UK-CAB August 2003

Conference Feedback

For 6th UK-CAB

8th August 2003

Simon Collins

HIV i-Base

UK-CAB August 2003

Online abstracts

• XII Resistance Workshop, Mexicohttp://www.mediscover.net/journals.cfm

• 5th Lipodystrophy Workshop, Parishttp://www.intmedpress.com

• 2nd IAS Conference, Parishttp://ww2.aegis.org/conferences/2ndIASHIVPT/ias.pdf

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UK-CAB August 2003

XII Resistance Meeting

• Resistance meeting usually based on research more than clinical studies, but an indication of the importance of research is that most discoveries that lead to changes in treatment practice were first presented as early data to these annual meetings.

• Only around 120 scientists attend [+ very few community – this isn’t so good…]

• Every scientist presents a paper – and every paper is very interesting

• The next studies were all new, and relevant to clinical care

UK-CAB August 2003

Clinical Studies

• Transmission of drug resistance• Co-infection, reinfection, superinfection• Single dose nevirapine (75% MTCT)• Effectiveness of resistance tests• Cross resistance between NNRTIs• Resisdual activity of drugs• Tenofovir resistance

UK-CAB August 2003

Primary Resistance (CATCH)

• Evaluated primary drug resistance in Europe and Israel • Isolates from over 1600 patients were genotyped• Overall rate of genotypic resistance was 9.6%• NRTIs had the highest rate (6.9%), followed by NNRTIs (2.6%)

and PIs (2.2%); 1.7% of isolates with multiclass resistance• 11% seroconvertors and 8% chronic infection • The most common mutations are significant in conferring

reduced susceptibility to agents such as:– Zidovudine and stavudine (M41V, T215F/Y)– NNRTIs (K103N) – PIs (M46I, G48V, I84V)

• Higher rate of primary resistance in subtype B vs non-B isolates (11.3% vs 3.3%, P < .001)

Mexico, Abstract 17

UK-CAB August 2003

UK transmission

• Data from UK HIV Drug Resistance Database (community initiated collaboration)

• 9,800 tests from 7000 patients. Collected 1996 - Mar 03

yr PI NNRTI Key mutations in naive

• 96-98 26% 20% 10%• 99-01 32% 40% 16%• 01-03 27% 48% 17%

• BHIVA: – Resistance test before treatment– Resistance test on diagnosis

Pillay et al Abstract 124

UK-CAB August 2003

Implications of transmitted Rx

• Doesn’t revert to wild type

- Little et al, K103N to K median 196 days (95CI: 153-238

No reversion of PI in 64, 191, 342 days

only 1/10 revert at 1019dy (Abs 115)

- Delauguerre et al - 2 cases sexual transmission out to 2 years in cellular reservoirs (Abs 80)

- Coral - 9/46 seroconvertors with resistance progressed at similar rates - therefore NOT less fit (Abs81)

UK-CAB August 2003

Co-infection, reinfection and superinfection

• important to recognise that all occur, and the differences between them

• Co-infection = either infected with two different viruses at the same timeOR infected with a second virus before your immune system reacts to the first infection (ie prior to seroconversion - this may be re-infection(re-infection usually requires clearing of a first infection, which doesn’t happen with HIV)

• Superinfection = second infection AFTER first infection is established

• Frequency is unknown, BUT effect of drug resistance is likely as in other cases

UK-CAB August 2003

Example of superinfection

• Daar et al, SubB MDR, vl to 1000 at mo 2, then superinfected with WT

[Phylogenetic analysis and viral diversity]

• Burger et al, Kenyan woman, SubA 1986, Sub A/C 1997 (IAS, Abs 71)

• Manigart et al, 2/147 women, Burkino Faso both showed evidence of second separate infection at time of viral increase (IAS 72)

UK-CAB August 2003

Phylogenetic tree (RTI)

• Example of

Phylogentic tree

For RTI sequence

UK-CAB August 2003

Single-dose nevirapine

• HIVNET 012 - single dose of NVP to mother at onset of labour and single dose to infant - 21/111 (19%) Rx at 6-8 wks

• Now 25/33 (76%) Rx at wk 2• Reversed to WT by wk 8 in 12/27 (44%)• Highlights limitations of Rx testing, that

reversion occurs, but also likely to be archived in pro-viral DNA

• Implications for future treatment

Mexico, Abstract 78, 79

UK-CAB August 2003

NNRTI X-resistance

• Sometimes hear of people cycling NNRTIs even though not recommended

• Resistance tests can show 181 and not 103• Mellors et al, 50/216 NNRTI-exp but without

resistance has same response to those with evidence of NNRTI resistance (Abs 134)

• Lecossier et al, with selective PCR found 103N in 5/16 samples with previously only 181 by regular tests (Abs 143)

UK-CAB August 2003

Resisdual activity of drugs

• NNRTIs have no activity with 103 etc

• RTIs may continue activity (d4T) (Abs 133)

• 3TC withdrawal in small study lead to increased viremia (Abs 140)

• Also see Deeks, 10th CROI Abs 188

• CAUTION: sanctuary compartments

UK-CAB August 2003

Tenofovir

• New drug, few failures in trials

• K65R in 8/36 failures (20%)

• X-Rx with abacavir and some pipeline

• May occur less with d4T or AZT-based (but IAS Abs 42 - TZV+TDF included AZT with K65R)

UK-CAB August 2003

5th Lipodystrophy Workshop

• Annual meeting - this year 350 delegates• Includes community places and press

registrations• Often at least half is basic science including in

vitro and animal studies• Posters usually include clinical research

including other side effects (LA, bone, diarrhoea etc)

• Six key lectures online: (in next few weeks) - including atherosclerosis, role of adipose tissue and adipocytokines in insulin resistance, pharmacogenomics)

UK-CAB August 2003

5th Lipodystrophy Workshop

• Link between adipocytes, mitochondrial depletion, HIV and AZT/d4T treatment now clear

• Reversal of fat loss with switch of d4T or AZT to abacavir, and benefits continue out to 2 yrs

• Intima Media Thickness (IMT) and heart disease• Reduced BMD in women - increased monitoring

recommended• Rosigliatazone reverses lipoatrophy in people

with HIV and insulin resistance• Fat transfer of broen fat led to swollen cheeks• Treatment interruption - option used in practice

UK-CAB August 2003

Morphology of adipose tissue

• Several groups are reporting very exciting and important work looking closely at fat cells and comparing HIV-negative, HIV-positive untreated, and by exposure to different treatment (ie d4T, AZT and other nukes or PI)

Caron, Bastard et al, Lancet 2003]

Nolan, Mallal et al, AIDS 2003; 17(9):1329-1338

• The Australian group (Nolan et al) also reported looking at mitochondrial differences in fat cells form these different groups, and showed correlation of damage to treatment:

d4T use > AZT use > HIV+ naïve > HIV-negative

UK-CAB August 2003

Morphology of adiposetissue

Fat cells from HIV-positive and nucleoside-exposed patients are not plump full cells - differences include that they are smaller and shorter-lived.

Nolan, Malal et al, AIDS 2003; 17(9):1329-1338

Adipose tissue morphology (light microscopy). (a) Normal adipose tissue histology. (b) Typical histology associated withsubcutaneous fat wasting. Line arrows indicate blood vessels. Block arrow indicates a lipogranuloma.

UK-CAB August 2003

Lipoatrophic tissue

Lipo workshop Summary, J Cappeau, IAS, Paris

UK-CAB August 2003

Comparison of adipocyte mtDNA copy number HIV-neg, HIV negative; HIV+ART-, HIV positive, antiretroviral therapy naive ZDV, zidovudine; d4T, stavudine. Nolan, Mallal et al AIDS 2003; 17(9):1329-1338

UK-CAB August 2003

Switch d4T to abacavir

Continued increase in limb fat out to 2 years following switch from AZTor d4T to abacavir (Carr et al for MITOX Study, IAS LB18)

UK-CAB August 2003

MITOX study

• Serial DEXA and CT showed +0.39kg limb fat at 24 wks

• Mean f/u 102 wks with 74/111 with imaging to wk 104: +1.26kg

• Greater increases associated with lower BMD, shorter duration of AZT pre-study (p=0.024) and shorter use of d4T on-study (p=0.004)

Carr et al Abstract 16

UK-CAB August 2003

Reduced BMD in women

• Dexa in 84 HIV+ vs 63 HIV-• Oesteopenia in 54% vs 30% (p=0.004)• Osteoporosis in 10% vs 5% (p=0.27)• BMD correlated with body mass and total

fat (p<0.001)• Markers of bone metabolism showed

increased resorbtion• Monitoring important for HIV+ women

Grinspoon et al Abstract 24

UK-CAB August 2003

Severe efavirenz side effects

• Small study - 6/200 pts from Kings referred to specialist unit

• Included suicide ideation and severe depression, homicide ideation in one case, suicide attempted in two cases

• Symptoms resolved when EFV stopped• 2/6 with no previous psychiatric history• As first line UK therapy, awareness of 2-3% risk is

important for this small group of people

Allin et al Abstract 129

UK-CAB August 2003

Further Reading

Reports by Mark Mascolini:(Each approx 30 pages)

• XII Resistance Workshop, Mexicohttp://www.ias.se/pdf/625.pdf

• 2nd IAS Meetinghttp://www.ias.se/pdf/632.pdf

UK-CAB August 2003

SIMBA Trial (Stopping Infection from Mother-to-child via Breastfeeding in Africa)

• HIV-infected pregnant women received zidovudine (ZDV) +didanosine (ddI) from the 36th week of gestation until 1 week after delivery

• 397 infants were randomized to receive once-daily lamivudine (3TC) or nevirapine (NVP) until 1 month after breastfeeding was stopped; breast milk was the only source of nutrition to the infant

• Overall, there were 30 cases of HIV infection (7.6% transmission); 24 cases resulted from intrauterine transmission; 3 cases were probably due to transmission during delivery

• Of the remaining 370 infants at risk of becoming infected, only 3 (0.8%) became HIV-positive

• 3TC and NVP were effective (Gd 3/4 toxicty apprx 15% & 20% resp.)• Potential to protect 250,000+ infants from HIV each year

IAS. Abstract LB7.

Most important IAS study…?

UK-CAB August 2003

UK-CAB.6

• 8th August 2003

• Training sessions:

Conference Feedback Sessions

• Afternoon:

GSK