Browsing by Author "Waitt, Catriona"

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    72 Weeks Post-Partum Follow-Up of Dolutegravir Versus Efavirenz Initiated in Late Pregnancy (DolPHIN-2): An Open-Label, Randomised Controlled Study
    (The Lancet HIV, 2022) Malaba, Thokozile R.; Nakatudde, Irene; Kintu, Kenneth; Reynolds, Helen; Mrubata, Megan; Seden, Kay; Twimukye, Adelline; Hodel, Eva Maria; Wang, Duolao; Byamugisha, Josaphat; Bokako, Sharon; Waitt, Catriona
    Late initiation of antiretrovirals in pregnancy is associated with increased risk of perinatal transmission and higher infant mortality. We report the final 72-week postpartum results for efficacy and safety of dolutegravir-based compared with efavirenz-based regimens in mothers and infants. DolPHIN-2 was a randomised, open-label trial. Pregnant women in South Africa and Uganda aged at least 18 years, with untreated but confirmed HIV infection and an estimated gestation of at least 28 weeks, initiating antiretroviral therapy in third trimester were eligible for inclusion. Eligible women were randomly assigned (1:1) to receive either dolutegravir-based (50 mg dolutegravir, 300 mg tenofovir disoproxil fumarate, and either 200 mg emtricitabine in South Africa or 300 mg lamivudine in Uganda) or efavirenz-based (fixed dose combination 600 mg tenofovir disoproxil fumarate plus either emtricitabine in South Africa or lamivudine in Uganda) therapy. The primary efficacy outcome was the time to a viral load of less than 50 copies per mL measured at 6, 12, 24, 48, and 72 weeks postpartum with a Cox model adjusting for viral load and CD4 cell count. Safety endpoints were summarised by the number of women and infants with events. This trial is registered with ClinicalTrials.gov, NCT03249181. Between Jan 23 and Aug 15, 2018, 280 women were screened for inclusion, of whom 268 (96%) women were randomly assigned: 133 (50%) to the efavirenz group and 135 (50%) to the dolutegravir group. 250 (93%; 125 [50%] in the efavirenz group and 125 [50%] in the dolutegravir group) women were included in the intention-to-treat analysis of efficacy. Median time to viral load of less than 50 copies per mL was 4·1 weeks (IQR 4·0–5·1) in the dolutegravir group compared with 12·1 weeks (10·7–13·3) in the efavirenz group (adjusted hazard ratio [HR] 1·93 [95% CI 1·5–2·5]). At 72 weeks postpartum, 116 (93%) mothers in the dolutegravir group and 114 (91%) in the efavirenz group had a viral load of less than 50 copies per mL. Of 57 (21%) mothers with a severe adverse event, three (2%) in the dolutegravir group and five (4%) in the efavirenz group were related to the drug (dolutegravir drug-related events were one woman each with suicidal ideation, suicide attempt, herpes zoster meningitis; efavirenz drug-related events were one woman each with suicide attempt and liver cirrhosis, and three people with drug-induced liver injury). Of 136 (56%) infants in whom severe adverse events were recorded, none were related to the study drugs. In addition to the three infant HIV infections detected at birth in the dolutegravir group that have been previously reported, an additional transmission in the efavirenz group occurred during breastfeeding despite optimal maternal viral suppression and serial negative infant tests in the first year of life. Dolutegravir was safe and well tolerated, supporting updated WHO treatment recommendations in pregnant and breastfeeding women. Infant HIV transmissions can occur during breastfeeding despite persistently undetectable maternal viral load highlighting the need for continued infant testing.
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    Drug Interactions between Dolutegravir and Artemether- Lumefantrine or Artesunate-Amodiaquine
    (Antimicrobial agents and chemotherapy, 2018) Walimbwa, Stephen I.; Lamorde, Mohammed; Waitt, Catriona; Kaboggoza, Julian; Else, Laura; Byakika-Kibwika, Pauline; Amara, Alieu; Gini, Joshua; Winterberg, Markus; Chiong, Justin; Tarning, Joel; Khoob, Saye H.
    Across sub-Saharan Africa, patients with HIV on antiretrovirals often getmalaria and need cotreatment with artemisinin-containing therapies. We undertook two pharmacokinetic studies in healthy volunteers, using standard adult doses of artemetherlumefantrine or artesunate-amodiaquine given with 50mg once daily dolutegravir (DTG) to investigate the drug-drug interaction between artemether-lumefantrine or artesunateamodiaquine and dolutegravir. The dolutegravir/artemether-lumefantrine interaction was evaluated in a two-way crossover study and measured artemether, dihydroartemisinin, lumefantrine, and desbutyl-lumefantrine over 264 h. The dolutegravir/artesunate-amodiaquine interaction was investigated using a parallel study design due to long half-life of the amodiaquine metabolite, desethylamodiaquine and measured artesunate, amodiaquine, and desethylamodiaquine over 624 h.
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    Meta-analysis of genome-wide association studies of stable warfarin dose in patients of African ancestry
    (Elsevier Inc, 2024-10-20) Asiimwe, Innocent G; Blockman, Marc; Cavallari, Larisa H; Cohen, Karen; Cupido, Clint; Dandara, Collet; Davis, Brittney H; Jacobson, Barry; Johnson, Julie A; Lamorde, Mohammed; Limdi, Nita A; Morgan, Jennie; Mouton, Johannes P; Muyambo, Sarudzai; Nakagaayi, Doreen; Ndadza, Arinao; Okello, Emmy; Perera, Minoli A; Schapkaitz, Elise; Sekaggya-Wiltshire, Christine; Semakula, Jerome R; Tatz, Gayle; Waitt, Catriona; Yang, Guang; Zhang, Eunice J; Jorgensen, Andrea L; Pirmohamed, Munir
    Warfarin dose requirements are highly variable because of clinical and genetic factors. Although genetic variants influencing warfarin dose have been identified in European and East Asian populations, more work is needed to identify African-specific genetic variants to help optimize warfarin dosing. We performed genome-wide association studies (GWASs) in 4 African cohorts from Uganda, South Africa, and Zimbabwe, totaling 989 warfarin-treated participants who reached stable dose and had international normalized ratios within therapeutic ranges. We also included 2 African American cohorts recruited by the International Warfarin Pharmacogenetics Consortium (n = 316) and the University of Alabama at Birmingham (n = 199). After the GWAS, we performed standard error-weighted meta-analyses and then conducted stepwise conditional analyses to account for known loci in chromosomes 10 and 16. The genome-wide significance threshold was set at P < 5 × 10-8. The meta-analysis, comprising 1504 participants, identified 242 significant SNPs across 3 genomic loci, with 99.6% of these located within known loci on chromosomes 10 (top SNP: rs58800757, P = 4.27 × 10-13) and 16 (top SNP: rs9925964, P = 9.97 × 10-16). Adjustment for the VKORC1 SNP -1639G>A revealed an additional locus on chromosome 2 (top SNPs rs116057875/rs115254730/rs115240773, P = 3.64 × 10-8), implicating the MALL gene, that could indirectly influence warfarin response through interactions with caveolin-1. In conclusion, we reaffirmed the importance of CYP2C9 and VKORC1 in influencing warfarin dose requirements, and identified a new locus (MALL), that still requires direct evidence of biological plausibility.ABSTRACTWarfarin dose requirements are highly variable because of clinical and genetic factors. Although genetic variants influencing warfarin dose have been identified in European and East Asian populations, more work is needed to identify African-specific genetic variants to help optimize warfarin dosing. We performed genome-wide association studies (GWASs) in 4 African cohorts from Uganda, South Africa, and Zimbabwe, totaling 989 warfarin-treated participants who reached stable dose and had international normalized ratios within therapeutic ranges. We also included 2 African American cohorts recruited by the International Warfarin Pharmacogenetics Consortium (n = 316) and the University of Alabama at Birmingham (n = 199). After the GWAS, we performed standard error-weighted meta-analyses and then conducted stepwise conditional analyses to account for known loci in chromosomes 10 and 16. The genome-wide significance threshold was set at P < 5 × 10-8. The meta-analysis, comprising 1504 participants, identified 242 significant SNPs across 3 genomic loci, with 99.6% of these located within known loci on chromosomes 10 (top SNP: rs58800757, P = 4.27 × 10-13) and 16 (top SNP: rs9925964, P = 9.97 × 10-16). Adjustment for the VKORC1 SNP -1639G>A revealed an additional locus on chromosome 2 (top SNPs rs116057875/rs115254730/rs115240773, P = 3.64 × 10-8), implicating the MALL gene, that could indirectly influence warfarin response through interactions with caveolin-1. In conclusion, we reaffirmed the importance of CYP2C9 and VKORC1 in influencing warfarin dose requirements, and identified a new locus (MALL), that still requires direct evidence of biological plausibility. MEDLINE - Academic
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    An open-label, randomized, single intravenous dosing study to investigate the effect of fixed dose combinations of tenofovir/lamivudine or atazanavir/ritonavir on the pharmacokinetics of remdesivir in Ugandan healthy volunteers (RemTLAR)
    (Research Square, 2021) Walimbwa, Stephen Ian; Kaboggoza, Julian Paul; Waitt, Catriona; Byakika-Kibwika, Pauline; D'Avolio, Antonio; Lamorde, Mohammed
    Remdesivir is a novel broad-spectrum antiviral therapeutic with activity against several viruses that cause emerging infectious diseases. The purpose of this study is to explore how commonly utilized antiretroviral therapy (tenofovir disoproxil fumarate /lamivudine [TDF/3TC] and atazanavir/ritonavir [ATV/r]) influence plasma and intracellular concentrations of remdesivir.
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    Relating CYP2B6 Genotype and EFV Resistance Among Women Living With HIV With High Viremia in Uganda: A Nested Cross-Sectional Study.
    (Research Square, 2021) Buzibye, Allan; Wools-Kaloustian, Kara; Olagunju, Adeniyi; Twinomuhwezi, Ellon; Yiannoutsos, Constantin; Owen, Andrew; Neary, Megan; Matovu, Joshua; Banturaki, Grace; Castelnuovo, Barbara; Lamorde, Mohammed; Khoo, Saye; Waitt, Catriona; Kiragga, Agnes
    We investigated the association between CYP2B6 polymorphisms and efavirenz drug resistance among women living with HIV started on anti-retroviral therapy during pregnancy and with high viremia during post-partum. Methods This was a cross sectional study. Women between 6-12 weeks post-partum with viral load >1000 copies/ml were eligible. Sanger sequencing to detect resistant mutations and host genotyping were performed. We categorized efavirenz metabolizer genotype according to the AIDS clinical trials group algorithm as slow, intermediate and extensive; and compared efavirenz resistance among the metabolizer genotypes. Results Over a one-year period (July 2017-July 2018), three hundred and thirty two women were screened of whom 112 (34.8%) had viral load ≥1000 copies/ml of whom 62 had whole blood available for genotyping. Fifty-nine of these women had both viral resistance and human host genotypic results. We observed a higher frequency of efavirenz resistance among slow metabolizers (47% versus 34% in extensive and 28% in intermediate, metabolizers) but due to low numbers, this was not statistically significant. Conclusions Our findings raise the possibility that CYP2B6 polymorphism may contribute to efavirenz drug resistance in women started on antiretroviral therapy during pregnancy and with high viremia in the post-partum period. If confirmed in a larger study, this would have important implications for all patients in sub- Saharan Africa receiving efavirenz and add further support to the changes in World Health Organization policy to switch away from efavirenz as first line antiretroviral therapy in countries with a high prevalence of CYP2B6 polymorphisms.
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    Safety and pharmacokinetics of dolutegravir in pregnant mothers with HIV infection and their neonates: A randomised trial (DolPHIN-1 study)
    (PLoS Med, 2019) Waitt, Catriona; Orrell, Catherine; Walimbwa, Stephen; Singh, Yashna; Kintu, Kenneth; Simmons, Bryony; Kaboggoza, Julian; Sihlangu, Mary; Coombs, Julie- Anne; Malaba, Thoko; Byamugisha, Josaphat; Amara, Alieu; Gini, Joshua; Else, Laura; Heiburg, Christie; Hodel, Eva Maria; Reynolds, Helen; Mehta, Ushma; Byakika-Kibwika, Pauline; Hill, Andrew; Myer, Landon; Lamorde, Mohammed; Khoo, Saye
    The global transition to use of dolutegravir (DTG) in WHO-preferred regimens for HIV treatment is limited by lack of knowledge on use in pregnancy. Here we assessed the relationship between drug concentrations (pharmacokinetics, PK), including in breastmilk, and impact on viral suppression when initiated in the third trimester (T3). Methods and findings In DolPHIN-1, HIV-infected treatment-naïve pregnant women (28–36 weeks of gestation, age 26 (19–42), weight 67kg (45–119), all Black African) in Uganda and South Africa were randomised 1:1 to dolutegravir (DTG) or efavirenz (EFV)-containing ART until 2 weeks post-partum (2wPP), between 9th March 2017 and 16th January 2018, with follow-up until six months postpartum. The primary endpoint was pharmacokinetics of DTG in women and breastfed infants; secondary endpoints included maternal and infant safety and viral suppression. Intensive pharmacokinetic sampling of DTG was undertaken at day 14 and 2wPP following administration of a medium-fat breakfast, with additional paired sampling between maternal plasma and cord blood, breastmilk and infant plasma.
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    Support, not blame: safe partner disclosure among women diagnosed with HIV late in pregnancy in South Africa and Uganda
    (BioMed Central Ltd, 2024-03) Twimukye, Adelline; Alhassan, Yussif; Ringwald, Beate; Malaba, Thokozile; Myer, Landon; Waitt, Catriona; Lamorde, Mohammed; Reynolds, Helen; Khoo, Saye; Taegtmeyer, Miriam
    Abstract HIV partner disclosure rates remain low among pregnant women living with HIV in many African countries despite potential benefits for women and their families. Partner disclosure can trigger negative responses like blame, violence, and separation. Women diagnosed with HIV late in pregnancy have limited time to prepare for partner disclosure. We sought to understand challenges around partner disclosure and non-disclosure faced by women diagnosed with HIV late in pregnancy in South Africa and Uganda and to explore pathways to safe partner disclosure. We conducted in-depth interviews and focus group discussions with pregnant women and lactating mothers living with HIV (n = 109), disaggregated by antenatal care (ANC) initiation before and after 20 weeks of gestation, male partners (n = 87), and health workers (n = 53). All participants were recruited from DolPHIN2 trial sites in Kampala (Uganda) and Gugulethu (South Africa). Topic guides explored barriers to partner disclosure, effects of non-disclosure, strategies for safe disclosure. Using the framework analysis approach, we coded and summarised data based on a socio-ecological model, topic guides, and emerging issues from the data. Data was analysed in NVivo software. Our findings illustrate pregnant women who initiate ANC late experience many difficulties which are compounded by the late HIV diagnosis. Various individual, interpersonal, community, and health system factors complicate partner disclosure among these women. They postpone or decide against partner disclosure mainly for own and baby's safety. Women experience stress and poor mental health because of non-disclosure while demonstrating agency and resilience. We found many similarities and some differences around preferred approaches to safe partner disclosure among female and male participants across countries. Women and male partners preferred healthcare workers to assist with disclosure by identifying the 'right' time to disclose, mentoring women to enhance their confidence and communication skills, and providing professional mediation for partner disclosure and couple testing. Increasing the number of counsellors and training them on safe partner disclosure was deemed necessary for strengthening local health services to improve safe partner disclosure. HIV diagnosis late in pregnancy amplifies existing difficulties among pregnant women. Late ANC initiation is an indicator for the likelihood that a pregnant woman is highly vulnerable and needs safeguarding. Respective health programmes should be prepared to offer women initiating ANC late in pregnancy additional support and referral to complementary programmes to achieve safe partner disclosure and good health.