Seven-year-old Josh Hardy, who was critically ill with a widespread adenovirus infection, was set to receive an experimental antiviral drug after its maker, Chimerix, reached an agreement with the Food and Drug Administration to begin a clinical trial. Josh would be the first of 20 patients in the open-label study of brincidofovir, with the FDA also agreeing to work with the company on a larger Phase 3 study.

Josh, a first-grader from Fredericksburg, Virginia, had survived several bouts of cancer since he was diagnosed with a rare kidney cancer as a baby. A recent bone marrow transplant left his immune system severely weakened, and the adenovirus spread through his body. At St. Jude Children’s Research Hospital in Memphis, he was in intensive care with heart and kidney failure.

His family and doctors had sought access to brincidofovir, which was not yet widely available or approved by the FDA. Chimerix initially declined, saying that providing the drug individually could slow efforts to bring it to market. Company president Kenneth Moch said Chimerix had received more than 80 requests for compassionate use of the drug over two years and had been working with the FDA on a way to reach more patients.

The family’s appeal drew national attention through television coverage, social media, petitions and local support. A “Save Josh” Facebook page attracted more than 15,000 followers, and supporters sent calls, emails and tweets to Chimerix. Moch said the campaign also led to death threats against him and other employees.

Josh’s parents celebrated the announcement and thanked supporters and Chimerix. St. Jude expected the medication within 48 hours but cautioned that its safety and effectiveness in children had not been established and that Josh’s condition remained critical and complex.