Presatovir in Hematopoietic Cell Transplant Recipients With Respiratory Syncytial Virus (RSV) Infection of the Lower Respiratory Tract

Study Overview
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Brief Summary
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The primary objective of this study is to evaluate the effect of presatovir on respiratory syncytial virus (RSV) viral load in autologous or allogeneic hematopoietic cell transplant (HCT) recipients with an acute RSV lower respiratory tract infection (LRTI).

Official Title
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A Phase 2b, Randomized, Double-Blind, Placebo-Controlled Multi-Center Study Evaluating Antiviral Effects, Pharmacokinetics, Safety, and Tolerability of GS-5806 in Hematopoietic Cell Transplant (HCT) Recipients With Respiratory Syncytial Virus (RSV) Infection of the Lower Respiratory Tract

Conditions
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Respiratory Syncytial Virus Infection

Intervention / Treatment
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* Drug: Presatovir
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Received an autologous or allogeneic HCT using any conditioning regimen Evidence of new abnormalities on chest X-ray obtained < 48 hours prior to screening, determined to be consistent with LRTI by the local radiologist, relative to the most recent previous chest X-ray. If chest X-ray is not available, a chest X-ray must be obtained for screening. Documented RSV in both the upper (eg, nasal swab, nasopharyngeal swab, nasal wash) and lower (eg, induced sputum, bronchoalveolar lavage, lung biopsy, but not spontaneous sputum) respiratory tract as determined by local testing (eg, polymerase chain reaction, direct fluorescence antibody, respiratory viral panel assay, or culture). All samples must have been collected ≤ 6 days prior to Day 1, or as determined at screening as per protocol. An informed consent document signed and dated by the participant or a legal guardian of the participant and investigator or his/her designee. A negative urine or serum pregnancy test is required for female participants (unless surgically sterile or greater than two years post-menopausal) Male and female participants of childbearing potential must agree to contraceptive requirements as described in the study protocol Willingness to complete necessary study procedures and have available a working telephone or email Key Exclusion Criteria: Related to concomitant or previous medication use: Use of non-marketed (according to region) investigational agents within 30 days, OR use of any monoclonal anti-RSV antibodies within 4 months or 5 half-lives of screening, whichever is longer, OR use of any investigational RSV vaccines after HCT Use of a moderate or strong cytochrome P450 enzyme inducer including but not limited to rifampin, St. John's Wort, carbamazepine, phenytoin, efavirenz, bosentan, etravirine, modafinil, and nafcillin, within 2 weeks prior to the first dose of study drug Related to medical history: Pregnant, breastfeeding, or lactating females Unable to tolerate nasal sampling required for this study, as determined by the investigator Known history of HIV/AIDS with a CD4 count <200 cells/μL within the last month History of drug and/or alcohol abuse that, in the opinion of the investigator, may prevent adherence to study activities Related to medical conditions: Requiring invasive mechanical ventilation at the time of randomization Documented to be positive for other respiratory viruses (limited to influenza, parainfluenza, human rhinovirus, adenovirus, human metapneumovirus, or coronavirus), from the lower respiratory tract sample as determined by local testing Clinically significant bacteremia or fungemia within 7 days prior to screening that has not been adequately treated, as determined by the investigator Clinically significant bacterial, fungal, or viral pneumonia within 2 weeks prior to screening that has not been adequately treated, as determined by the investigator Excessive nausea/vomiting at screening, as determined by the investigator, or an inability to swallow pills that precludes oral administration of the investigational medical product (for individuals without an NG tube in place) Any condition which, in the opinion of the investigator, would prevent full participation in this trial or would interfere with the evaluation of the trial endpoints Related to laboratory results: Creatinine clearance < 30 mL/min (calculated using the Cockcroft-Gault method) Clinically significant aspartate aminotransferase/alanine aminotransferase, as determined by the investigator Clinically significant total bilirubin, as determined by the investigator Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Presatovir<br>Participants will receive presatovir on Days 1, 5, 9, 13, and 17, with follow-up visits through Day 28, and may continue in an optional extended monitoring phase with visits through Day 56. | Drug: Presatovir<br>* Presatovir 200 mg (4 × 50 mg tablets) administered orally or via nasogastric (NG) tube<br>* Other names: GS-5806;|
| Placebo Comparator: Placebo<br>Participants will receive placebo to match presatovir on Days 1, 5, 9, 13, and 17, with follow-up visits through Day 28, and may continue in an optional extended monitoring phase with visits through Day 56. | Drug: Placebo<br>* Placebo to match presatovir administered orally or via nasogastric tube<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time-weighted Average Change in Nasal Respiratory Syncytial Viral (RSV) Load From Baseline to Day 9 | The time-weighted average change, often referred to as the DAVG, provides the average viral burden change from baseline. The mean values presented were calculated using the ANCOVA model and are adjusted for baseline value and stratification factors. | Baseline to Day 9 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Supplemental O2-Free Days Through Day 28 |  | Up to Day 28 | 
| Percentage of Participants Developing Respiratory Failure Requiring Mechanical Ventilation Through Day 28 |  | Up to Day 28 | 
| Percentage of All-Cause Mortality Among Participants Through Day 28 |  | Up to Day 28 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Respiratory Syncytial Virus (RSV), Antiviral, Hematopoietic Cell Transplant (HCT), Lower respiratory tract infection