The TLR7 agonist vesatolimod induced a modest delay in viral rebound in HIV controllers after cessation of antiretroviral therapy

Toll-like receptor 7 (TLR7) agonists, in combination with other therapies, can induce sustained control of simian-human immunodeficiency virus (SHIV) or simian immunodeficiency virus (SIV) in nonhuman primates. Here, we report the results of a randomized, double-blind, placebo-controlled phase 1b clinical trial of an oral TLR7 agonist, vesatolimod, in HIV-1-infected controllers on antiretroviral therapy (ART). We randomized participants 2:1 to receive vesatolimod (n = 17) or placebo (n = 8) once every other week for a total of 10 doses while continuing on ART. ART was then interrupted, and the time to viral rebound was analyzed using the Kaplan-Meier method. Vesatolimod was associated with induction of immune cell activation, decreases in intact proviral DNA during ART, and a modest increase in time to rebound after ART was interrupted. The delayed viral rebound was predicted by the lower intact proviral DNA at the end of vesatolimod treatment (13 days after the final dose). Inferred pathway analysis suggested increased dendritic cell and natural killer cell cross-talk and an increase in cytotoxicity potential after vesatolimod dosing. Larger clinical studies will be necessary to assess the efficacy of vesatolimod-based combination therapies aimed at long-term control of HIV infection.

Vesatolimod, a Toll-like Receptor 7 Agonist, Induces Immune Activation in Virally Suppressed Adults Living With Human Immunodeficiency Virus-1

BACKGROUND

Treatment with vesatolimod, an investigational, oral, toll-like receptor 7 (TLR7) agonist, leads to sustained viral remission in some non-human primates when combined with anti-envelope antibodies or therapeutic vaccines. We report results of a Phase Ib study evaluating safety, pharmacokinetics, and pharmacodynamics of vesatolimod in adults living with human immunodeficiency virus (HIV)-1.

METHODS

In this double-blind, multicenter, placebo-controlled trial, participants on antiretroviral therapy with screening plasma HIV-1 RNA levels <50 copies/mL were randomized (6:2) to receive 6-10 doses of vesatolimod (1-12 mg) or matching placebo orally every other week in sequential dose-escalation cohorts. The primary study objectives included establishing the safety and virologic effects of vesatolimod (change from baseline in plasma HIV-1 RNA). Pharmacokinetics and pharmacodynamic/immunologic activity were assessed as secondary objectives.

RESULTS

A total of 48 individuals were randomly assigned to vesatolimod (n = 36) or placebo (n = 12). Vesatolimod was generally well tolerated, with no study drug-related serious adverse events or adverse events leading to study drug discontinuation. There were no statistically significant changes from baseline in plasma HIV-1 RNA in the vesatolimod groups, compared to placebo.Vesatolimod plasma exposures increased dose proportionally; consistent responses in cytokines, interferon-stimulated gene expression, and lymphocyte activation were observed with increasing dose levels above 4 mg. Peak elevations 24 hours after receipt of a 6 mg dose were >3.9-fold higher for interferon gamma-induced protein 10 (IP-10), interleukin-1 receptor antagonist (IL-1RA), interferon-inducible T-cell alpha chemoattractant (ITAC) when compared to baseline values.

CONCLUSIONS

Vesatolimod was well tolerated at doses ranging from 1 to 12 mg. Immune stimulation was observed at doses above 4 mg, providing rationale for future combination trials in people living with HIV.

CLINICAL TRIALS REGISTRATION

NCT02858401.

Multi-stakeholder consensus on a target product profile for an HIV cure

Developing a cure for HIV is a global priority. Target product profiles are a tool commonly used throughout the drug development process to align interested parties around a clear set of goals or requirements for a potential product. Three distinct therapeutic modalities (combination therapies, ex-vivo gene therapy, and in-vivo gene therapy) for a target product profile for an HIV cure were identified. Using a process of expert face-to-face consultation and an online Delphi consultation, we found a high degree of agreement regarding the criteria for the optimum target product profile. Although the minimum attributes for a cure were debated, the broad consensus was that an acceptable cure need not be as safe and effective as optimally delivered antiretroviral therapy. An intervention that successfully cured a reasonable fraction of adults would be sufficient to advance to the clinic. These target product profiles will require further discussion and ongoing revisions as the field matures.

561. Safety of Remdesivir vs Standard Care in Patients with Moderate Covid-19

Background

Remdesivir (RDV) has been shown to shorten recovery time and was well tolerated in patients with severe COVID-19. Here we report safety of RDV in patients with moderate COVID-19.

Methods

We conducted an open-label, phase 3 trial (NCT04252664) in hospitalized patients with confirmed SARS-CoV-2 infection, evidence of pulmonary infiltrates, and oxygen saturation >94% on room air. Patients were randomly assigned to receive RDV (5 or 10 days) or standard of care (SOC). RDV was dosed intravenously at 200 mg on day 1, 100 mg daily thereafter. Adverse events (AEs) and laboratory abnormalities were evaluated through the day 11 data cut; safety data through day 28 will be presented at the meeting.

Results

584 patients were randomized and treated (5d RDV: n=191; 10d RDV, n=193; SOC: n=200). Baseline characteristics were balanced among groups; median (range) age was 57y (12-95y), 39% were female and 19% Black, 39% had arterial hypertension, 15% hyperlipidemia, 11% asthma. Briefly, across both the 5d and 10d arms, RDV was well tolerated with a similar rate of Grade 3 or 4 AEs and fewer SAEs compared to SOC (Table). AEs more common with RDV vs SOC included nausea, headache, and hypokalemia. Overall, across the 3 arms, incidence of AEs leading to discontinuation and death were low and no clinically relevant changes in laboratory parameters were observed. In addition, median changes in renal and liver function tests from baseline were not statistically significant between the RDV 5d and RDV 10d groups compared to the SOC only group at d14 (Table 1).

Table 1.

Conclusion

RDV given for 5d or 10d was well tolerated in patients with moderate COVID-19. No clinically significant safety signals were observed with RDV vs SOC.

Disclosures

Gerard J. Criner, MD, Gilead Sciences Inc. (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator) Gerard J. Criner, MD, NO DISCLOSURE DATA Mi Young Ahn, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Gregory Huhn, MD, Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator)Janssen (Grant/Research Support)Proteus (Grant/Research Support)US National Institutes of Health (Grant/Research Support)Viiv Healthcare (Grant/Research Support) Aruna Subramanian, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Carlos Lumbreras, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Stefan Schmiedel, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Robert H. Hyland, MD, Gilead Sciences Inc. (Employee, Shareholder) Vithika Suri, PhD, Gilead Sciences Inc. (Employee, Shareholder) Huyen Cao, MD, Gilead Sciences Inc. (Employee, Shareholder) Hongyuan Wang, PhD, Gilead Sciences Inc. (Employee, Shareholder) Devi SenGupta, MD, Gilead Sciences Inc. (Employee, Shareholder) Anand Chokkalingam, PhD, Gilead Sciences (Employee) Anu Osinusi, MD, Gilead Sciences (Employee) Diana M. Brainard, MD, Gilead Sciences (Employee) Yao-Shen Chen, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Yao-Shen Chen, MD, NO DISCLOSURE DATA Huldrych Günthard, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) D Jose Sanz-Moreno, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Judith A. Aberg, MD, Theratechnology (Consultant) Emanuele Nicastri, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Owen Tak-Yin Tsang, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Owen Tak-Yin Tsang, MD, NO DISCLOSURE DATA

72. Remdesivir vs Standard Care in Patients with Moderate covid-19

Background

Remdesivir (RDV) shortens time to recovery time in patients with severe COVID-19. Its effect in patients with moderate COVID-19 remains unclear.

Methods

We conducted an open-label, phase 3 trial (NCT04252664) involving hospitalized patients with confirmed SARS-CoV-2 infection, evidence of pulmonary infiltrates, and oxygen saturation >94% on room air. Patients were randomly assigned 1:1:1 to receive up to 5d or 10d of RDV with standard of care (SoC), or SoC alone; patients could be discharged prior to completing per-protocol assigned treatment duration. RDV was dosed intravenously at 200 mg on d1, 100 mg daily thereafter. Patients were evaluated daily while hospitalized, and via telephone if discharged. The primary endpoint was clinical status on d11 assessed on a 7-point ordinal scale. Results regarding the primary endpoint are expected to be published before IDWeek 2020; we plan to present d28 results at the meeting.

Results

In total, 584 patients underwent randomization and started their assigned treatment (191, 5d RDV; 193, 10d RDV; 200, SoC). By d11, ³ 2 point improvement on the ordinal scale occurred in 70% of patients in the 5d arm, 65% in the 10d arm, and 61% in the SoC arm. Patients in the 5d RDV arm were significantly more likely to have an improvement in clinical status than those receiving SoC (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.09–2.48; P=0.017); OR of improvement for the 10d RDV arm compared to SoC was 1.31 (95% CI, 0.88–1.95]; p=0.183). This improvement in the 5-day arm over the SOC arm was noted from d6 through d11. We observed a peak of discharges corresponding with the assigned treatment duration of RDV, with increased discharges at d6 in the 5-day arm and at d11 in the 10-day arm. A worsening of clinical status of ≥ 1 point in the ordinal scale was observed more commonly in the SoC am (n=19, 10%) versus the 5d RDV (n=7, 4%) and 10d RDV (n=9, 5%).

Conclusion

RDV for up to 5 days was superior to SoC in improving the clinical status of patients with moderate COVID-19 by d11. We will report d28 outcomes at the meeting.

Disclosures

Francisco M. Marty, MD, Allovir (Consultant)Amplyx (Consultant)Ansun (Scientific Research Study Investigator)Avir (Consultant)Cidara (Scientific Research Study Investigator)F2G (Consultant, Scientific Research Study Investigator)Kyorin (Consultant)Merck (Consultant, Grant/Research Support, Scientific Research Study Investigator)New England Journal of Medicine (Other Financial or Material Support, Honorarium for Video)Regeneron (Consultant, Scientific Research Study Investigator)ReViral (Consultant)Scynexis (Scientific Research Study Investigator)Symbio (Consultant)Takeda (Scientific Research Study Investigator)United Medical (Consultant)WHISCON (Scientific Research Study Investigator) Prashant Malhotra, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Robert L. Gottlieb, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Karen T. Tashima, MD, Bristol-Myers Squibb (Research Grant or Support)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator)GlaxoSmithKline (Research Grant or Support)Merck (Research Grant or Support)Tibotec (Research Grant or Support)Viiv Healthcare (Research Grant or Support) Massimo Galli, MD, Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Other Financial or Material Support, Personal fees) Louis Yi Ann Chai, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Devi SenGupta, MD, Gilead Sciences Inc. (Employee, Shareholder) Robert H. Hyland, MD, Gilead Sciences Inc. (Employee, Shareholder) Hongyuan Wang, PhD, Gilead Sciences Inc. (Employee, Shareholder) Lijie Zhong, PhD, Gilead Sciences Inc. (Employee, Shareholder) Huyen Cao, MD, Gilead Sciences Inc. (Employee, Shareholder) Anand Chokkalingam, PhD, Gilead Sciences (Employee) Anu Osinusi, MD, Gilead Sciences (Employee) Diana M. Brainard, MD, Gilead Sciences (Employee) Michael Brown, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Ane Josune Goikoetxea, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Mamta Jain, MD, Gilead Sciences Inc. (Scientific Research Study Investigator, Research Grant or Support)GlaxoSmithKline (Advisor or Review Panel member)Janssen (Research Grant or Support)Merck (Research Grant or Support) David Shu Cheong Hui, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Enos Bernasconi, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Christoph Spinner, MD, AbbVie (Advisor or Review Panel member, Other Financial or Material Support, Travel)Bristol-Myers Squibb (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Other Financial or Material Support, Travel)Janssen (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel)MSD (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel)Viiv Healthcare (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel)

557. Impact of Concomitant Hydroxychloroquine Use on Safety and Efficacy of Remdesivir in Moderate COVID-19 Patients

Background

Remdesivir (RDV) has been shown to shorten recovery time and was well tolerated in patients with severe COVID-19. Hydroxychloroquine (HQN) is an experimental treatment for COVID-19. Effects of coadministration of HQN with RDV have not been studied and are relevant given the long half-life (~22 days) of HQN. We report the impact of concomitant HQN and RDV use on clinical outcomes and safety in patients with moderate COVID-19.

Methods

We enrolled hospitalized patients with confirmed SARS-CoV-2 infection, oxygen saturation >94% on room air, and radiological evidence of pneumonia. Patients were randomized 1:1:1 to receive 5d or 10d of intravenous RDV once daily plus standard of care (SoC), or SoC only. We compared patients on concomitant HQN (HQN^pos) vs not (HQN^neg). Clinical recovery was evaluated using Cox proportional hazards. Covariate adjustment included age, sex, race, region, symptom duration, oxygen support status and obesity. Recovery and adverse events (AEs) were assessed through death, discharge, or d14.

Results

Of 584 patients, 199 (34%) received HQN (5d RDV: n=57 [30%]; 10d RDV, n=49 [25%]; SoC: n=93 [47%]). Through median follow-up of 13d (range 1-41d), HQN^pos patients on 5d or 10d RDV had a lower recovery rate (adjusted HR [95% CI] 0.78 [0.59, 1.03], p=0.09) with longer median time to recovery (8 vs 6 days) compared to HQN^neg. HQN^pos compared to HQN^neg patients in 5d RDV showed a trend of reduced recovery rate (HR: 0.69 [0.45,1.04], p=0.080); such an effect was not observed in 10d RDV or SoC (Table 1). More HQN^pos than HQN^neg patients had AEs in RDV (5/10d) or SoC arms evaluated separately, and all arms combined. This difference was significant for AEs and SAEs for all arms combined after covariate adjustment (Table 2).

Table 1.

Table 2.

Conclusion

In moderate COVID-19 patients, concomitant HQN may delay recovery on RDV and showed no impact on recovery with SoC alone. The AE profile of HQN^pos patients was worse than that observed for HQN^neg patients, regardless of RDV treatment.

Disclosures

Jose Ramon Arribas, MD, Alexa (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Gilead Sciences Inc. (Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Janssen (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Merck (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Viiv Healthcare (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees) Jose Ramon Arribas, MD, NO DISCLOSURE DATA Arun J. Sanyal, MD, AbbVie (Consultant)Akarna (Shareholder)Amarin (Consultant)Ardelyx (Consultant)Astra Zeneca (Consultant, Research Grant or Support)Boehringer (Consultant)Bristol Myers Squibb (Research Grant or Support)Conatus (Consultant)Cumberland (Research Grant or Support)Durect (Shareholder)Elsevier (Other Financial or Material Support, Royalties)Exhalenz (Shareholder)Fibrogen (Consultant)Genfit (Shareholder)Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Research Grant or Support)Haemoshear (Shareholder)Indalo (Shareholder)Intercept (Research Grant or Support)Jannsen (Consultant)Lilly (Consultant)Malinckrodt (Research Grant or Support)Merck (Research Grant or Support)Nimbus (Consultant)Nitto Denko (Consultant)Novartis (Consultant)Pfizer (Consultant)Salix (Consultant)Sanyal Biotechnology (Employee, Shareholder, Other Financial or Material Support, President)Shire (Research Grant or Support)Takeda (Consultant)Tiziana (Shareholder)Tobira (Consultant)UptoDate (Other Financial or Material Support, Royalties)Zafgen (Consultant) Bum Sik Chin, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Bum Sik Chin, MD, NO DISCLOSURE DATA Shirin Kalimuddin, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Stefan Schreiber, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Emon Elboudwarej, PhD, Gilead Sciences Inc. (Employee, Shareholder) Yuan Tian, PhD, Gilead Sciences Inc. (Employee, Shareholder) Robert H. Hyland, MD, Gilead Sciences Inc. (Employee, Shareholder) Devi SenGupta, MD, Gilead Sciences Inc. (Employee, Shareholder) Anand Chokkalingam, PhD, Gilead Sciences (Employee) Anu Osinusi, MD, Gilead Sciences (Employee) Diana M. Brainard, MD, Gilead Sciences (Employee) Christoph Lübbert, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Chien Boon Lye, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Chien Boon Lye, MD, NO DISCLOSURE DATA Judith A. Aberg, MD, Theratechnology (Consultant) Enrique Navas Elorza, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Karen T. Tashima, MD, Bristol-Myers Squibb (Research Grant or Support)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator)GlaxoSmithKline (Research Grant or Support)Merck (Research Grant or Support)Tibotec (Research Grant or Support)Viiv Healthcare (Research Grant or Support) Mark McPhail, MD, Gilead Sciences Inc. (Scientific Research Study Investigator)

73. Geographical Disparities in Clinical Outcomes of Severe COVID-19 Patients Treated with Remdesivir

Background

Remdesivir (RDV), a RNA polymerase inhibitor with potent in vitro activity against SARS-CoV-2, is the only treatment with demonstrated efficacy in shortening the duration of COVID-19. Here we report regional differences in clinical outcomes of severe COVID-19 patients treated with RDV, as part of an open-label, randomized phase-3 trial establishing RDV treatment duration.

Methods

Hospitalized patients with oxygen saturation ≤94%, a positive SARS-CoV-2 PCR in the past 4 days and radiographic evidence of pneumonia were randomized 1:1 to receive 5d or 10d of intravenous RDV. We compared d14 clinical outcomes of patients from different geographical areas, as measured by mortality rates, change in clinical status from baseline (BL) on a 7-point ordinal scale and change in O2 requirements from BL. Based on previous analyses in compassionate use data showing region as an important predictor of outcome, Italy was examined separately from other regions.

Results

397 patients were treated with RDV, of which 229 (58%) were in the US, 77 (19%) Italy, 61 (15% in Spain), 12 (3%) Republic of Korea, 9 (2%) Singapore, 4 (1%) Germany, 4 (1%) Hong Kong and 1 (< 1%) Taiwan. BL clinical status was worse in Italy compared to other regions (72% vs 17% requiring high-flow oxygen delivery or higher), and Italian patients were more likely to be male than patients from other regions (69% vs 63%). Overall results showed 5d RDV was as effective as 10d. Mortality at d14 was higher in Italy (18%) compared to all other countries except Italy (7%). Similarly, clinical improvement at d14, measured as ≥2-point increase in the ordinal scale, was lower in Italian patients (39%) compared to all other countries combined (64%). (Fig.1).

Figure 1. Change from Baseline in Clinical Status (measured on a 7-point Ordinal Scale) at d14.

Conclusion

Overall, our results demonstrate significant geographical differences in the clinical course of severe COVID-19 patients treated with RDV. We observed worse outcomes, such as increased mortality and lower rate of clinical improvement, in patients from Italy compared to other regions.

Disclosures

George Diaz, MD, NO DISCLOSURE DATA Jose Ramon Arribas, MD, Alexa (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Gilead Sciences Inc. (Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Janssen (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Merck (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees)Viiv Healthcare (Advisor or Review Panel member, Speaker’s Bureau, Other Financial or Material Support, Personal fees) Jose Ramon Arribas, MD, NO DISCLOSURE DATA Philip A. Robinson, MD, NO DISCLOSURE DATA Anna Maria Cattelan, MD, NO DISCLOSURE DATA Karen T. Tashima, MD, Bristol-Myers Squibb (Research Grant or Support)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator)GlaxoSmithKline (Research Grant or Support)Merck (Research Grant or Support)Tibotec (Research Grant or Support)Viiv Healthcare (Research Grant or Support) Owen Tak-Yin Tsang, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Owen Tak-Yin Tsang, MD, NO DISCLOSURE DATA Yao-Shen Chen, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Yao-Shen Chen, MD, NO DISCLOSURE DATA Devi SenGupta, MD, Gilead Sciences Inc. (Employee, Shareholder) Elena Vendrame, MD, NO DISCLOSURE DATA Christiana Blair, MS, Gilead Sciences (Employee, Shareholder) Anand Chokkalingam, PhD, Gilead Sciences (Employee) Anu Osinusi, MD, Gilead Sciences (Employee) Diana M. Brainard, MD, Gilead Sciences (Employee) Bum Sik Chin, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Bum Sik Chin, MD, NO DISCLOSURE DATA Christoph Spinner, MD, AbbVie (Advisor or Review Panel member, Other Financial or Material Support, Travel)Bristol-Myers Squibb (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Other Financial or Material Support, Travel)Janssen (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel)MSD (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel)Viiv Healthcare (Grant/Research Support, Advisor or Review Panel member, Other Financial or Material Support, Travel) Gerard J. Criner, MD, Gilead Sciences Inc. (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator) Gerard J. Criner, MD, NO DISCLOSURE DATA Jose Muñoz, MD, NO DISCLOSURE DATA David Chien Boon Lye, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Chien Boon Lye, MD, NO DISCLOSURE DATA Robert L. Gottlieb, MD, Gilead Sciences Inc. (Scientific Research Study Investigator)

548. Baseline characteristics associated with clinical improvement and mortality in hospitalized patients with moderate COVID-19

Background

Remdesivir (RDV) has been shown to shorten recovery time and was well tolerated in patients with severe COVID-19. Here we report baseline characteristics associated with clinical improvement at day (d) 14.

Methods

We enrolled hospitalized patients with confirmed SARS-CoV-2 infection, oxygen saturation &gt;94% on room air, and radiological evidence of pneumonia. Patients were randomized 1:1:1 to receive 5d or 10d of intravenous RDV once daily plus standard of care (SoC), or SoC only. For this analysis, patients were followed through discharge, d14, or death. Baseline demographic and disease characteristics associated with clinical improvement in oxygen support (≥2-point improvement on a 7-category ordinal scale ranging from discharge to death) were evaluated using multivariable logistic regression methods.

Results

584 patients were randomized and treated (5/10d RDV, n=384; SoC: n=200). 159 (27%) were ≥65y, 227 (39%) female, 328 (61%) white, 102 (19%) Asian, and 99 (19%) Black. 252 participants (43%) were enrolled in Europe, 260 (45%) North America (NA), and 72 (12%) in Asia. Most patients (483 [83%]) were not on supplemental oxygen but required medical care at baseline. In a multivariable model, 5/10d RDV was significantly positively associated with clinical improvement (adjusted odds ratio [OR] 1.69, 95% CI: 1.08, 2.65; p=0.0226). Significant covariables positively associated with clinical improvement included age &lt; 65y (p&lt; 0.0001) and region of treatment (Europe and NA vs Asia, p&lt; 0.0001 each; Table); other examined factors were not significantly associated with clinical improvement, including gender, race, ethnicity, baseline oxygen support, duration of symptoms and hospitalization, obesity, and baseline transaminase levels.

Table 1.

Conclusion

In moderate COVID-19 patients, after adjusting for treatment arm, age &lt; 65y and region (NA vs Asia; Europe vs Asia) were associated with higher rates of clinical improvement. These observations recapitulate younger age as positive prognostic factor, and highlight the differences in the impact of the pandemic globally.

Disclosures

Antonella Castagna, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Shu Cheong Hui, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Kathleen M. Mullane, DO, PharmD, Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator) Mamta Jain, MD, Gilead Sciences Inc. (Scientific Research Study Investigator, Research Grant or Support)GlaxoSmithKline (Advisor or Review Panel member)Janssen (Research Grant or Support)Merck (Research Grant or Support) Massimo Galli, MD, Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Other Financial or Material Support, Personal fees) Shan-Chwen Chang, MD, PhD, Gilead Sciences Inc. (Scientific Research Study Investigator) Robert H. Hyland, MD, Gilead Sciences Inc. (Employee, Shareholder) Devi SenGupta, MD, Gilead Sciences Inc. (Employee, Shareholder) Huyen Cao, MD, Gilead Sciences Inc. (Employee, Shareholder) Hailin Huang, PhD, Gilead Sciences Inc. (Employee, Shareholder) Anand Chokkalingam, PhD, Gilead Sciences (Employee) Anu Osinusi, MD, Gilead Sciences (Employee) Diana M. Brainard, MD, Gilead Sciences (Employee) Christoph Lübbert, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Chien Boon Lye, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Chien Boon Lye, MD, NO DISCLOSURE DATA Judith A. Aberg, MD, Theratechnology (Consultant) Enrique Navas Elorza, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Karen T. Tashima, MD, Bristol-Myers Squibb (Research Grant or Support)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator)GlaxoSmithKline (Research Grant or Support)Merck (Research Grant or Support)Tibotec (Research Grant or Support)Viiv Healthcare (Research Grant or Support) Mark McPhail, MD, Gilead Sciences Inc. (Scientific Research Study Investigator)

Remdesivir for 5 or 10 Days in Patients with Severe Covid-19

BACKGROUND

Remdesivir is an RNA polymerase inhibitor with potent antiviral activity in vitro and efficacy in animal models of coronavirus disease 2019 (Covid-19).

METHODS

We conducted a randomized, open-label, phase 3 trial involving hospitalized patients with confirmed SARS-CoV-2 infection, oxygen saturation of 94% or less while they were breathing ambient air, and radiologic evidence of pneumonia. Patients were randomly assigned in a 1:1 ratio to receive intravenous remdesivir for either 5 days or 10 days. All patients received 200 mg of remdesivir on day 1 and 100 mg once daily on subsequent days. The primary end point was clinical status on day 14, assessed on a 7-point ordinal scale.

RESULTS

In total, 397 patients underwent randomization and began treatment (200 patients for 5 days and 197 for 10 days). The median duration of treatment was 5 days (interquartile range, 5 to 5) in the 5-day group and 9 days (interquartile range, 5 to 10) in the 10-day group. At baseline, patients randomly assigned to the 10-day group had significantly worse clinical status than those assigned to the 5-day group (P = 0.02). By day 14, a clinical improvement of 2 points or more on the ordinal scale occurred in 64% of patients in the 5-day group and in 54% in the 10-day group. After adjustment for baseline clinical status, patients in the 10-day group had a distribution in clinical status at day 14 that was similar to that among patients in the 5-day group (P = 0.14). The most common adverse events were nausea (9% of patients), worsening respiratory failure (8%), elevated alanine aminotransferase level (7%), and constipation (7%).

CONCLUSIONS

In patients with severe Covid-19 not requiring mechanical ventilation, our trial did not show a significant difference between a 5-day course and a 10-day course of remdesivir. With no placebo control, however, the magnitude of benefit cannot be determined. (Funded by Gilead Sciences; GS-US-540-5773 ClinicalTrials.gov number, NCT04292899.).

Effect of Remdesivir vs Standard Care on Clinical Status at 11 Days in Patients With Moderate COVID-19: A Randomized Clinical Trial

IMPORTANCE

Remdesivir demonstrated clinical benefit in a placebo-controlled trial in patients with severe coronavirus disease 2019 (COVID-19), but its effect in patients with moderate disease is unknown.

OBJECTIVE

To determine the efficacy of 5 or 10 days of remdesivir treatment compared with standard care on clinical status on day 11 after initiation of treatment.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, open-label trial of hospitalized patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and moderate COVID-19 pneumonia (pulmonary infiltrates and room-air oxygen saturation >94%) enrolled from March 15 through April 18, 2020, at 105 hospitals in the United States, Europe, and Asia. The date of final follow-up was May 20, 2020.

INTERVENTIONS

Patients were randomized in a 1:1:1 ratio to receive a 10-day course of remdesivir (n = 197), a 5-day course of remdesivir (n = 199), or standard care (n = 200). Remdesivir was dosed intravenously at 200 mg on day 1 followed by 100 mg/d.

MAIN OUTCOMES AND MEASURES

The primary end point was clinical status on day 11 on a 7-point ordinal scale ranging from death (category 1) to discharged (category 7). Differences between remdesivir treatment groups and standard care were calculated using proportional odds models and expressed as odds ratios. An odds ratio greater than 1 indicates difference in clinical status distribution toward category 7 for the remdesivir group vs the standard care group.

RESULTS

Among 596 patients who were randomized, 584 began the study and received remdesivir or continued standard care (median age, 57 [interquartile range, 46-66] years; 227 [39%] women; 56% had cardiovascular disease, 42% hypertension, and 40% diabetes), and 533 (91%) completed the trial. Median length of treatment was 5 days for patients in the 5-day remdesivir group and 6 days for patients in the 10-day remdesivir group. On day 11, patients in the 5-day remdesivir group had statistically significantly higher odds of a better clinical status distribution than those receiving standard care (odds ratio, 1.65; 95% CI, 1.09-2.48; P = .02). The clinical status distribution on day 11 between the 10-day remdesivir and standard care groups was not significantly different (P = .18 by Wilcoxon rank sum test). By day 28, 9 patients had died: 2 (1%) in the 5-day remdesivir group, 3 (2%) in the 10-day remdesivir group, and 4 (2%) in the standard care group. Nausea (10% vs 3%), hypokalemia (6% vs 2%), and headache (5% vs 3%) were more frequent among remdesivir-treated patients compared with standard care.

CONCLUSIONS AND RELEVANCE

Among patients with moderate COVID-19, those randomized to a 10-day course of remdesivir did not have a statistically significant difference in clinical status compared with standard care at 11 days after initiation of treatment. Patients randomized to a 5-day course of remdesivir had a statistically significant difference in clinical status compared with standard care, but the difference was of uncertain clinical importance.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04292730.

2490. Longer-Term Safety and Efficacy of Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide in Virologically Suppressed Adults Living With HIV and End-Stage Renal Disease on Chronic Hemodialysis

Background

HIV treatment for individuals with end-stage renal disease (ESRD) on hemodialysis (HD) has previously required complex dose-adjusted regimens. We evaluated the safety and efficacy of single-tablet, once-daily elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) in people living with HIV (PLH) and ESRD on chronic HD.

Methods

Virologically suppressed adult PLH with ESRD on chronic HD for ≥ 6 months were switched to open-label E/C/F/TAF 150/150/200/10 mg once daily for 96 weeks. Efficacy was assessed as the proportion of participants who maintained virologic suppression (HIV RNA < 50 copies/mL) using the snapshot algorithm. Safety and participant satisfaction were assessed throughout the study.

Results

We enrolled 55 participants with median age 51 years (range 23–64) with median time on HD 6 years (range 1–17). In the per protocol analysis set, virologic suppression was maintained in 30 of 31 participants (96.8%, 95% CI [83.3%, 99.9%]) at week 96. In the full analysis set, virologic suppression was maintained in 30 of 55 participants (54.5%; 95% CI [40.6%, 68.0%]); one discontinued therapy due to lack of efficacy, and W96 data were unavailable for 24. Of the 24 participants lacking W96 data, 17 discontinued study drug early and 7 had missing data while on study drug; all had HIV RNA < 50 copies/mL at the last pre-week 96 check. Treatment-emergent AEs occurred in 53 (96.4%) participants, and study-drug-related AEs occurred in 7 (12.7%). Treatment-emergent AEs leading to premature study drug discontinuation occurred in 4 (7.3%) participants; two were considered study-drug-related (allergic pruritus and peripheral neuropathy in one participant each). No study-drug-related serious AEs were observed. 85.7% (30/35) of responding participants reported they were ‘much more satisfied’ with their regimen.

Conclusion

Single-tablet, once-daily E/C/F/TAF was effective in maintaining virologic suppression in PLH on chronic HD over 96 weeks of follow-up. E/C/F/TAF was well tolerated and was associated with improved participant satisfaction. These data demonstrate that E/C/F/TAF is a safe and effective alternative to more complicated regimens in PLH on chronic HD, with the potential to improve patient satisfaction and quality of life.

Disclosures

All authors: No reported disclosures.

Safety of elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide in HIV-1-infected adults with end-stage renal disease on chronic haemodialysis: an open-label, single-arm, multicentre, phase 3b trial

BACKGROUND

Current treatment for HIV-infected individuals with renal failure on haemodialysis frequently requires complex regimens with multiple pills. A daily single-tablet regimen of coformulated elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide is approved in Europe, the USA, and in other regions for use in HIV-1-infected individuals with mild-to-moderate chronic kidney disease (creatinine clearance 30-69 mL/min). We aimed to assess the safety, efficacy, and pharmacokinetics of this regimen in HIV-infected adults with end-stage renal disease on chronic haemodialysis.

METHODS

We did an open-label, single-arm, multicentre, phase 3b trial at 26 outpatient clinics in Austria, France, Germany, and the USA. Participants were HIV-1-infected adults with end-stage renal disease (creatinine clearance <15 mL/min), on chronic haemodialysis for at least 6 months before screening. Virological suppression (ie, plasma HIV-1 RNA <50 copies per mL) on a stable antiretroviral regimen was required for at least 6 months before screening with a CD4 count of at least 200 cells per μL. We switched all participants to coformulated elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg, and tenofovir alafenamide 10 mg once daily, taken after haemodialysis for up to 96 weeks. We did assessments at study visits at weeks 2, 4, 8, 12, 24, 36, and 48, and every 12 weeks thereafter up to 96 weeks. The primary endpoint was the incidence of treatment-emergent adverse events of grade 3 or higher up to week 48. All participants who received at least one dose of study drug were included in the primary analysis. This study is registered with ClinicalTrials.gov (NCT02600819) and is closed to new participants.

FINDINGS

Between Feb 1, and Nov 3, 2016, 55 participants were enrolled and received at least one dose of study drug. Through week 48, 18 of 55 participants (33%, 95% CI 20-45) had an adverse event of grade 3 or higher on study treatment. Treatment-emergent grade 3 or higher adverse events that occurred in more than one participant included anaemia, osteomyelitis, prolonged electrocardiogram QT, fluid overload, hyperkalaemia, hypertension, and hypotension (all n=2). No adverse event of grade 3 or higher was considered by the site investigators to be treatment related. Three participants (5%, 95% CI 0-11) discontinued treatment because of adverse events; one of these (grade 1 allergic pruritus) was considered treatment related. Treatment-related adverse events were reported for six individuals (11%, 95% CI 3-19), the most common of which was nausea (in four individuals [7%]); all treatment-related adverse events were grade 1 or 2 in severity.

INTERPRETATION

At 48 weeks, switching to the single-tablet regimen of elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide was well tolerated. This regimen might provide a tolerable and convenient option for ongoing treatment of HIV-1 infection in adults with end-stage renal disease on chronic haemodialysis.

FUNDING

Gilead Sciences.

Switching to coformulated rilpivirine (RPV), emtricitabine (FTC) and tenofovir alafenamide from either RPV, FTC and tenofovir disoproxil fumarate (TDF) or efavirenz, FTC and TDF: 96-week results from two randomized clinical trials

Objectives

The single‐tablet regimen rilpivirine, emtricitabine and tenofovir alafenamide (RPV/FTC/TAF) for treatment of HIV‐1‐infected adults was approved based on bioequivalence. We assessed the clinical efficacy, safety and tolerability of switching to RPV/FTC/TAF from either RPV/FTC/tenofovir disoproxil fumarate (TDF) or efavirenz (EFV)/FTC/TDF.

Methods

We conducted two distinct randomized, double‐blind, active‐controlled, noninferiority trials in participants taking RPV/FTC/TDF (Study 1216) and EFV/FTC/TDF (Study 1160). Each study randomized virologically suppressed (HIV‐1 RNA < 50 copies/mL) adults (1:1) to switch to RPV/FTC/TAF or continue their current regimen for 96 weeks. We evaluated efficacy as the proportion with HIV‐1 RNA < 50 copies/mL using the Food and Drug Administration snapshot algorithm and prespecified bone and renal endpoints at week 96.

Results

We randomized and treated 630 participants in Study 1216 (RPV/FTC/TAF, n = 316; RPV/FTC/TDF, n = 314) and 875 in Study 1160 (RPV/FTC/TAF, n = 438; EFV/FTC/TDF, n = 437). In both studies, the efficacy of switching to RPV/FTC/TAF was noninferior to that of continuing baseline therapy at week 96, with respective percentages of patients with HIV RNA < 50 copies/mL being 89.2% versus 88.5% in Study 1216 [difference 0.7%; 95% confidence interval (CI) −4.3 to +5.8%] and 85.2% versus 85.1% in Study 1160 (difference 0%; 95% CI −4.8 to +4.8%). No participant on RPV/FTC/TAF developed treatment‐emergent resistance versus two on EFV/FTC/TDF and one on RPV/FTC/TDF. Compared with continuing baseline therapy, significant improvements in bone mineral density and renal tubular markers were observed in the RPV/FTC/TAF groups (P < 0.001).

Conclusions

Switching to RPV/FTC/TAF from RPV/FTC/TDF or EFV/FTC/TDF was safe and effective and improved bone mineral density and renal biomarkers up to 96 weeks with no cases of treatment‐emergent resistance.

Coformulated bictegravir, emtricitabine, and tenofovir alafenamide versus dolutegravir with emtricitabine and tenofovir alafenamide, for initial treatment of HIV-1 infection (GS-US-380-1490): a randomised, double-blind, multicentre, phase 3, non-inferiority trial

BACKGROUND

Integrase strand transfer inhibitors (INSTIs) coadministered with two nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs) are recommended as first-line treatment for HIV, and coformulated fixed-dose combinations are preferred to facilitate adherence. We report 48-week results from a study comparing initial HIV-1 treatment with bictegravir-a novel INSTI with a high in-vitro barrier to resistance and low potential as a perpetrator or victim of clinically relevant drug interactions-coformulated with the NRTI combination emtricitabine and tenofovir alafenamide as a fixed-dose combination to dolutegravir administered with coformulated emtricitabine and tenofovir alafenamide.

METHODS

In this randomised, double-blind, multicentre, placebo-controlled, non-inferiority trial, HIV-infected adults were screened and enrolled at 126 outpatient centres in 10 countries in Australia, Europe, Latin America, and North America. Participants were previously untreated adults (HIV-1 RNA ≥500 copies per mL) with estimated glomerular filtration rate of at least 30 mL/min. Chronic hepatitis B virus or hepatitis C co-infection was allowed. We randomly assigned participants (1:1) to receive oral fixed-dose combination bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide 25 mg or dolutegravir 50 mg with coformulated emtricitabine 200 mg and tenofovir alafenamide 25 mg, with matching placebo, once a day for 144 weeks. Investigators, participants, study staff, and those assessing outcomes were masked to treatment group. All participants who received at least one dose of study drug were included in primary efficacy and safety analyses. The primary endpoint was the proportion of participants with plasma HIV-1 RNA of less than 50 copies per mL at week 48 (US Food and Drug Administration snapshot algorithm), with a prespecified non-inferiority margin of -12%. This study is registered with ClinicalTrials.gov, number NCT02607956.

FINDINGS

Between Nov 11, 2015, and July 15, 2016, 742 participants were screened for eligibility, of whom 657 were randomly assigned to treatment (327 with bictegravir, emtricitabine, and tenofovir alafenamide fixed-dose combination [bictegravir group] and 330 with dolutegravir plus emtricitabine and tenofovir alafenamide [dolutegravir group]). 320 participants who received the bictegravir regimen and 325 participants who received the dolutegravir regimen were included in the primary efficacy analyses. At week 48, HIV-1 RNA <50 copies per mL was achieved in 286 (89%) of 320 participants in the bictegravir group and 302 (93%) of 325 in the dolutegravir group (difference -3·5%, 95·002% CI -7·9 to 1·0, p=0·12), showing non-inferiority of the bictegravir regimen to the dolutegravir regimen. No treatment-emergent resistance to any study drug was observed. Incidence and severity of adverse events were similar between groups, and few participants discontinued treatment due to adverse events (5 [2%] of 320 in the bictegravir group and 1 [<1%] 325 in the dolutegravir group). Study drug-related adverse events were less common in the bictegravir group than in the dolutegravir group (57 [18%] of 320 vs 83 [26%] of 325, p=0·022).

INTERPRETATION

At 48 weeks, virological suppression with the bictegravir regimen was achieved and was non-inferior to the dolutegravir regimen in previously untreated adults. There was no emergent resistance to either regimen. The fixed-dose combination of bictegravir, emtricitabine, and tenofovir alafenamide was safe and well tolerated compared with the dolutegravir regimen.

FUNDING

Gilead Sciences Inc.

Anti-HERV-K (HML-2) capsid antibody responses in HIV elite controllers

BACKGROUND

Human endogenous retroviruses (HERVs) comprise approximately 8% of the human genome and while the majority are transcriptionally silent, the most recently integrated HERV, HERV-K (HML-2), remains active. During HIV infection, HERV-K (HML-2) specific mRNA transcripts and viral proteins can be detected. In this study, we aimed to understand the antibody response against HERV-K (HML-2) Gag in the context of HIV-1 infection.

RESULTS

We developed an ELISA assay using either recombinant protein or 164 redundant "15mer" HERV-K (HML-2) Gag peptides to test sera for antibody reactivity. We identified a total of eight potential HERV-K (HML-2) Gag immunogenic domains: two on the matrix (peptides 16 and 31), one on p15 (peptide 85), three on the capsid (peptides 81, 97 and 117), one on the nucleocapsid (peptide 137) and one on the QP1 protein (peptide 157). Four epitopes (peptides 16, 31, 85 and 137) were highly immunogenic. No significant differences in antibody responses were found between HIV infected participants (n = 40) and uninfected donors (n = 40) for 6 out of the 8 epitopes tested. The antibody response against nucleocapsid (peptide 137) was significantly lower (p < 0.001), and the response to QP1 (peptide 157) significantly higher (p < 0.05) in HIV-infected adults compared to uninfected individuals. Among those with HIV infection, the level of response against p15 protein (peptide 85) was significantly lower in untreated individuals controlling HIV ("elite" controllers) compared to untreated non-controllers (p < 0.05) and uninfected donors (p < 0.05). In contrast, the response against the capsid protein (epitopes 81 and 117) was significantly higher in controllers compared to uninfected donors (p < 0.001 and <0.05 respectively) and non-controllers (p < 0.01 and <0.05). Peripheral blood mononuclear cells (PBMCs) from study participants were tested for responses against HERV-K (HML-2) capsid recombinant peptide in gamma interferon (IFN-γ) enzyme immunospot (Elispot) assays. We found that the HERV-K (HML-2) Gag antibody and T cell response by Elispot were significantly correlated.

CONCLUSIONS

HIV elite controllers had a strong cellular and antibody response against HERV-K (HML-2) Gag directed mainly against the Capsid region. Collectively, these data suggest that anti-HERV-K (HML-2) antibodies targeting capsid could have an immunoprotective effect in HIV infection.

Switching from efavirenz, emtricitabine, and tenofovir disoproxil fumarate to tenofovir alafenamide coformulated with rilpivirine and emtricitabine in virally suppressed adults with HIV-1 infection: a randomised, double-blind, multicentre, phase 3b, non-inferiority study

BACKGROUND

Tenofovir alafenamide is a prodrug that reduces tenofovir plasma concentrations by 90% compared with tenofovir disoproxil fumarate, thereby decreasing bone and renal risks. The coformulation of rilpivirine, emtricitabine, and tenofovir alafenamide has recently been approved, and we aimed to investigate the efficacy, safety, and tolerability of switching to this regimen compared with remaining on coformulated efavirenz, emtricitabine, and tenofovir disoproxil fumarate.

METHODS

In this randomised, double-blind, placebo-controlled, non-inferiority trial, HIV-1-infected adults were enrolled at 120 hospitals and outpatient clinics in eight countries in North America and Europe. Participants were virally suppressed (HIV-1 RNA <50 copies per mL) on efavirenz, emtricitabine, and tenofovir disoproxil fumarate for at least 6 months before enrolment and had creatinine clearance of at least 50 mL/min. Participants were randomly assigned (1:1) to receive a single-tablet regimen of rilpivirine (25 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg) or to continue a single-tablet regimen of efavirenz (600 mg), emtricitabine (200 mg), and tenofovir disoproxil fumarate (300 mg), with matching placebo. Investigators, participants, study staff, and those assessing outcomes were masked to treatment group. The primary endpoint was the proportion of participants with plasma HIV-1 RNA of less than 50 copies per mL at week 48 (assessed by the US Food and Drug Administration snapshot algorithm), with a prespecified non-inferiority margin of 8%. This study was registered with ClinicalTrials.gov, number NCT02345226.

FINDINGS

Between Jan 26, 2015, and Aug 27, 2015, 875 participants were randomly assigned and treated (438 with rilpivirine, emtricitabine, and tenofovir alafenamide and 437 with efavirenz, emtricitabine, tenofovir disoproxil fumarate). Viral suppression at week 48 was maintained in 394 (90%) of 438 participants assigned to the tenofovir alafenamide regimen and 402 (92%) of 437 assigned to the tenofovir disoproxil fumarate regimen (difference -2·0%, 95·001% CI -5·9 to 1·8), demonstrating non-inferiority. 56 (13%) of 438 in participants in the rilpivirine, emtricitabine, and tenofovir alafenamide group experienced treatment-related adverse events compared with 45 (10%) of 437 in the efavirenz, emtricitabine, and tenofovir disoproxil fumarate group.

INTERPRETATION

Switching to rilpivirine, emtricitabine, and tenofovir alafenamide from efavirenz, emtricitabine, and tenofovir disoproxil fumarate was non-inferior in maintaining viral suppression and was well tolerated at 48 weeks. These findings support guidelines recommending tenofovir alafenamide-based regimens, including coformulation with rilpivirine and emtricitabine, as initial and ongoing treatment for HIV-1 infection.

FUNDING

Gilead Sciences.

Switching from tenofovir disoproxil fumarate to tenofovir alafenamide coformulated with rilpivirine and emtricitabine in virally suppressed adults with HIV-1 infection: a randomised, double-blind, multicentre, phase 3b, non-inferiority study

BACKGROUND

Tenofovir alafenamide, a tenofovir prodrug, results in 90% lower tenofovir plasma concentrations than does tenofovir disproxil fumarate, thereby minimising bone and renal risks. We investigated the efficacy, safety, and tolerability of switching to a single-tablet regimen containing rilpivirine, emtricitabine, and tenofovir alafenamide compared with remaining on rilpivirine, emtricitabine, and tenofovir disoproxil fumarate.

METHODS

In this randomised, double-blind, multicentre, placebo-controlled, non-inferiority trial, HIV-1-infected adults were screened and enrolled at 119 hospitals in 11 countries in North America and Europe. Participants were virally suppressed (HIV-1 RNA <50 copies per mL) on rilpivirine, emtricitabine, and tenofovir disoproxil fumarate for at least 6 months before enrolment and had creatinine clearance of at least 50 mL/min. Participants were randomly assigned (1:1) to receive a single-tablet regimen of either rilpivirine (25 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg) or to remain on a single-tablet regimen of rilpivirine (25 mg), emtricitabine (200 mg), and tenofovir disoproxil fumarate (300 mg), with matching placebo, once daily for 96 weeks. Investigators, participants, study staff, and those assessing outcomes were masked to treatment group. All participants who received one dose of study drug and were on the tenofovir disoproxil fumarate regimen before screening were included in primary efficacy analyses. The primary endpoint was the proportion of participants with less than 50 copies per mL of plasma HIV-1 RNA at week 48 (by the US Food and Drug Administration snapshot algorithm), with a prespecified non-inferiority margin of 8%. This study was registered with ClinicalTrials.gov, number NCT01815736.

FINDINGS

Between Jan 26, 2015, and Aug 25, 2015, 630 participants were randomised (316 to the tenofovir alafenamide group and 314 to the tenofovir disoproxil fumarate group). At week 48, 296 (94%) of 316 participants on tenofovir alafenamide and 294 (94%) of 313 on tenofovir disoproxil fumarate had maintained less than 50 copies per mL HIV-1 RNA (difference -0·3%, 95·001% CI -4·2 to 3·7), showing non-inferiority of tenofovir alafenamide to tenofovir disoproxil fumarate. Numbers of adverse events were similar between groups. 20 (6%) of 316 participants had study-drug related adverse events in the tenofovir alafenamide group compared with 37 (12%) of 314 in the tenofovir disoproxil fumarate group; none of these were serious.

INTERPRETATION

Switching to rilpivirine, emtricitabine, and tenofovir alafenamide was non-inferior to continuing rilpivirine, emtricitabine, tenofovir disoproxil fumarate in maintaining viral suppression and was well tolerated at 48 weeks. These findings support guidelines recommending tenofovir alafenamide-based regimens, including coformulation with rilpivirine and emtricitabine, as initial and ongoing treatment for HIV-1 infection.

FUNDING

Gilead Sciences.

Relative mRNA Expression Levels of Restriction Factors and Antiviral Genes in Fetal and Adult Human Monocytes and Monocyte-Derived Macrophages

Among untreated HIV-infected pregnant women, the frequency of mother-to-child transmission of HIV is low (5-10%), with most infections occurring at or after birth. Given findings that fetal and adult monocytes are distinct from one another in terms of basal transcriptional profiles, and in phosphorylation of signal transducer and activators of transcription in response to cytokines, we hypothesized that fetal CD14+CD16- monocyte and monocyte-derived macrophages (MDMs) might, compared to their adult counterparts, express higher levels of transcripts for restriction factors and antiviral factors at baseline and/or after stimulation with cytokines that might be induced upon transmission of HIV in utero, for example, IFNα, IFNγ, and IL-6. We carried out these experiments and noted that a few genes, including APOBEC3B, APOBEC3C, and IFITM2, were expressed to a greater degree in fetal monocytes compared to adults. Similarly, the expression levels of APOBEC3F and TRIM32 were greater in fetal MDMs. However, most of these differences were not observed after stimulation with cytokines and the vast majority of antiviral genes were more highly expressed in adults. Therefore, the results of this study are not consistent with the hypothesis that increased expression of antiviral genes in fetal myeloid cells confers immune protection to fetuses in utero.

Bacteroides are associated with GALT iNKT cell function and reduction of microbial translocation in HIV-1 infection

Invariant natural killer T (iNKT) cells are innate-like T cells that respond to lipid antigens presented by CD1d. These immunoregulatory cells have the capacity for rapid cytokine release after antigen recognition and are essential for the activation of multiple arms of the immune response. HIV-1 infection is associated with iNKT cell depletion in the peripheral blood; however, their role in the gastrointestinal-associated lymphoid tissue (GALT) is less well studied. Our results show that iNKT cells are found at a higher frequency in GALT compared with blood, particularly in HIV-1 elite controllers. The capacity of iNKT cells to produce interleukin-4 (IL-4) and IL-10 in the GALT was associated with less immune activation and lower markers of microbial translocation, whereas regulatory T cell frequency showed positive associations with immune activation. We hypothesized that the composition of the microbiota would influence iNKT cell frequency and function. We found positive associations between the abundance of several Bacteroides species and iNKT cell frequency and their capacity to produce IL-4 in the GALT but not in the blood. Overall, our results are consistent with the hypothesis that GALT iNKT cells, influenced by certain bacterial species, may have a key role in regulating immune activation in HIV-1 infection.

p16INK4a Expression and Immunologic Aging in Chronic HIV Infection

Chronic HIV infection is characterized by increased immune activation and immunosenescence. p16 ^INK4a (p16) is a member of the cyclin-dependent kinase antagonist family that inhibits cellular proliferation, and its protein expression increases during normal chronological aging. However, some infectious diseases can increase the expression of this anti-proliferative protein, potentially accelerating immunological aging and dysfunction. In order to investigate the immunological aging in HIV patients, p16 protein expression was evaluated by flow cytometry, in T cell subsets in a cohort of chronically HIV-infected patients on and off ART as well as age-matched healthy controls. Results showed that untreated HIV-infected subjects exhibited increased per-cell p16 protein expression that was discordant with chronological aging. ART restored p16 protein expression to levels comparable with HIV-negative subjects in the CD4 compartment, but not in CD8 T cells, which can be an indicative of an irreversible activation/exhaustion status on these cells. Additionally, the frequency of activated CD4+ and CD8+ T cells was positively correlated with p16 expression in CD4+ and CD8+ T cells in untreated subjects. In contrast to healthy controls, untreated HIV-infected individuals had increased p16 levels within the effector memory (T_EM) subset, indicating a possible role for this marker in impaired clonal expansion during antiviral effector function. Taken together, these data demonstrate that chronic HIV infection is associated with elevated expression of the cellular aging marker p16 in T cells. ART restored normal p16 levels in the CD4+ T cell compartment, indicating that use of therapy can be of fundamental importance to normal cell cycling and maintaining immune homeostasis.

Safety, efficacy, and pharmacokinetics of a single-tablet regimen containing elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide in treatment-naive, HIV-infected adolescents: a single-arm, open-label trial

BACKGROUND

The prodrug tenofovir alafenamide is associated with improved renal and bone safety compared with tenofovir disoproxil fumarate. We aimed to assess safety, pharmacokinetics, and efficacy of this single-tablet, fixed-dose combination of elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide in HIV-infected, treatment-naive adolescents.

METHODS

We did a 48 week, single-arm, open-label trial in treatment-naive adolescents with HIV from ten hospital clinics in South Africa, Thailand, Uganda, and the USA. Eligible participants were aged 12-18 years, with plasma HIV-1 RNA of at least 1000 copies per mL, a CD4 count of at least 100 cells per μL, and estimated glomerular filtration rate of at least 90 mL/min per 1·73 m² by the Schwartz formula, bodyweight of at least 35 kg, and an HIV-1 genotype with sensitivity to elvitegravir, emtricitabine, and tenofovir. Participants received a single-tablet regimen once per day with food (administered by their parent or carer) containing 150 mg elvitegravir, 150 mg cobicistat, 200 mg emtricitabine, and 10 mg tenofovir alafenamide. Study visits to the clinic occurred at weeks 1, 2, 4, 8, 12, 16, 24, 32, 40, and 48. The coprimary endpoints were the pharmacokinetic parameters of area under the curve (AUC) concentration at the end of the dosing interval (AUC_tau) for elvitegravir and the AUC from time zero to the last quantifiable concentration (AUC_last) for tenofovir alafenamide, incidence of treatment-emergent serious adverse events, and all adverse events that emerged after treatment started (including data for bone mineral density). All participants who received one dose of study drug were included in the primary and safety analyses. This trial is registered with ClinicalTrials.gov, number NCT01854775.

FINDINGS

Between May 22, 2013, and July 22, 2014, we enrolled 50 participants, and all 50 received the assigned treatment; 24 participated in the intensive pharmacokinetic assessment. 48 patients completed the 48 weeks of treatment; two discontinued (one withdrew consent at week 8, one was lost to follow-up at week 12). The regimen was well tolerated and no discontinuations related to adverse events occurred. The mean AUC_tau for elvitegravir was 23 840 ng × h per mL (coefficient of variation [CV] 25·5%), and the mean AUC_last for tenofovir alafenamide was 189 ng × h per mL (CV 55·8%). Four participants (8%) had a serious adverse event, one of which (intermediate uveitis) was deemed related to the study regimen but resolved without treatment interruption. The most common study drug-related adverse events were nausea (in ten participants), abdominal pain (in six), and vomiting (in five). Exposures to the elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide regimen were similar to those previously noted in adults.

INTERPRETATION

The elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide regimen was well tolerated and achieved component plasma pharmacokinetic exposures similar to those in adults. Although non-comparative with a small sample size, these data support the use of this regimen in HIV-infected adolescents and its timely assessment in younger children.

FUNDING

Gilead Sciences.

Switching to Tenofovir Alafenamide, Coformulated With Elvitegravir, Cobicistat, and Emtricitabine, in HIV-Infected Patients With Renal Impairment: 48-Week Results From a Single-Arm, Multicenter, Open-Label Phase 3 Study

BACKGROUND

Tenofovir alafenamide (TAF) is a novel tenofovir prodrug with improved renal and bone safety compared with TDF-containing regimens. We report the 48 week safety and efficacy of a once-daily single tablet regimen of elvitegravir 150 mg (E), cobicistat 150 mg (C), emtricitabine 200 mg (F), and TAF 10 mg (E/C/F/TAF) in HIV-1-infected patients with mild to moderate renal impairment.

METHODS

We enrolled virologically suppressed HIV-1-infected subjects with estimated creatinine clearance (CrCl) 30-69 mL/min in a single-arm, open-label study to switch regimens to E/C/F/TAF. The primary endpoint was the change from baseline in glomerular filtration rate estimated using various formulae. This study is registered with ClinicalTrials.gov, number NCT01818596.

FINDINGS

We enrolled and treated 242 patients with mean age 58 years, 18% Black, 39% hypertension, 14% diabetes. Through week 48, no significant change in estimated CrCl was observed. Two patients (0.8%) discontinued study drug for decreased creatinine clearance, neither had evidence of renal tubulopathy and both had uncontrolled hypertension. Subjects had significant improvements in proteinuria, albuminuria, and tubular proteinuria (P < 0.001 for all). Hip and spine bone mineral density significantly increased from baseline to week 48 (mean percent change +1.47 and +2.29, respectively, P < 0.05). Ninety-two percent (222 patients) maintained HIV-1 RNA <50 copies per milliliter at week 48.

INTERPRETATION

Switch to E/C/F/TAF was associated with minimal change in GFR. Proteinuria, albuminuria and bone mineral density significantly improved. These data support the efficacy and safety of once daily E/C/F/TAF in HIV+ patients with mild or moderate renal impairment without dose adjustment.

Cutting edge: An antibody recognizing ancestral endogenous virus glycoproteins mediates antibody-dependent cellular cytotoxicity on HIV-1-infected cells

The failure of antiviral vaccines is often associated with rapid viral escape from specific immune responses. In the past, conserved epitope or algorithmic epitope selections, such as mosaic vaccines, have been designed to diversify immunity and to circumvent potential viral escape. An alternative approach is to identify conserved stable non-HIV-1 self-epitopes present exclusively in HIV-1-infected cells. We showed previously that human endogenous retroviral (HERV) mRNA transcripts and protein are found in cells of HIV-1-infected patients and that HERV-K (HML-2)-specific T cells can eliminate HIV-1-infected cells in vitro. In this article, we demonstrate that a human anti-HERV-K (HML-2) transmembrane protein Ab binds specifically to HIV-1-infected cells and eliminates them through an Ab-dependent cellular cytotoxicity mechanism in vitro. Thus, Abs directed against epitopes other than HIV-1 proteins may have a role in eliminating HIV-1-infected cells and could be targeted in novel vaccine approaches or immunotherapeutic modalities.

HIV-1 infection induces a novel B cell response against HERV-K (HML-2) TM protein (P6209)

The presence of HERV-K (HML-2) mRNA in plasma and a corresponding specific T cell response during HIV-1 infection is well-documented. We hypothesized that HIV-1 also induces a specific HERV-K (HML-2) EnvelopeBcell response due to the expression of envelope protein on the infected cell surface. This led to the concept that HERV-K (HML-2) Env could be used as an HIV-1 Associated Neo Antigen (HANA) to target infected cells. We showed that the humoral response against HERV-K (HML-2) Env is restricted to two sequences on each envelope sub-unit, the surface unit (SU) and transmembrane (TM) proteins. During HIV-1 infection, we observed an increase of the anti-TM antibody titer and a decrease of the anti-SU antibody titer. Interestingly, we found that HIV-1-infected elite controllers had high titers of anti-TM antibodies compared to HIV-1 infected patients on effective HAART or healthy uninfected donors. We showed that TM is preferentially transactivated and expressed on the cell surface in HIV-1 infected cells. Using HA-137, a human anti-TM antibody, we showed that TM protein is preferentially expressed in the myeloid cell subset as well as in a distinct T cell subset. These findings highlight the crucial role of the monocyte/macrophage lineage in the induction of the anti-HERV-K (HML-2) TM Bcell response.This study suggests that the anti-TM humoral response may play a role in HIV-1 pathogenesis and could provide a new tool for immunotherapeutic strategies.

Identification of human endogenous retrovirus (HERV-K(HML-2))-specific mucosal CD4+ T cell responses in HIV-1-exposed, seronegative individuals (P6195)

The transcriptional silence of human endogenous retroviruses (HERV) can be disrupted in HIV-1 infection. We have reported that the strength of the HERV-specific CD8+ T cell response predicts lower HIV-1 viral load in untreated adults. To determine whether HERV-K immunity plays a role in inhibiting HIV-1 replication at a major site of transmission and CD4+ T cell depletion, we assessed these responses in gut-associated lymphoid tissue (GALT) from rectosigmoid biopsies and blood of HIV-1 exposed, seronegative (HESN) individuals (n=6) by flow cytometry. CMV pp65- and HIV-1 Gag-specific T cells were also measured, and all responses were compared with peripheral antigen-specific responses in uninfected, low-risk controls (n=11). With the exception of stronger CMV-specific CD8+ T cell responses in the HESN group (p=0.024), there were no significant differences between the magnitudes of peripheral antigen-specific T cell responses in the HESN vs. controls. However, HESN subjects had remarkably robust mucosal HIV-1- (median %CD4+cytokine+cells=2.67) and HERV-specific (median %CD4+cytokine+cells=3.41) CD4+ responses, which were much stronger than the corresponding PBMC responses (p=0.0079 and p&lt;0.0001, respectively). These findings suggest that the GALT is an important site of HERV-K expression and immunity in individuals exposed to HIV-1, and should be further investigated in the context of novel vaccine strategies that target conserved antigens such as HERV.

HERV-K-specific T cells eliminate diverse HIV-1/2 and SIV primary isolates

The genetic diversity of HIV-1 represents a major challenge in vaccine development. In this study, we establish a rationale for eliminating HIV-1-infected cells by targeting cellular immune responses against stable human endogenous retroviral (HERV) antigens. HERV DNA sequences in the human genome represent the remnants of ancient infectious retroviruses. We show that the infection of CD4+ T cells with HIV-1 resulted in transcription of the HML-2 lineage of HERV type K [HERV-K(HML-2)] and the expression of Gag and Env proteins. HERV-K(HML-2)-specific CD8+ T cells obtained from HIV-1-infected human subjects responded to HIV-1-infected cells in a Vif-dependent manner in vitro. Consistent with the proposed mode of action, a HERV-K(HML-2)-specific CD8+ T cell clone exhibited comprehensive elimination of cells infected with a panel of globally diverse HIV-1, HIV-2, and SIV isolates in vitro. We identified a second T cell response that exhibited cross-reactivity between homologous HIV-1-Pol and HERV-K(HML-2)-Pol determinants, raising the possibility that homology between HIV-1 and HERVs plays a role in shaping, and perhaps enhancing, the T cell response to HIV-1. This justifies the consideration of HERV-K(HML-2)-specific and cross-reactive T cell responses in the natural control of HIV-1 infection and for exploring HERV-K(HML-2)-targeted HIV-1 vaccines and immunotherapeutics.

Identification of human endogenous retrovirus-specific T cell responses in vertically HIV-1-infected subjects

Human endogenous retrovirus (HERV)-specific T cell responses in HIV-1-infected adults have been reported. Whether HERV-specific immunity exists in vertically HIV-1-infected children is unknown. We performed a cross-sectional analysis of HERV-specific T cell responses in 42 vertically HIV-1-infected children. HERV (-H, -K, and -L family)-specific T cell responses were identified in 26 of 42 subjects, with the greatest magnitude observed for the responses to HERV-L. These HERV-specific T cell responses were inversely correlated with the HIV-1 plasma viral load and positively correlated with CD4(+) T cell counts. These data indicate that HERV-specific T cells may participate in controlling HIV-1 replication and that certain highly conserved HERV-derived proteins may serve as promising therapeutic vaccine targets in HIV-1-infected children.

Impaired dimensional selection but intact use of reward feedback during visual discrimination learning in Parkinson's disease

It has been suggested that Parkinson's disease (PD) impairs the ability to learn on the basis of reward or reinforcing feedback i.e., by trial-and-error. In many learning tasks, particular 'dimensions' of stimulus information are relevant whilst others are irrelevant; therefore, efficient performance depends on identifying the dimensions of these 'compound' stimuli and selecting the relevant dimension for further processing. We investigated the ability of patients with PD, as well as patients with Huntington's disease and patients with frontal or temporal lobe lesions, to learn visual discriminations which required either a number of associations to be learned concurrently (the 'eight-pair' task) or the selection of information from compound stimuli (the 'five-dimension' task), both tasks being learned by trial-and-error. None of the basal ganglia disorder patient groups was impaired on the eight-pair task, militating against a crucial role for these brain structures in trial-and-error learning per se. Patients with mild, medicated PD, but not unmedicated PD patients, were impaired at identifying all five feature dimensions in the five-dimension task, implying dopaminergic 'overdosing' of the ability to analyse compound stimuli in terms of their component dimensions. Temporal lobe lesion patients performed similarly, suggesting that the temporal lobe may be the site of the medication overdose effect. Patients with severe, medicated PD were impaired at compound discrimination learning on the five-dimension task in the absence of an underlying impairment in identifying component stimulus dimensions; this pattern resembled that seen in Huntington's disease and frontal lobe lesion patients, implying that fronto-striatal circuitry is involved in the formation of rules based upon selected stimulus dimensions.

Heat shock protein-mediated cross-presentation of exogenous HIV antigen on HLA class I and class II

Strong CD4(+) and CD8(+) T cell responses are considered important immune components for controlling HIV infection, and their priming may be central to an effective HIV vaccine. We describe in this study an approach by which multiple CD4(+) and CD8(+) T cell epitopes are processed and presented from an exogenously added HIV-1 Gag-p24 peptide of 32 aa complexed to heat shock protein (HSP) gp96. CD8(+) T cell recognition of the HSP/peptide complex, but not the peptide alone, was inhibited by brefeldin A, suggesting an endoplasmic reticulum-dependent pathway. This is the first report to describe efficient processing and simultaneous presentation of overlapping class I- and class II-restricted epitopes from the same extracellularly added precursor peptide complexed to HSP. Given previous reports of the strong immunogenicity of HSP/peptide complexes, the present data suggest that HSP-complexed peptides containing multiple MHC class I- and class II-restricted epitopes represent potential vaccine candidates for HIV and other viral infections suitable to induce effective CTL memory by simultaneously providing CD4 T cell help.

Consistent cytotoxic-T-lymphocyte targeting of immunodominant regions in human immunodeficiency virus across multiple ethnicities

Although there is increasing evidence that virus-specific cytotoxic-T-lymphocyte (CTL) responses play an important role in the control of human immunodeficiency virus (HIV) replication in vivo, only scarce CTL data are available for the ethnic populations currently most affected by the epidemic. In this study, we examined the CD8(+)-T-cell responses in African-American, Caucasian, Hispanic, and Caribbean populations in which clade B virus dominates and analyzed the potential factors influencing immune recognition. Total HIV-specific CD8(+)-T-cell responses were determined by enzyme-linked immunospot assays in 150 HIV-infected individuals by using a clade B consensus sequence peptide set spanning all HIV proteins. A total of 88% of the 410 tested peptides were recognized, and Nef- and Gag-specific responses dominated the total response for each ethnicity in terms of both breadth and magnitude. Three dominantly targeted regions within these proteins that were recognized by >90% of individuals in each ethnicity were identified. Overall, the total breadth and magnitude of CD8(+)-T-cell responses correlated with individuals' CD4 counts but not with viral loads. The frequency of recognition for each peptide was highly correlated with the relative conservation of the peptide sequence, the presence of predicted immunoproteasomal cleavage sites within the C-terminal half of the peptide, and a reduced frequency of amino acids that impair binding of optimal epitopes to the restricting class I molecules. The present study thus identifies factors that contribute to the immunogenicity of these highly targeted and relatively conserved sequences in HIV that may represent promising vaccine candidates for ethnically heterogeneous populations.

A comparative trial of granulocyte-colony-stimulating factor and dexamethasone, separately and in combination, for the mobilization of neutrophils in the peripheral blood of normal volunteers

BACKGROUND

The clinical utility of polymorphonuclear neutrophil (PMN) transfusion therapy has been compromised, in part, by the inability to obtain sufficient quantities of functional neutrophils from donors. To define the optimal conditions for mobilization of PMNs in granulocyte donors, the effects of granulocyte-colony-stimulating factor (G-CSF) and dexamethasone, separately and in combination, on PMN counts in normal volunteers were compared.

STUDY DESIGN AND METHODS

Five normal subjects were randomly assigned to each of the following single-dose regimens in 5 consecutive weeks: 1) G-CSF, 300 micrograms given subcutaneously; 2) G-CSF, 600 micrograms subcutaneously: 3) dexamethasone, 8 mg given orally; 4) G-CSF, 300 micrograms subcutaneously, plus dexamethasone, 8 mg orally; and 5) G-CSF, 600 micrograms subcutaneously, plus dexamethasone 8 mg orally. Venous blood was collected at 0, 6, 12, and 24 hours after drug administration for the determination of absolute neutrophil counts (ANCs).

RESULTS

Maximal ANC was achieved at 12 hours after each regimen, except dexamethasone alone (maximum, 24 hours). Dexamethasone significantly increased the maximal ANC induced by either dose of G-CSF alone (p < 0.05). The greatest mobilization of PMNs occurred after the administration of G-CSF (600 micrograms) and dexamethasone (8 mg); the ANC increased from a mean baseline value of 3,594 per microL to 43,017 per microL at 12 hours. All of the drug regimens were well tolerated.

CONCLUSION

Dexamethasone significantly increases the level of neutrophilia induced in normal subjects by G-CSF. The combination of dexamethasone and G-CSF (at the dosages used in this study) is a convenient, well-tolerated regimen for the mobilization of PMNs in the peripheral blood of granulocyte donors. Moreover, the optimal quantitative yield of PMNs is likely to be achieved by leukapheresis 12 hours after drug administration.

A protein linkage map of Escherichia coli bacteriophage T7

Genome sequencing projects are predicting large numbers of novel proteins, whose interactions with other proteins must mediate the function of cellular processes. To analyse these networks, we used the yeast two-hybrid system on a genome-wide scale to identify 25 interactions among the proteins of Escherichia coli bacteriophage T7. Among these is a set of six interactions connecting proteins that function in DNA replication and DNA packaging. Remarkably, two genes, arranged such that one entirely overlaps the other and uses a different reading frame, encode interacting proteins. Several of the interactions reflect intramolecular associations of different domains of the same polypeptide, suggesting that the two-hybrid assay may be useful in the analysis of protein folding. This global approach to protein-protein interactions may be applicable to the analysis of more complex genomes whose sequences are becoming available.

Structure of rat DNA polymerase beta revealed by partial amino acid sequencing and cDNA cloning

A cDNA library of newborn rat brain poly(A)+ RNA in phage lambda gt11 was screened with a polyclonal antibody against chicken DNA polymerase beta. One positive phage was isolated and purified after testing 2 X 10(7) recombinants. This phage, designated lambda pol beta-10, contained an 1197-base-pair cDNA insert that corresponded to a mRNA with a poly(A) sequence at the 3' terminus and a single, long open-reading frame of 957 bases. The open-reading frame, starting 44 residues from the 5' end of the cDNA, predicted a 36,375-Da protein of 318 amino acids. Comparison of this deduced amino acid sequence with the partial sequence obtained with purified polymerase beta revealed a match of six tryptic peptides, involving a total of 47 amino acid residues. This confirmed the identity of the cDNA. Blot-hybridization analysis of newborn rat brain poly(A)+ RNA revealed a mRNA species of approximately the same size as the cDNA insert; in addition, a second mRNA species approximately equal to 4000 bases long was detected. Computer-derived secondary structure analysis of the enzyme predicted seven regions of alpha-helix distributed throughout and three regions of beta-sheet.