Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tipranavir is a new nonpeptidic protease inhibitor and belongs to the class of 4-hydroxy-5, 6-dihydro-2-pyrones. Chemically, tipranavir is based on coumarin and sulfonamide compounds, amongst others. It exhibits potent and specific activity against both HIV-1 and -2. Tipranavir 500 mg in combination with ritonavir 200 mg twice daily results in optimum viral load reduction and suppresses both wild-type and protease inhibitor-resistant virus. It is metabolized by the cytochrome P4503A4 enzyme and its pharmacokinetic parameters are enhanced when combined with ritonavir. Tipranavir is excreted primarily in the feces, with minimal excretion in urine. In early trials, tipranavir/ritonavir was demonstrated to be safe and well tolerated, with mild gastrointestinal side effects. Preliminary data indicate pharmacokinetic interaction with nucleotide reverse transcriptase inhibitors; however, no dose adjustments are recommended at this time. Virologic response is not adequate when combined with other ritonavir-boosted protease inhibitors, and is currently not recommended. As with other protease inhibitors, tipranavir interacts with fluconazole, atorvastatin, clarithromycin and rifabutin and absorption is reduced when taken with antacids and didanosine (enteric coated formulation). Phase III trials are underway to compare the efficacy of tipranavir/ritonavir with other antiretroviral agents.
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PMID:Tipranavir: a novel second-generation nonpeptidic protease inhibitor. 1575 54

Tipranavir is a non-peptidic HIV-1 protease inhibitor. It binds strongly and selectively, has a favourable resistance profile, and is administered orally twice daily with a subtherapeutic dosage of ritonavir in a 'boosted' regimen (TPV/r) in order to increase its bioavailability. Analysis of clinical isolates from treatment-experienced patients identified the following tipranavir resistance-associated HIV protease mutations: L10V, I13V, K20M/R/V, L33F, E35G, M36I, K43T, M46L, I47V, I54A/M/V, Q58E, H69K, T74P, V82L/T, N83D, I84V. In two large, well designed phase III trials in protease inhibitor-experienced, HIV-infected patients, the RESIST (Randomised Evaluation of Strategic Intervention in multidrug reSistant patients with Tipranavir)-1 and -2 studies, oral TPV/r 500mg/200mg twice daily achieved a significantly better virological response after 24 weeks than standard ritonavir-boosted protease inhibitors. This held true for the proportion of patients achieving a >or=1 log(10) decrease in plasma HIV-RNA levels (viral load) [42% and 41% vs 22% and 15%; both p < 0.0001; primary endpoint] and other virological parameters (the proportion of patients with undetectable viral load and total viral load reduction). In addition, a significantly larger increase in CD4+ cell count was achieved with TPV/r than comparator regimens in these trials. The most common adverse events in clinical trials of tipranavir were gastrointestinal. The incidence of treatment discontinuation because of adverse events in the RESIST trials was 8% (pooled data).
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PMID:Tipranavir: a ritonavir-boosted protease inhibitor. 1606 Jul

Tipranavir is a novel, non-peptidic protease inhibitor, which possesses broad antiviral activity against multiple protease inhibitor-resistant HIV-1. Resistance to this inhibitor however has not yet been well described. HIV was passaged for 9 months in culture in the presence of tipranavir to select HIV with a drug-resistant phenotype. Characterization of the selected variants revealed that the first mutations to be selected were L33F and I84V in the viral protease, mutations which together conferred less than two-fold resistance to tipranavir. At the end of the selection experiments, viruses harbouring 10 mutations in the protease (L10F, I13V, V32I, L33F, M36I, K45I, I54V, A71V, V82L, I84V) as well as a mutation in the CA/SP1 gag cleavage site were selected and showed 87-fold decreased susceptibility to tipranavir. In vitro, tipranavir-resistant viruses had a reduced replicative capacity which could not be improved by the introduction of the CA/SP1 cleavage site mutation. Tipranavir resistant viruses showed cross-resistance to other currently approved protease inhibitors with the exception of saquinavir. These results demonstrate that the tipranavir resistance phenotype is associated with complex genotypic changes in the protease. Resistance necessitates the sequential accumulation of multiple mutations.
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PMID:Selection and characterization of HIV-1 showing reduced susceptibility to the non-peptidic protease inhibitor tipranavir. 1612 17

Four unknown trace impurities (7-10) were observed in the capsule formulation of the HIV drug Tipranavir after prolonged storage at 30 degrees C/70% RH. Extensive NMR and LC/MS analyses revealed the compounds to be covalent adducts between TRIS, an excipient of the formulation, and diastereomeric Tipranavir alcohols formed via slow air oxidation of the drug substance. The structures were ultimately confirmed by total synthesis with final purification by chiral, preparative supercritical fluid chromatography. A novel Favorskii rearrangement to furnish butyrolactones was also uncovered during the synthesis.
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PMID:Structure elucidation and total synthesis of a unique group of trace impurities in Tipranavir drug product. 1614 32

New and potent drugs are urgently needed for the salvage therapy of HIV-infected patients. The protease inhibitors Tipranavir and TMC114, which have high potency against multidrug-resistant viral strains, are the most promising drugs for the near future. How important they will be in salvage therapy cannot be predicted at this time. New points of attack in the viral replication cycle have been defined. Substances belonging to the groups of integrase and maturation inhibitors are in the early stages of clinical development.
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PMID:[New drugs--hope for salvage patients?]. 1638 71

Tipranavir [PNU 140690, tipranivir, Aptivus] is a second-generation HIV dihydropyrone (a sulphonamide derivative), nonpeptidic protease inhibitor (NPPI) discovered by Pharmacia & Upjohn (now Pfizer) in the US. The compound is in development with Boehringer Ingelheim. Tipranavir has potent in vitro activity against a variety of HIV-1 laboratory strains and clinical isolates, including those resistant to ritonavir, as well as HIV-2. Tipranavir has been shown to act synergistically with other antiretroviral agents. The limited bioavailability of the hard gel (and first available) formulation of tipranavir led to the development of a soft capsule formulation that has better oral bioavailability. Pharmacia Corporation (now Pfizer) considers that the resistance profile of tipranavir may be sufficiently unique for it to be effective against protease inhibitor resistant virus. On 16 April 2003, Pharmacia Corporation was acquired by, and merged into, Pfizer. In February 2000, Boehringer Ingelheim acquired exclusive worldwide rights to tipranavir. Tipranavir was launched in the US in mid-2005. In June 2005, the US FDA granted accelerated approval to tipranavir capsules for use in combination treatment, based on 24-week data from ongoing clinical trials. The approved dose is Aptivus 500 mg taken with ritonavir 200 mg, twice daily. Aptivus 250 mg soft gel capsules are expected to be available in the second half of 2005. A submission was made to the FDA in October 2004 seeking accelerated approval. In May 2005, the Antiviral Drugs Advisory Committee of the FDA recommended the approval of tipranavir. The positive recommendation is based on data from the RESIST-1 and RESIST-2 studies. Also in October 2004, Boehringer Ingelheim submitted a Marketing Authorisation Application (MAA) to the European Medicines Agency (EMEA) for tipranavir for the treatment of HIV-1 infection in combination with other antiretroviral agents in patients who are protease inhibitor experienced. In July 2005, the Committee for Medicinal Products for Human Use (CHMP) issued a positive opinion for tipranavir in the European Union. If approved, the drug will be marketed in Europe too under the name Aptivus. Marketing authorisation under exceptional circumstances (accelerated approval) is expected before the end of 2005.A phase III clinical programme (RESIST- Randomised Evaluation of Strategic Intervention in Multi-drug ReSistant Patients with Tipranavir) was launched by Boehringer Ingelheim in February 2003. The RESIST programme consists of two phase III pivotal trials (RESIST 1 and RESIST 2) and two companion trials (study 1182.51 and RESIST 3) available at some sites for even more advanced patients. The trials are designed to further study the efficacy and safety of tipranavir (500 mg) boosted with low-dose (200 mg) ritonavir, taken twice daily, versus a low-dose ritonavir boosted comparator protease inhibitor that is chosen by the patient's physician on the basis of the treatment history and baseline resistance testing. Each patient will also receive an individualised background regimen. Study participants will all be highly treatment-experienced HIV-positive adults. RESIST 1 study enrolled 620 patients in the US, Canada and Australia and RESIST 2 enrolled more than 863 patients in Europe and South America. These trials are now fully recruited. The clinical endpoint for RESIST 1 is at 24 weeks and for RESIST 2, the endpoints are at 16 and 24 weeks. Interim data from RESIST 1 (1182.12) were presented at the 44th Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington, DC, USA, in October 2004. Results from this study show that tipranavir is a viable treatment option for patients who have failed other protease inhibitors. In June 2004, Boehringer Ingelheim announced the expansion of enrolment criteria in the international Compassionate Use Programme to allow broader access to tipranavir for HIV patients in need of new treatment options. All countries participating in the tipranavir phase III programme are eligible to take part in the Compassionate Use programme, which is enrolling patients over the age of 18 years, who are triple-antiretroviral class-experienced with at least two PI-based regimens. In November 2004, Boehringer Ingelheim opened the tipranavir Expanded Access Program (EAP) in the US, following a review of the protocol by the FDA. The programme will provide access to tipranavir for HIV-infected patients (> or =18 years old) who are not enrolled in the ongoing tipranavir clinical studies and who are triple-antiretroviral class-experienced with at least two previous PI-based regimens, and have documented PI-resistance and need tipranavir to construct a viable treatment regimen. Eligibility is not dependent upon viral load or CD4+ cell count. Tiparanvir is also being evaluated in phase II studies for use in paediatric and treatment-naive patient populations. Phase II trials completed in the US have established the clinical activity of tiprananvir in both antiretroviral-naive and -experienced patients with HIV infection. The studies have also shown that tipranavir can be combined with ritonavir for maximal clinical benefit. In its 2003 Annual Report, Boehringer Ingelheim stated that the process- and paediatric- formulation development of tipranavir had been completed.
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PMID:Tipranavir: PNU 140690, tipranivir. 1662 Jan 37

Recent data from clinical trials investigating the efficacy of enfuvirtide, a fusion inhibitor, in treatment-experienced patients have revealed that the addition of enfuvirtide (ENF) to an active boosted protease inhibitor regimen doubles the rate of virological response. At week 48 of the TORO studies, 55% of patients previously naive to and receiving lopinavir/ritonavir (LPV/r) with ENF achieved a viral load of <400 copies/mL compared with 24% of patients treated with LPV/r alone. At week 24 of the RESIST studies, 70% of previously ENF-naive patients who took both ENF and tipranavir/ritonavir (TPV/r) achieved a >or=1 log10 reduction in viral load compared with 37% of such patients treated with TPV/r alone. Similarly, concomitant use of TMC114/ritonavir (TMC114/r) with ENF, compared with TMC114/r alone, increased the number of patients with <50 copies/mL from 46% to 64% in a combined 24-week analysis from the POWER trials. Data from these trials suggest that combining one agent from a new class with a new agent from a previously exposed class offers a greater chance of achieving full virological control than either type of agent alone. Undetectable viraemia should be the primary objective for treatment-experienced patients requiring a switch in therapy, and the present data support the combination of an active boosted protease inhibitor with an agent from a new class (e.g., ENF) for triple-class-experienced patients.
HIV Clin Trials
PMID:Concomitant use of an active boosted protease inhibitor with enfuvirtide in treatment-experienced, HIV-infected individuals: recent data and consensus recommendations. 1679 23

Tipranavir is a novel nonpeptidic protease inhibitor (PI) with activity against wild-type and multidrug-resistant HIV-1 both in vitro and in HIV-infected patients. Tipranavir/ritonavir 500 mg/200 mg administered twice daily for 3 weeks to healthy volunteers produced a median (range) maximum plasma concentration and minimum plasma concentration of 79.1 (34.9-111.7) mg/L and 19.5 (0.43-42.8) mg/L, respectively. Concomitant administration with low-dose ritonavir significantly increases tipranavir plasma concentrations; therefore, the recommended dose is tipranavir 500 mg and ritonavir 200 mg twice daily. Tipranavir is a substrate and inducer of cytochrome P450 3A4 isoenzyme, thus is predisposed to interactions with other agents that are substrates, inducers or inhibitors of this enzyme family. Significant drug-drug interactions have been reported with co-administration of tipranavir/ritonavir and other PIs but not with the non-nucleoside reverse transcriptase inhibitors, efavirenz and nevirapine. Tipranavir/ritonavir 500 mg/200 mg twice daily in combination with an optimised background regimen was more effective than a ritonavir-boosted comparator PI plus an optimised background regimen. The adverse effect profile for tipranavir is similar to other boosted PI regimens and most commonly includes gastrointestinal complaints. Severe adverse events that require close monitoring include hepatotoxicity and lipid abnormalities. Tipranavir retains activity in many highly treatment-experienced patients with a large number of protease mutations. Therefore, this novel PI in combination with ritonavir represents an important new choice in the treatment of multiple-PI-experienced patients.
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PMID:Tipranavir: a novel nonpeptidic protease inhibitor of HIV. 1680 49

Tipranavir is a novel, nonpeptidic protease inhibitor of human immunodeficiency virus type 1 (HIV-1) with activity against clinical HIV-1 isolates from treatment-experienced patients. HIV-1 genotypic and phenotypic data from phase II and III clinical trials of tipranavir with protease inhibitor-experienced patients were analyzed to determine the association of protease mutations with reduced susceptibility and virologic response to tipranavir. Specific protease mutations were identified based on stepwise multiple-regression analyses of phase II study data sets. Validation included analyses of phase III study data sets to determine if the same mutations would be selected and to assess how these mutations contribute to multiple-regression models of tipranavir-related phenotype and of virologic response. A tipranavir mutation score was developed from these analyses, which consisted of a unique string of 16 protease positions and 21 mutations (10V, 13V, 20M/R/V, 33F, 35G, 36I, 43T, 46L, 47V, 54A/M/V, 58E, 69K, 74P, 82L/T, 83D, and 84V). HIV-1 isolates displaying an increasing number of these tipranavir resistance-associated mutations had a reduced phenotypic susceptibility and virologic response to tipranavir. Regression models for predicting virologic response in phase III trials revealed that each point in the tipranavir score was associated with a 0.16-log10 copies/ml-lower virologic response to tipranavir at week 24 of treatment. A lower number of points in the tipranavir score and a greater number of active drugs in the background regimen were predictive of virologic success. These analyses demonstrate that the tipranavir mutation score is a potentially valuable tool for predicting the virologic response to tipranavir in protease inhibitor-experienced patients.
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PMID:Genotypic changes in human immunodeficiency virus type 1 protease associated with reduced susceptibility and virologic response to the protease inhibitor tipranavir. 1692 64

(1) Despite the availability of multidrug antiretroviral therapies, about 3% to 4% of HIV-infected patients exhaust nearly all available treatment options. (2) Tipranavir, an HIV protease inhibitor, is marketed in France for patients with multidrug resistance. (3) Two randomised unblinded trials are currently comparing the tipranavir + ritonavir combination with other protease inhibitors as adjuncts to optimised antiretroviral treatment in 1159 patients selected on the basis of laboratory criteria. Interim results at 48 weeks show that significantly more patients have an undetectable viral load with tipranavir + ritonavir than with other protease inhibitors (22.8% versus 10.2%). Enfuvirtide co-administration seems to reinforce the effect of tipranavir + ritonavir. In contrast, tipranavir does not seem to be more effective than other HIV protease inhibitors to which a given patient's viral population remains sensitive. (4) Tipranavir seems to be associated with higher risks of hepatic disorders, hypertriglyceridaemia, hypercholesterolaemia, and potentially severe bleeding than other protease inhibitors. (5) Tipranavir inhibits the activity of most cytochrome P450 isoenzymes. This creates a strong potential for drug interactions, but clinical experience is limited. (6) Patients on tipranavir must take 2 capsules twice a day. (7) In practice, tipranavir should be saved as a last-resort HIV protease inhibitor.
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PMID:Tipranavir: new drug. HIV protease inhibitor. A last resort. 1716 25


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