The CDC recently issued a warning that Respiratory Syncytial Virus (RSV), a common and highly contagious lung infection that can cause bronchitis and pneumonia, is on the rise in the Southeastern United States – and the very young and the elderly are the most at risk of developing severe incidences of RSV. 

Every year, there are over 2 million outpatient (non-hospitalized) cases of RSV in children under 5, and RSV is the leading cause of hospitalizations for young children. There are up to 80,000 hospitalization cases for children under 5, and there are also up to 160,000 cases of patients over 65 getting hospitalized with RSV. Up to 300 children under 5 and 10,000 adults over 65 die of RSV annually. Despite this serious disease, there were no vaccines or good treatment options until recently.

The recently approved vaccines from GSK plc (NYSE:GSK) and Pfizer (NYSE:PFE) also have severe limitations. These vaccines are only for use in patients aged 60 and over. However, these vaccines can involve side effects, including atrial fibrillation, Guillain-Barré syndrome and another potentially related disorder. A recently approved vaccine for pregnant women to protect the newborn infant upon birth has the risk of preterm births. 

In July 2023, the FDA also approved Beyfortus, an antibody treatment for children delivered as an injection to help prevent the development of RSV. Beyfortus was developed by Sanofi (NASDAQ:SNY) and AstraZeneca (NASDAQ:AZN). It is expected to be better than a previously approved antibody (palivizumab, trade name Synagis, developed by MedImmune, now marketed by SOBI – Swedish Orphan Biovitrum) for the same indication. Like the vaccines, however, there are side effects associated with these protective antibody treatments, which can include anaphylaxis, a severe allergic reaction. 

The market for therapeutics for RSV was worth $1.8 billion in 2022 and will reach $8.73 billion by 2031 at a compound annual growth rate (CAGR) of 18.9% during the forecast period, according to a recent report from Growth Plus Therapeutics. Note that there were no real treatments, only one protective antibody, Synagis, available in 2022. 

The therapeutic used for treating RSV is Ribavirin, a highly toxic compound also used as a therapy for hepatitis C. However, Ribavirin carries with it some severe side effects, including the destruction of red blood cells, leading to liver, kidney and spleen toxicities and failures – which limit its use to patients with a high risk of progressively severe RSV. The primary concerning side effect of Ribavirin is anemia, a decrease in red blood cells that can cause a drop in hemoglobin. Ribavirin-induced anemia can manifest within two weeks of starting the therapy and can get worse as the drug dosage increases.

NanoViricides (NYSE:NNVC), a leading developer of antiviral treatments through its nanomedicines platform, is developing a safe and effective alternative therapeutic for RSV. Its drug candidate, NV-387, has already been shown to not have the toxicity or side effects associated with Ribavirin, according to the company. It reports that in the recent pre-clinical animal study, NV-387 almost matched the efficacy of Ribavirin with no toxicity. This animal study was designed to mimic the lethal lung pneumonia in infants caused by RSV infection.