Principles and recommendations for incorporating estimands into clinical study protocol templates.

Clinical study protocols are the foundation of good clinical studies. Prospective and multidisciplinary collaboration that pays attention to the design of all components of the study protocol can ensure that a clinical study will answer the research questions posed in a reliable manner that is meaningful for decision-makers and patients. The ICH E9(R1) addendum on estimands and sensitivity analysis in clinical trials provides a framework for clinical study planning to ensure alignment between study objectives, design, conduct, and analysis. The estimand or clinical question posed can be regarded as the backbone of the study and the clinical study protocol should reflect estimands accordingly. In practice, stakeholders are still learning how to embrace the estimand framework and how it impacts studies and study documents. In this paper, we anticipate that a protocol structure centred around estimands, or objectives rather than endpoints alone will prevail for all types of studies. To assist sponsors during this paradigm shift, this paper provides discussion and guidance for implementing the estimand framework in protocol templates.

First-line Raltegravir/Emtricitabine/Tenofovir Combination in Human Immunodeficiency Virus Type 2 (HIV-2) Infection: A Phase 2, Noncomparative Trial (ANRS 159 HIV-2).

Background: New options for first-line treatment of human immunodeficiency virus type 2 (HIV-2) infection are needed. We evaluated an integrase inhibitor (raltegravir)-containing regimen. Methods: Antiretroviral therapy (ART)-naive adults with symptomatic infection by HIV-2 only, CD4 count <500 cells/µL or CD4 decrease >50 cells/µL/year over the past 3 years, or a confirmed plasma HIV-2 RNA (pVL) load ≥100 copies/mL were eligible for this noncomparative trial. The composite primary endpoint was survival at 48 weeks without any of the following: CD4 gain from baseline <100 cells/µL, confirmed pVL ≥40 copies/mL from week 24, raltegravir permanent discontinuation, or incident B or C event. HIV-2 ultrasensitive pVL (uspVL) and total DNA were assessed using in-house polymerase chain reaction (PCR) assays. Results: Baseline median CD4 count of 30 enrolled individuals (67% women) was 436 cells/µL (interquartile range [IQR], 314-507 cells/µL); pVL was ≥40 copies/mL in 67% of them, uspVL was ≥5 copies/mL in 92%, and total DNA was >6 copies by PCR in 32%. At week 48, the composite endpoint of success was reached in 40% [95% confidence interval, 22.7%-59.4%]. Failure was mainly (50%) due to CD4 gain <100 cells/µL; uspVL was <5 copies/mL in 87% and total DNA >6 copies by PCR in 12% of participants. Median CD4 gain was 87 cells/µL (IQR, 38-213 cells/µL; n = 28). No serious adverse reactions were reported. Conclusions: Raltegravir-containing ART is a safe option for first-line treatment of HIV-2 infection, yielding a comparable success rate to protease inhibitors. Clinical Trials Registration: NCT 01605890.

Week 96 efficacy of lopinavir/ritonavir monotherapy in virologically suppressed patients with HIV: a randomized non-inferiority trial (ANRS 140 DREAM).

Background: Sparing of antiretroviral drug classes could reduce the toxicity and cost of maintenance treatment for HIV infection. Objectives: To evaluate the non-inferiority of efficacy and the safety of lopinavir/ritonavir (r) monotherapy versus a single-tablet regimen of efavirenz, emtricitabine and tenofovir (EFV/FTC/TDF) over 2 years. Methods: Adults on stable ART with plasma HIV-1 RNA viral load <50 copies/mL for the past 12 months and no documented treatment failure were randomized to receive either lopinavir/r or EFV/FTC/TDF for 2 years. The primary endpoint was the proportion of patients without treatment failure at week 96 (viral load <50 copies/mL at week 96, confirmed at week 98), without study treatment discontinuation, a new AIDS-defining illness, or death. Results: In the ITT analysis, the primary endpoint was reached by, respectively, 64% and 71% of patients in the lopinavir/r (n = 98) and EFV/FTC/TDF arms (n = 97), yielding a difference of -6.8% (lower limit of the 95% two-sided CI: -19.9%). Sanger and UltraDeep sequencing showed the occurrence of PI mutations in the lopinavir/r arm (n = 4) and of NNRTI and/or NRTI mutations in the EFV/FTC/TDF arm (n = 2). No unexpected serious clinical events occurred. Conclusions: Lopinavir/r monotherapy cannot be considered non-inferior to EFV/FTC/TDF. PI resistance rarely emerged in the lopinavir/r arm and did not undermine future PI options. Two years of lopinavir/r monotherapy had no deleterious clinical impact when compared with EFV/FTC/TDF.

Preservation of Lymphopoietic Potential and Virus Suppressive Capacity by CD8+ T Cells in HIV-2-Infected Controllers.

Compared with HIV-1, HIV-2 infection is characterized by a larger proportion of slow or nonprogressors. A better understanding of HIV-2 pathogenesis should open new therapeutic avenues to establish control of HIV-1 replication in infected patients. In this study, we studied the production of CD8(+) T cells and their capacity for viral control in HIV-2 controllers from the French ANRS CO5 HIV-2 cohort. HIV-2 controllers display a robust capacity to support long-term renewal of the CD8(+) T cell compartment by preserving immune resources, including hematopoietic progenitors and thymic activity, which could contribute to the long-term maintenance of the CD8(+) T cell response and the avoidance of premature immune aging. Our data support the presence of HIV-2 Gag-specific CD8(+) T cells that display an early memory differentiation phenotype and robust effector potential in HIV-2 controllers. Accordingly, to our knowledge, we show for the first time that HIV-2 controllers possess CD8(+) T cells that show an unusually strong capacity to suppress HIV-2 infection in autologous CD4(+) T cells ex vivo, an ability that likely depends on the preservation of host immune resources. This effective and durable antiviral response probably participates in a virtuous circle, during which controlled viral replication permits the preservation of potent immune functions, thus preventing HIV-2 disease progression.