Seven-year-old Josh Hardy, a first-grader from Fredericksburg, Virginia, is set to receive an experimental antiviral drug after his family’s campaign drew national attention. Chimerix, the company developing brincidofovir, reached an agreement with the Food and Drug Administration to begin a clinical trial, with Josh as its first patient.

Josh has survived several bouts of cancer since he was diagnosed with a rare kidney cancer at nine months old. A recent bone marrow transplant left his immune system severely weakened, and in February he developed an adenovirus infection that spread throughout his body. He is in critical condition at St. Jude Children’s Research Hospital in Memphis, experiencing heart and kidney failure.

Chimerix initially declined requests to provide the drug through compassionate use, a process that allows people with serious or life-threatening illnesses to request experimental medicines. The company said that supplying the drug individually could slow its efforts to bring it to market. Its president and CEO, Kenneth Moch, said Chimerix had received more than 80 compassionate-use requests for brincidofovir over the previous two years.

Josh’s parents and supporters pressed the company through social media, petitions, phone calls, emails and national television appearances. A “Save Josh” Facebook page attracted more than 15,000 followers, while local organizations and businesses also rallied around the family. Moch said the campaign brought attention to adenovirus infections and the need to study the drug, though he also reported that he and other Chimerix employees had received death threats.

The new open-label pilot study is expected to provide brincidofovir to 20 patients, beginning with Josh. The FDA also committed to work with Chimerix on the design of a larger Phase 3 study that would continue the pilot. Moch said the arrangement offered a way to help Josh and other patients in need.

Josh’s parents welcomed the decision, and supporters thanked Chimerix and the campaign’s participants. St. Jude expressed gratitude to the company, the FDA and others involved, while emphasizing that Josh’s condition remained critical and complex. The hospital also cautioned that the drug’s safety and effectiveness in children had not yet been established.