Transcript Rectal Microbicides

Rectal Microbicides:
New Hope for
HIV and STD Prevention
www.global-campaign.org
Objectives
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Why we need rectal microbicides
What is involved in development
Where the research is
What you can do to get involved
www.global-campaign.org
Men at risk
• High rates of condom use are difficult to
maintain, as the rate of new HIV
infections shows
• New data reveals reasons for concern:
–UK: 48.8% UAI in the past year
–US: 30% UAI (HIV - men in past year)
• STD rates confirm UAI prevalence
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Women at risk
• In large US survey, 35% of women age
25-44 report having had anal sex at
some time in their life
• 32% of high-risk women reported anal
sex in past 6 months (Gross et al, 2000)
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What is a microbicide?
Microbicides are substances that can reduce the
transmission of HIV and other STD pathogens when
applied vaginally and, possibly, rectally.
They are not yet available.
Currently, they are formulated
as lubes, gels or creams applied
with an applicator like those
shown here
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We need a product
that is…
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Inexpensive
Easily accessible (over the counter)
Easy to use
Safe, non-irritating
Available in various forms (in lubes,
suppositories, on condoms)
• Effective
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What if we had a complete
HIV toolkit?
Prior to exposure
Point of
transmission
Treatment
• Rights-focused
behaviour change
• Male and female
condoms and lube
• Improved
antiretroviral therapy
• Voluntary
counselling and
testing
• ART to prevent
perinatal
transmission
• Treatment for
opportunistic
infections
• STI screening and
treatment
• Clean injecting
equipment
• Basic care/nutrition
• Preventative
Vaccines
• Vaginal and rectal
microbicides
• Pre-exposure
prophylaxis (PREP)
• Cervical barriers
• Education and
behavior change
• Post-exposure
prophylaxis (PEP)
• Therapeutic
vaccines
• Male circumcision
• Prevention for
positives
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Why vaginal microbicides?
• Women currently have no way to protect
themselves when her partner won’t use a
condom
• Women biologically more vulnerable to HIV
– 2-4 times more likely than men to get HIV from
vaginal sex
• Women may be less able to assert their rights
• Current methods (abstinence, fidelity, and
condom use) often require male consent,
knowledge, or cooperation
www.global-campaign.org
Vaginal Microbicide
Research in 2005
5 products
3 products
10-20 products
Laboratory
Testing
2-6 Years
6 products
Phase 1
(safety)
Phase 2
(safety)
Phase 3
(efficacy)
1 to 6
Months
Up to 2
Years
2 to 4
Years
25 – 40
people
200-400
people
3,000-10,000
people
Simultaneous studies in some cases:
HIV+, penile & rectal safety
10 or more years
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How could
microbicides work?
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Kill/inactivate/immobilize the virus
Boost body’s natural defenses
Prohibit viral entry by blocking fusion
Inhibit viral replication
Create a physical barrier
or some combination of these approaches
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Physiological
Differences
Vagina
Rectum
Most of the epithelium
is 40 cell layers thick
Very fragile epithelium,
1 cell layer thick.
Fewer CD4 cells than
rectum
More inflammatory cells
under surface
(CD4 receptors)
Acidic pH
Alkaline, rather than acidic
pH
Enclosed pouch
Open-ended tube
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Anatomy 101
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Research questions
• Infection – more to learn about anal intercourse
and HIV infection
• Testing - What assays (tests) to measure
impact?
• Distribution – how would it spread?
• Application Methods?
• Dosing – how much, what is acceptable?
• How does rectal shedding of HIV impact risk?
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Laboratory research
To learn more about:
• How HIV infection occurs in the rectum – what
cells are most vulnerable
• The impact of intercourse on rectal tissue
(trauma, inflammation, speed of healing)
• What markers can we look at to determine
impact of a product on the rectum?
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Laboratory research
in action
Dr. Ian McGowan, HPTN 056
University of California/Los Angeles
Goal: To define measurements that can be made
on rectal tissue biopsies that would be of use in
rectal microbicide safety studies.
Repeated measurements on 16 men, and studied
variation based on:
– Time
– Location in the rectum
– Sero status
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Penile Acceptability
Studies
To learn more about…
• How much tissue is likely to be exposed
to a microbicide
• Impact of a product on the penis
www.global-campaign.org
Distribution research
in action:
Dr. Craig Hendrix at Johns Hopkins University in
Baltimore
• Volunteers simulated anal intercourse
• MRI scans done up to five hours after its
release
• Initial studies suggest that semen could travel
up to 60 centimeters
• Showed where a microbicide would be needed
to protect vulnerable tissues
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Behavioral Research
To learn more about…
• Prevalence of anal intercourse for both mean
and women – and how many of these acts
are protected
• Preferences re: formulation and delivery
systems
• Sexual practices that affect microbicide
feasibility
• How much product is acceptable
www.global-campaign.org
Behavioral research
in action:
Alex Carballo-Diéguez, Columbia Univ (NY)
Ken Mayer, Fenway Community Health (Boston)
How much gel is tolerable?
• 18 HIV uninfected men
• Maximum acceptable dose for insertion and
anal intercourse
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Behavioral research
in action:
Alex Carballo-Diéguez and Sigma Research Center
both did surveys of MSM interest in using microbicide
Results:
In San Francisco: 59% heard of microbicides,
25% - 35% might use (depending on stated
effectiveness)
In the UK: 23% had heard of microbicides, 59%
might use
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More vital steps
1. Men and women need education about the
risks of unprotected anal sex
2. Safety trials on rectal application of vaginal
microbicides that are currently in large scale
trials
3. Testing over the counter lubes to see how
safe they are
4. Advocacy for increased research
www.global-campaign.org
Rectal safety trials
on vaginal products
• We won’t know if the first vaginal microbicides are
effective for rectal use
• But we must know if they are safe to put in
the rectum or not
• Because some people will try to use them rectally
• If deemed harmful for the rectum, labels warning
against rectal use are imperative.
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Testing on
over the counter lubes
Drs. Sudol & Phillips at Population Council, New York
• Tested 5 OTC lubes in mice to see if they caused
damage to rectal cells
• KY-Plus (no longer on market) and DeLube caused the
most damage
• Viamore, Vagisil and Astroglide caused some damage
• More research is underway, with findings expected soon.
• Need more research to see if these products cause
damage to human rectal cells
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Advocacy for rectal
microbicides
• Microbicide research is drastically underfunded
• Need for increased funding for both vaginal
and rectal microbicides
– Talk to your government officials
– e.g., U.S. Microbicide Development Act
www.global-campaign.org
Global Campaign for
Microbicides
A worldwide effort co-sponsored by groups
working on
• HIV/AIDS
• reproductive health
• gay health
• women’s empowerment
Working to educate, raise awareness and
generate collective advocacy for increased
political and public investment in
microbicide development
www.global-campaign.org
LifeLube.org
New strategy to raise awareness and
demand among gay men
Three components:
• Internet – http://lifelube.org
• Public presence in forums & conferences
• Media – print, electronic, guerilla!
www.global-campaign.org
International Rectal
Microbicides Working Group
Working Collaboratively:
• Global listserv
• Bi-monthly conference calls
• Developed an advocacy agenda
• To join, contact Jim Pickett, [email protected]
Presence at conferences:
– Microbicides 2006 conference
– Gay Men’s Health Conferences
– Gay and Lesbian Medical
Association annual meeting
www.global-campaign.org
What you can do
Visit www.global-campaign.org or
www.lifelube.org to
• Join the International Rectal Microbicide
Working Group calls and listserve
• Learn more about rectal microbicides
• Sign up for the Global Campaign’s newsletter
• Host a talk on microbicides – this and other
presentations available for download
• Endorse the Global Campaign
www.global-campaign.org