PHARMACOKINETICS & ANTIRETROVIRUS RESISTANCE TESTING

描述(由申请人提供)：本申请描述了一种整合药代动力学(PK)和病毒表型药物敏感性(IC50)信息的方法，以帮助临床医生为其治疗经验丰富的艾滋病毒感染患者选择最佳抢救治疗方案。从文献中收集了多个基于双酶抑制剂(PI)或非核苷类似物(NNRTI)方案的PK参数。为每种方案创建了具有内置可变性的PK模型，并用于模拟每种方案的100条浓度-时间曲线。这提供了在平均患者群体中可以预期的广泛的低谷水平。PI或NNRTI的IC50针对血浆蛋白结合进行了校正，并与模拟谷值范围(Craig)进行了比较。在使用这种称为概率估计的方法时，可以确定每种药物达到蛋白质结合校正IC50(PBICs0)以上的低谷水平的可能性。这种方法根据达到所需血浆浓度的可能性对每种可能的方案进行排名。这种方法直接适用于临床，不需要测量药物水平。假设是PK和表型信息的整合最大限度地提高了抗逆转录病毒治疗在有治疗经验的受试者的管理中的好处。病毒耐药性是一个连续体；病毒易感性的特定倍数变化并不一定意味着药物将无效，必须考虑患者的可达到的药物浓度。这项应用的具体目的是：1)前瞻性地验证概率估计方法，方法是将每个参与者在基线时的PI浓度达到PBIC95以上的估计概率与他们随后在第4周接受基于概率估计方法选择的抗逆转录病毒方案时进行的密集药代动力学评估得出的实际智商相关联；以及2)通过将60名中等耐药水平的受试者分成两组，在一项为期16周的前瞻性“概念验证”试点研究中评估短期病毒学反应。一组患者将使用表型试验选择后续的抢救方案，以供临床医生指导，另一组患者将使用概率估计方法，该方法固有地包括表型和药物药代动力学，用于临床医生指导。所有受试者将在第4周接受密集的PK评估，并在16周内每4周追踪一次，以评估短期病毒学应答。这项工作的长期目标是：(1)允许将这些观察结果扩展到更大、控制良好的临床试验中，并根据这里产生的I期研究结果进行优化的样本量计算；以及(2)最终将这些发现扩展到治疗经验较少的患者，以证明其广泛的临床适用性。

DESCRIPTION (provided by applicant): This application describes a method of integrating pharrnacokinetic (PK) and viral phenotypic drug susceptibility (IC50) information to assist clinicians in choosing optimal regimens for salvage therapy of their treatment-experienced HIV-infected patients. PK parameters from multiple dual protease inhibitor (PI)-based or non-nucleoside analog (NNRTI) regimens were collected from the literature. PK models with built-in variability were created for each regimen and used to simulate 100 concentration-time curves for each regimen. This provides a wide range of trough levels that can be expected in the average patient population. The IC50 for a PI or NNRTI is corrected for plasma protein binding and compared with the range of simulated trough levels (Craig). In using this approach, called Probability Estimations, it is possible to determine the probability of achieving trough levels above the protein-binding corrected IC50 (PBICs0) for each drug. This method ranks each possible regimen based on the likelihood of achieving the desired plasma concentrations. This approach is directly applicable to the clinic, and does not require measurement of drug levels. The hypothesis is that integration of PK and phenotypic information maximizes the benefit of antiretroviral therapy in the management of treatment-experienced subjects. Viral drug resistance is a continuum; a certain fold-change in virus susceptibility does not necessitate a drug will be inactive and achievable drug concentrations in the patient must be considered. The specific aims of this application are: 1) to prospectively validate the Probability Estimations method by correlating the estimated probability of achieving PI trough concentrations above the PBIC95 for each participant at baseline with their subsequently measured actual IQ derived from an intensive pharmacokinetic evaluation at week 4 while receiving an antiretroviral regimen selected based on the Probability Estimations approach; and 2) to assess short-term virologic response in a prospective, 16-week "proof-of-concept" pilot study by enrolling 60 subjects with moderate-level drug resistance into two randomized arms. One arm will have their subsequent salvage regimen chosen using a phenotypie test for clinician guidance, the other arm will use the Probability Estimations approach that inherently includes phenotyping plus drug pharmacokinetics for clinician guidance. All subjects will undergo an intensive PK evaluation at week 4, and followed every 4 weeks for 16 weeks to assess short-term virologic response. The long-term objectives of this work are: (1) to allow expansion of these observations into a larger, well-controlled clinical trial with optimized sample size calculations based on the phase I study results generated here; and (2) to ultimately expand these findings into less treatment-experienced patients to demonstrate its widespread clinical applicability.