Tom Van De Casteele

Publications (7)22.85 Total impact

• Article: Virological analysis of once-daily and twice-daily darunavir/ritonavir in the ODIN trial of treatment-experienced patients.

  Erkki Lathouwers, Guy De La Rosa, Tom Van de Casteele, Benny Baeten, Frank Tomaka, Sandra De Meyer, Gaston Picchio
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  ABSTRACT: BACKGROUND: The aim of this analysis was to characterize viral resistance in the Phase III, randomized ODIN trial, which demonstrated non-inferiority of once-daily darunavir/ritonavir (DRV/r) 800/100 mg to DRV/r 600/100 mg twice daily, each combined with an optimized background regimen in treatment-experienced patients with no DRV resistance-associated mutations (RAMs) at screening. METHODS: Virological failure (VF) was defined as never achieving or losing confirmed virological suppression after week 12, with patients being classed as 'never suppressed' (never achieved HIV-1 RNA<50 copies/ml) or 'rebounders' (achieved two consecutive HIV-1 RNA<50 copies/ml but then ≥50 copies/ml). Phenotypes and genotypes of plasma HIV-1 viruses, using population-based sequencing and Antivirogram(®), were determined at screening/baseline and on samples from VFs with HIV-1 RNA≥50 copies/ml. RESULTS: Mean baseline HIV-1 RNA was 4.16 log10 copies/ ml and 53.9% of patients were protease inhibitor (PI)-experienced at enrolment. VF rate was similar in both arms. A similar proportion of virologically failing patients in both arms developed PI RAMs (11.7% versus 9.5%, respectively) or nucleoside reverse transcriptase inhibitor RAMs (6.7% versus 7.1%). One patient with VF (once-daily arm) developed four primary PI mutations, three of which were also DRV RAMs. This patient was also the only VF to lose susceptibility to DRV. Loss of susceptibility to other PIs (once daily 3.4%; twice daily 0%) and nucleoside reverse transcriptase inhibitors (once daily 13.6%; twice daily 9.8%) in VF patients was infrequent and comparable between treatment arms. CONCLUSIONS: These analyses showed once-daily DRV/r 800/100 mg was associated with similar rates of VF and emergence of resistance as DRV/r 600/100 mg twice daily in treatment-experienced patients with no DRV RAMs.
  Antiviral therapy 04/2013; · 3.16 Impact Factor
• Article: Week 96 efficacy, virology and safety of darunavir/r versus lopinavir/r in treatment-experienced patients in TITAN.

  Dénes Bánhegyi, Christine Katlama, Clóvis Arns da Cunha, Stefan Schneider, Anita Rachlis, Cassy Workman, Sandra De Meyer, Ann Vandevoorde, Tom Van De Casteele, Frank Tomaka
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  ABSTRACT: Long-term potent activity of antiretrovirals is essential for HIV-1-infected, treatment-experienced patients. TITAN (TMC114/r In Treatment-experienced pAtients Naive to lopinavir) compared Week-96 efficacy and safety of darunavir/ritonavir (DRV/r) versus lopinavir/ritonavir (LPV/r). Treatment-experienced, LPV-naive, HIV-1-infected patients were randomised to DRV/r 600/100 mg bid or LPV/r 400/100 mg bid plus optimised background regimen (≥ 2 NRTIs/NNRTIs). 595 patients were enrolled (mean baseline HIV-1 RNA: 4.30 log10 copies/mL; median CD4 count: 232 cells/mm3). At Week 96, more DRV/r than LPV/r patients achieved HIV-1 RNA < 400 copies/mL (66.8% versus 58.9% [intent-to-treat (ITT)/time-to-loss of virological response (TLOVR)], estimated difference 8.7%, 95% confidence interval [CI]: 0.7-16.7), demonstrating the primary endpoint of non-inferiority of DRV/r (p < 0.001); the difference in response was statistically significant (p = 0.034). For the secondary efficacy parameter (HIV-1 RNA < 50 copies/mL) at Week 96, response to DRV/r was 60.4% versus 55.2% for LPV/r (ITT-TLOVR), estimated difference 5.8%, 95% CI: -2.3-13.9. Virological failure (VF; HIV-1 RNA > 400 copies/mL) with DRV/r (13.8%) was nearly half that with LPV/r (25.6%). Discontinuations due to adverse events were 8.1% for both DRV/r and LPV/r. Treatment-related grade 2-4 diarrhoea was 8.1% (DRV/r) versus 15.2% (LPV/r). Increases in triglycerides and total cholesterol were less pronounced with DRV/r. At 96 weeks, noninferiority (HIV-1 RNA < 400 copies/mL) of DRV/r over LPV/r was maintained; the difference in response was statistically significant. VF rate and treatment-related grade 2-4 diarrhoea were lower with DRV/r versus LPV/r.
  Current HIV research 01/2012; 10(2):171-81. · 1.98 Impact Factor
• Article: Week 48 analysis of once-daily vs. twice-daily darunavir/ritonavir in treatment-experienced HIV-1-infected patients.

  Pedro Cahn, Jan Fourie, Beatriz Grinsztejn, Sally Hodder, Jean-Michel Molina, Kiat Ruxrungtham, Cassy Workman, Tom Van De Casteele, Piet De Doncker, Erkki Lathouwers, Frank Tomaka
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  ABSTRACT: ODIN (Once-daily Darunavir In treatment-experieNced patients) was a phase III, 48-week, open-label study comparing once-daily vs. twice-daily darunavir/ritonavir (DRV/r) in treatment-experienced patients with no DRV resistance-associated mutations (RAMs) at screening. Patients with no DRV RAMs and receiving stable HAART for at least 12 weeks were stratified by HIV-1 RNA (≤ or > 50 000 copies/ml) and randomized to once-daily DRV/r 800/100 mg or twice-daily DRV/r 600/100 mg and an optimized background regimen (≥2 nucleoside reverse transcriptase inhibitors). Primary objective was to demonstrate noninferiority of once-daily vs. twice-daily DRV/r in confirmed virologic response (HIV-1 RNA < 50 copies/ml) at week 48. Five hundred and ninety patients received once-daily (n = 294) or twice-daily (n = 296) DRV/r. Mean baseline HIV-1 RNA was 4.16 log10 copies/ml; median CD4 cell count was 228 cells/μl; and 53.9% had previously used at least one protease inhibitor. At week 48, 72.1% of once-daily and 70.9% of twice-daily patients achieved HIV-1 RNA less than 50 copies/ml (intent-to-treat/time-to-loss of virologic response). The difference in response between once-daily and twice-daily arms was 1.2% (95% confidence interval -6.1 to 8.5%; P < 0.001), establishing noninferiority of once-daily DRV/r versus twice-daily DRV/r. Median CD4 cell count increase was 100 (once-daily) and 94 cells/μl (twice-daily). Virologic failure rate was low and similar for both arms; only one patient (once-daily arm) developed primary protease inhibitor mutations. Once-daily DRV/r had a lower incidence of grade 2-4 triglyceride increases (5.2 vs. 11.0%, P < 0.05). Once-daily DRV/r 800/100 mg was noninferior in virologic response to twice-daily DRV/r 600/100 mg at 48 weeks in treatment-experienced patients with no DRV RAMs, and with a more favorable lipid profile. These findings support use of once-daily DRV/r in this population.
  AIDS (London, England) 02/2011; 25(7):929-39. · 4.91 Impact Factor
• Article: Virological characterization of patients failing darunavir/ritonavir or lopinavir/ritonavir treatment in the ARTEMIS study: 96-week analysis.

  Erkki Lathouwers, Sandra De Meyer, Inge Dierynck, Tom Van de Casteele, Ludo Lavreys, Marie-Pierre de Béthune, Gaston Picchio
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  ABSTRACT: In the Phase III ARTEMIS Trial, treatment-naive patients received once-daily darunavir/ritonavir (DRV/r) 800/100 mg (n = 343) or lopinavir/ritonavir (LPV/r) 800/200 mg (total daily dose; n = 346) plus fixed-dose tenofovir disoproxil fumarate/emtricitabine. The primary outcome measure was non-inferiority of DRV/r versus LPV/r (HIV type-1 [HIV-1] RNA<50 copies/ml). Here, a detailed 96-week resistance analysis is presented. Virological failures (VFs) were defined as patients who had lost (rebounders) or who had never achieved (never suppressed) HIV-1 RNA < 50 copies/ml after week 12. Genotypic and phenotypic determinations were performed on plasma samples with HIV-1 RNA ≥ 50 copies/ml. The end point was defined as the last on-treatment visit with available genotype and/or phenotype. The VF rate was significantly lower in DRV/r (12%, n = 40) versus LPV/r patients (17%, n = 59; P = 0.0437). Among DRV/r patients, 24 rebounded and 16 were never suppressed, whereas among LPV/r patients, 33 rebounded and 26 were never suppressed. Transient HIV-1 RNA increases (≥ 50 copies/ml) occurred in 50% (n = 12) DRV/r and 48% (n = 16) LPV/r rebounders; these viral levels returned to undetectable by end point without any changes to the study regimen. No major (primary) protease inhibitor (PI) resistance-associated mutations (RAMs) developed in VFs with an available genotype at baseline and end point, and almost all developing minor PI RAMs were polymorphic. At end point, all VFs with available phenotypes at baseline and end point remained susceptible to all PIs, including study PIs. The VF rate was lower with DRV/r than LPV/r. The findings of this resistance analysis confirmed the lack of development of major PI RAMs and the preservation of phenotypic susceptibility to all PIs in patients with VF.
  Antiviral therapy 01/2011; 16(1):99-108. · 3.16 Impact Factor
• Article: Pharmacokinetics of darunavir/ritonavir and rifabutin coadministered in HIV-negative healthy volunteers.

  Vanitha Sekar, Ludo Lavreys, Tom Van de Casteele, Cindy Berckmans, Sabrina Spinosa-Guzman, Tony Vangeneugden, Martine De Pauw, Richard Hoetelmans
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  ABSTRACT: The drug-drug interaction between rifabutin (RFB) and darunavir/ritonavir (DRV/r) was examined in a randomized, three-way crossover study of HIV-negative healthy volunteers who received DRV/r 600/100 mg twice a day (BID) (treatment A), RFB 300 mg once a day (QD) (treatment B), and DRV/r 600/100 mg BID plus RFB 150 mg every other day (QOD) (treatment C). The sequence of treatments was randomized, and each treatment period lasted 12 days. Full pharmacokinetic profiles were determined for DRV, ritonavir, and RFB and its active metabolite, 25-O-desacetylrifabutin (desRFB), on day 13. The DRV and ritonavir areas under the plasma concentration-time curve from zero to 12 h (AUC(12h)) increased by 57% and 66%, respectively, in the presence of RFB. The RFB exposure was comparable between treatment with RFB QD alone (treatment B) and treatment with DRV/r plus RFB QOD (treatment C); however, based on least-square means ratios, the minimum plasma concentration (C(min)) increased by 64% and the maximum plasma concentration (C(max)) decreased by 28%, respectively. The exposure (AUC within the dosage interval and at steady state [AUC(τ)]) to desRFB was considerably increased (by 881%) following treatment with DRV/r/RFB. The exposure to the parent drug plus the metabolite increased 1.6-fold in the presence of DRV/r. Adverse events (AEs) were more commonly reported during combined treatment (83% versus 44% for RFB and 28% for DRV/r); similarly, grade 3-4 AEs occurred in 17% versus 11% and 0%, respectively, of volunteers. Eighteen of 27 volunteers (66.7%) prematurely discontinued the trial; all volunteers discontinuing for safety reasons (n = 9) did so during RFB treatment phases. These results suggest that DRV/r may be coadministered with RFB with a dose adjustment of RFB to 150 mg QOD and increased monitoring for RFB-related AEs. Based on the overall safety profile of DRV/r, no dose adjustment of DRV/r is considered to be warranted. Given the safety profile seen with the combination of RFB with a boosted protease inhibitor in this and other studies, it is not recommended to conduct further studies with this combination in healthy volunteers.
  Antimicrobial Agents and Chemotherapy 10/2010; 54(10):4440-5. · 4.84 Impact Factor
• Article: In vitro susceptibility and virological outcome to darunavir and lopinavir are independent of HIV type-1 subtype in treatment-naive patients.

  Inge Dierynck, Sandra De Meyer, Erkki Lathouwers, Carline Vanden Abeele, Tom Van De Casteele, Sabrina Spinosa-Guzman, Marie-Pierre de Béthune, Gaston Picchio
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  ABSTRACT: The effect of HIV type-1 (HIV-1) subtype on in vitro susceptibility and virological response to darunavir (DRV) and lopinavir (LPV) was studied using a broad panel of primary isolates, and in recombinant clinical isolates from treatment-naive, HIV-1-infected patients in the Phase III trial, AntiRetroviral Therapy with TMC114 ExaMined In naive Subjects (ARTEMIS). Patients received DRV/ritonavir (DRV/r) 800/100 mg once daily (n=343) or LPV/ritonavir (LPV/r) 800/200 mg total daily dose (n=346), plus a fixed daily dose of emtricitabine and tenofovir disoproxil fumarate. DRV demonstrated high antiviral activity against a broad panel of HIV-1 major group (M) and outlier group (O) primary isolates in peripheral blood mononuclear cells, with a median 50% effective concentration (EC(50)) of 0.52 nM. Most (61%) patients in ARTEMIS harboured HIV-1 subtype B; other prevalent subtypes were C (13%) and CRF01_AE (17%); 9% harboured other subtypes. Median EC(50) values (interquartile range) for DRV were 1.79 nM (1.3-2.6) for subtype B, 1.12 nM (0.8-1.4) for C and 1.27 nM (1.0-1.7) for CRF01_AE. Virological response to DRV/r (HIV-1 RNA<50 copies/ml [intent-to-treat, time-to-loss of virological response algorithm]) was 81%, 87% and 85% for patients with subtype B, C and CRF01_AE infections, respectively. Similar results were observed in the LPV/r treatment group. In vitro susceptibility to DRV was comparable across HIV-1 subtypes in a broad panel of primary isolates and in recombinant clinical isolates. Once daily DRV/r 800/100 mg and LPV/r 800/200 mg were highly effective in ARTEMIS irrespective of the HIV-1 subtype studied, confirming their broad anti-HIV-1 activity.
  Antiviral therapy 01/2010; 15(8):1161-9. · 3.16 Impact Factor
• Article: Effect of baseline characteristics on the efficacy and safety of once-daily darunavir/ ritonavir in HIV-1-infected, treatment-naïve ARTEMIS patients at week 96.

  Jan Fourie, Jason Flamm, Amalia Rodriguez-French, Don Kilby, Pere Domingo, Adriano Lazzarin, Juan Ballesteros, Nestor Sosa, Tom Van De Casteele, Ralph DeMasi, Sabrina Spinosa-Guzman, Ludo Lavreys
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  ABSTRACT: ARTEMIS demonstrated significantly greater efficacy of once-daily darunavir/ritonavir (DRV/r) 800/100 mg versus lopinavir/ritonavir 800/200 mg (total daily dose) in treatment-naïve, HIV-1-infected patients at week 96. The influence of baseline characteristics on efficacy and safety was analyzed in DRV/r patients. Patients received once-daily DRV/r plus fixed-dose tenofovir/emtricitabine. Week 96 efficacy and safety data were analyzed by gender (males, n=239; females, n=104), age (≤30, n=115; 31-45, n=175; >45, n=53), race (Asian, n=44; Black, n=80; Caucasian/White, n=137; Hispanic, n=77), and hepatitis B and/or C virus coinfection (n=43). Week 96 virologic response rates (HIV-1 RNA<50 copies/mL) were as follows: gender: 79% for both males and females; age: 72% (≤30), 81% (31-45), and 89% (>45); race: 96% (Asian), 71% (Black), 77% (Caucasian/White), and 79% (Hispanic); coinfection status: 72% (coinfected) and 80% (non-coinfected). The incidence of treatment-related adverse drug reactions (ADRs) and laboratory abnormalities were comparable across gender, age, and race subgroups. Coinfected patients had a higher incidence of liver-related ADRs than non-coinfected patients. DRV/r 800/100 mg qd is an effective, well-tolerated treatment option for treatment-naïve patients of different gender, age, race, or coinfection status.
  HIV Clinical Trials 12(6):313-22. · 1.64 Impact Factor