering to turn their pages black, for a two-day protest after Clinton signs the bill, which he is expected to do on February 8. For more information about this protest, contact the Voters Telecommunications Watch (vtw@vtw.org), or check their free-speech Web page at http://www.vtw.org/speech/. For More Information:American Civil Liberties Union, 212/944-9800x414 (or its new Web page, http://www.aclu.org -- or America Online, keyword 'ACLU') Center for Democracy and Technology, http://www.cdt.org Electronic Frontier Foundation, http://www.eff.org Voters Telecommunications Watch, http://www.vtw.org/, or vtw@vtw.org |
This article was provided by AIDS Treatment News. It is a part of the publication AIDS Treatment News.|
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