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Crixivan (Indinavir Sulfate) - Summary



CRIXIVAN® (indinavir sulfate) is an inhibitor of the human immunodeficiency virus (HIV) protease. CRIXIVAN Capsules are formulated as a sulfate salt and are available for oral administration in strengths of 100, 200, and 400 mg of indinavir (corresponding to 125, 250, and 500 mg indinavir sulfate, respectively).

CRIXIVAN in combination with antiretroviral agents is indicated for the treatment of HIV infection.

This indication is based on two clinical trials of approximately 1 year duration that demonstrated: 1) a reduction in the risk of AIDS-defining illnesses or death; 2) a prolonged suppression of HIV RNA.

Description of Studies

In all clinical studies, with the exception of ACTG 320, the AMPLICOR HIV MONITOR assay was used to determine the level of circulating HIV RNA in serum. This is an experimental use of the assay. HIV RNA results should not be directly compared to results from other trials using different HIV RNA assays or using other sample sources.

Study ACTG 320 was a multicenter, randomized, double-blind clinical endpoint trial to compare the effect of CRIXIVAN in combination with zidovudine and lamivudine with that of zidovudine plus lamivudine on the progression to an AIDS-defining illness (ADI) or death. Patients were protease inhibitor and lamivudine naive and zidovudine experienced, with CD4 cell counts of ≤200 cells/mm3. The study enrolled 1156 HIV-infected patients (17% female, 28% Black, 18% Hispanic, mean age 39 years). The mean baseline CD4 cell count was 87 cells/mm3. The mean baseline HIV RNA was 4.95 log10 copies/mL (89,035 copies/mL). The study was terminated after a planned interim analysis, resulting in a median follow-up of 38 weeks and a maximum follow-up of 52 weeks. Results are shown in Table 4 and Figures 1 & 2.

Table 4: ACTG 320
Number (%) of Patients with AIDS-defining Illness or Death
Endpoint IDV+ZDV+L
IDV = Indinavir, ZDV = Zidovudine, L = Lamivudine
HIV Progression or Death 35 (6.1) 63 (10.9)
Death 1 10 (1.7) 19 (3.3)

1 The number of deaths is inadequate to assess the impact of Indinavir on survival.

Study ACTG 320: Figure 1 - Indinavir Protocol ACTG 320 Zidovudine Experienced Plasma Viral RNA - Proportions Below 400 copies/mL Study ACTG 320: Figure 2 - ACTG 320 Zidovudine Experienced CD4 Cell Counts - Mean Change from Baseline

Study 028, a double-blind, multicenter, randomized, clinical endpoint trial conducted in Brazil, compared the effects of CRIXIVAN plus zidovudine with those of CRIXIVAN alone or zidovudine alone on the progression to an ADI or death, and on surrogate marker responses. All patients were antiretroviral naive with CD4 cell counts of 50 to 250 cells/mm3. The study enrolled 996 HIV-1 seropositive patients [28% female, 11% Black, 1% Asian/Other, median age 33 years, mean baseline CD4 cell count of 152 cells/mm3, mean serum viral RNA of 4.44 log10 copies/mL (27,824 copies/mL)]. Treatment regimens containing zidovudine were modified in a blinded manner with the optional addition of lamivudine (median time: week 40). The median length of follow-up was 56 weeks with a maximum of 97 weeks. The study was terminated after a planned interim analysis, resulting in a median follow-up of 56 weeks and a maximum follow-up of 97 weeks. Results are shown in Table 5 and Figures 3 and 4.

Table 5: Protocol 028
Number (%) of Patients with AIDS-defining Illness or Death
Endpoint IDV+ZDV
HIV Progression or Death 21 (6.3) 27 (8.1) 62 (18.7)
Death 1 8 (2.4) 5 (1.5) 11 (3.3)

1 The number of deaths is inadequate to assess the impact of Indinavir on survival.

Study 028: Figure 3 - Indinavir Protocol 028 Zidovudine Naive Viral RNA - Proportions Below 500 Copies/mL in Serum Study 028: Figure 4 - Indinavir Protocol 028 Zidovudine Naive CD4 Cell Counts - Mean Change from Baseline

Study 035 was a multicenter, randomized trial in 97 HIV-1 seropositive patients who were zidovudine-experienced (median exposure 30 months), protease-inhibitor- and lamivudine-naive, with mean baseline CD4 count 175 cells/mm3 and mean baseline serum viral RNA 4.62 log10 copies/mL (41,230 copies/mL). Comparisons included CRIXIVAN plus zidovudine plus lamivudine vs. CRIXIVAN alone vs. zidovudine plus lamivudine. After at least 24 weeks of randomized, double-blind therapy, patients were switched to open-label CRIXIVAN plus lamivudine plus zidovudine. Mean changes in log10 viral RNA in serum, the proportions of patients with viral RNA below 500 copies/mL in serum, and mean changes in CD4 cell counts, during 24 weeks of randomized, double-blinded therapy are summarized in Figures 5, 6, and 7, respectively. A limited number of patients remained on randomized, double-blind treatment for longer periods; based on this extended treatment experience, it appears that a greater number of subjects randomized to CRIXIVAN plus zidovudine plus lamivudine demonstrated HIV RNA levels below 500 copies/mL during one year of therapy as compared to those in other treatment groups.

Study 035: Figure 5 - Indinavir Protocol 035 Zidovudine Experienced Viral RNA - Mean Log10 Change from Baseline in Serum Study 035: Figure 6 - Indinavir Protocol 035 Zidovudine Experienced Viral RNA - Proportions Below 500 Copies/mL in Serum Study 035: Figure 7 - Indinavir Protocol 035 Zidovudine Experienced CD4 Cell Counts - Mean Change from Baseline

Genotypic Resistance in Clinical Studies

Study 006 (10/15/93-10/12/94) was a dose-ranging study in which patients were initially treated with CRIXIVAN at a dose of <2.4 g/day followed by 2.4 g/day. Study 019 (6/23/94-4/10/95) was a randomized comparison of CRIXIVAN 600 mg every 6 hours, CRIXIVAN plus zidovudine, and zidovudine alone. Table 6 shows the incidence of genotypic resistance at 24 weeks in these studies.

Table 6: Genotypic Resistance at 24 Weeks
Treatment Group Resistance
to IDV
n/N 1
to ZDV
IDV — —
    <2.4 g/day 31/37 (84%) —
      2.4 g/day 9/21 (43%) 1/17 (6%)
IDV/ZDV 4/22 (18%) 1/22 (5%)
ZDV 1/18 (6%) 11/17 (65%)

1 N - includes patients with non-amplifiable virus at 24 weeks who had amplifiable virus at week 0.

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Published Studies Related to Crixivan (Indinavir)

Indinavir-loaded pH-sensitive microparticles for taste masking: toward extemporaneous pediatric anti-HIV/AIDS liquid formulations with improved patient compliance. [2009]
The aim of this work was to develop indinavir pediatric anti-HIV/AIDS formulations enabling convenient dose adjustment, ease of oral administration, and improved organoleptic properties by means of the generation of drug-loaded microparticles made of a polymer that is insoluble under intake conditions and dissolves fast in the stomach in order to completely release the active agent...

Effect of omeprazole on the plasma concentrations of indinavir when administered alone and in combination with ritonavir. [2008.03.01]
PURPOSE: The effects of omeprazole on indinavir when administered alone or in combination with ritonavir were evaluated... CONCLUSION: The AUC of indinavir was substantially decreased in healthy volunteers who received omeprazole 20 or 40 mg daily for seven days before the administration of a single 800-mg dose of indinavir. Concomitant administration of ritonavir 200 mg with indinavir in participants receiving omeprazole led to a significant increase in the AUC of indinavir.

Association of efavirenz hypersusceptibility with virologic response in ACTG 368, a randomized trial of abacavir (ABC) in combination with efavirenz (EFV) and indinavir (IDV) in HIV-infected subjects with prior nucleoside analog experience. [2008.01]
CONCLUSION: Premature treatment discontinuations in the ABC arm and the presence of EFV-HS HIV variants in this patient population likely made it difficult to detect a benefit of adding ABC to EFV+IDV. In addition, L74V, when combined with K103N+L100I, may confer a selective advantage to the virus that is independent of its effects on nucleoside resistance.

Lack of indinavir-associated nephrological complications in HIV-infected adults (predominantly women) with high indinavir plasma concentration in Abidjan, Cote d'Ivoire. [2007.01]
To report the tolerance of indinavir combined with ritonavir (IDV/r 800/100 mg) twice daily (bid) in sub-Saharan African HIV-infected adults... There was a surprising lack of nephrological side effects during the 6 months of follow-up, supporting the hypothesis that nephrological tolerance of IDV might be higher in sub-Saharan African individuals than in Americans or Europeans.

Pharmacogenetic characteristics of indinavir, zidovudine, and lamivudine therapy in HIV-infected adults: a pilot study. [2006.08.01]
OBJECTIVE: The aim of the study was to investigate relationships among indinavir, lamivudine-triphosphate, and zidovudine-triphosphate pharmacokinetics and pharmacodynamics with polymorphisms in CYP3A5, MDR1, MRP2, MRP4, BCRP, and UGT1A1 genes. STUDY DESIGN: Retrospective pilot investigation among 33 subjects who participated in a randomized pharmacological study of indinavir, lamivudine, and zidovudine...

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Clinical Trials Related to Crixivan (Indinavir)

Treatment With Indinavir and Chemotherapy for Advanced Classical Kaposi's Sarcoma [Active, not recruiting]
The purpose of this study is to determine the clinical response to daily Indinavir oral administration in association with a conventional chemotherapy based on cycles of systemic Vinblastine +/- Bleomycin in patients affected by advanced classical (non HIV-associated) Kaposi's sarcoma

A Study on the Safety and Effectiveness of Twice-Daily Nelfinavir Plus Twice-Daily Indinavir Plus Efavirenz in HIV-Positive Patients Who Have Never Taken Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) or Protease Inhibitors [Completed]
Indinavir is usually taken three times a day. The purpose of this study is to see if it is safe and effective to take indinavir only twice a day plus nelfinavir (also taken twice a day) and efavirenz (taken once a day).

A Pharmacokinetic (PK) Study of a Combination of Indinavir, Ritonavir, and Amprenavir [Completed]
When individuals who are infected with HIV are started on treatment with HIV medications, the effect of these drugs only lasts for a limited period of time, often because of development of drug resistance by the HIV virus. When this happens, such patients have to be switched to different combinations of HIV medications. However, since the availability of new HIV drugs that are active against resistant virus is limited, HIV care providers are resorting to curtail medications that contain three or more protease inhibitors (PIs). The reason for this is Norvir (ritonavir), a PI that has the ability to boost or increase the blood levels of other PIs in a way that can sometimes overcome the resistance of HIV virus. In addition, it may be more difficult for the virus to overcome two or more drugs with high blood levels, than it is to overcome just one. For these reasons, many clinicians are now using Norvir in combination with two other PIs, including Crixivan (indinavir) plus Lexiva (fosamprenavir), for treating patients who have been exposed to many other HIV medications. While this may be the case, researchers also know that when two or more PIs are combined, the effects each drug may have on the blood level of other drugs could be different. For example, researchers know from some recent studies that the combination of Norvir, Lexiva, and Kaletra, another PI, leads to an unacceptably low level of both Kaletra and Lexiva. Because researchers can not always assume that when multiple HIV medications are combined, the levels will remain high enough to be effective, the investigators think it will always be reasonable that, before any combination of drugs are used on HIV-infected patients, the effect a combination has on the levels of each of the drugs in the combination should be investigated. AIMS: The aim of this pilot study therefore is to examine the blood levels of Crixivan, Lexiva, and Norvir when these three drugs are used together as part of a combination treatment for HIV infection. METHODS: Fifteen (15) HIV-infected volunteers already being treated with a Crixivan and Norvir containing regimen will be recruited from the Grady Infectious Disease Clinic (IDP). Lexiva will be added to this regimen for 5 days, at the end of which participants will be admitted to the Grady General Clinical Research Center (GCRC) where blood samples will be collected at 9 different time points over 12 hours for measurement of blood drug levels. Pharmacokinetic Analysis: The blood concentrations of Crixivan, Lexiva, and Norvir will be measured by a special technique known as reverse-phase high-performance liquid chromatography with ultraviolet detection. Statistical Analysis: The blood level information will be summarized by a statistical method. The researchers will then compare the levels of Lexiva in this combination with historically published levels of Lexiva in a study of Lexiva plus Norvir; and that of Crixivan in a study of Crixivan plus Norvir. A difference of 30% or more in drug levels between this study and historical reports will be considered a significant difference.

Study of How Indinavir (an Anti-HIV Drug) and Rifabutin (a Drug Used to Treat MAC, an HIV-Associated Disease) Interact in HIV-Positive and HIV-Negative Adults [Completed]
The purpose of this study is to evaluate the safety of giving indinavir and rifabutin at the same time (simultaneously) vs 4 hours apart (staggered) to HIV-positive and HIV-negative adults. It is important to determine which medications for HIV-associated diseases, such as Mycobacterium avium complex (MAC) disease, can be given safely and effectively with anti-HIV drugs. Indinavir and rifabutin have been given simultaneously in the past with good results. This study seeks to examine if staggering the doses will make the 2 drugs more effective. HIV-negative volunteers are used in this study to examine the effect of rifabutin on indinavir and the effect of staggered rifabutin doses. The effect of rifabutin on the drug activity of indinavir is evaluated in HIV-positive patients.

A Comparison of Epivir Plus Crixivan Combined With Zerit or Retrovir in HIV-Infected Patients Who Have Never Taken Anti-HIV Drugs [Completed]
To evaluate the tolerance, and comparative virologic and immunologic effects of the two combination regimens.

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Reports of Suspected Crixivan (Indinavir) Side Effects

Pulmonary Hypertension (3)Palpitations (3)Dizziness (3)Death (2)T-Lymphocyte Count Decreased (2)Dementia (1)Pain (1)Drug Interaction (1)Hemiparesis (1)Pupils Unequal (1)more >>

Page last updated: 2009-10-20

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