RVT-1601 (sodium cromoglycate, previously PA101) for IPF

RVT-1601 (sodium cromoglycate, previously known as PA101) is an investigational inhalation therapy being developed by Roivant Sciences to potentially treat chronic cough in people with idiopathic pulmonary fibrosis (IPF).

It is delivered directly to the lungs as an inhaled mist using the proprietary handheld nebulizer, PARI eFlow.

Roivant acquired the rights to RVT-1601 from the previous developer, Patara Pharma, on Sept. 4, 2018. Following this announcement, Roivant launched Respivant Sciences, a new biopharmaceutical company focusing on therapeutics for respiratory diseases, to continue the development of RVT-1601.

How RVT-1601 works

IPF is a progressive lung disease, characterized by repeated scarring (fibrosis) that causes lung tissue to thicken. This results in an irreversible decrease in lung function over time. Among other symptoms, patients with IPF commonly have a chronic cough that can affect quality of life and contribute to disease progression.

The active component of RVT-1601, sodium cromoglycate, is often used to treat asthma. The drug’s exact function in reducing the symptoms of chronic cough is unknown, but RVT-1601 is thought to act as an immunomodulator, or compound that modifies the action of certain immune cells, such as mast cells. Mast cells may be involved in fibrosis in IPF. RVT-1601 could prevent or reduce damaging immune responses, such as inflammation, caused by mast cells that may contribute to coughing.

Used with its portable inhaler, the PARI eFlow device, RVT-1601 aims to bring a more effective amount of the drug into the lungs compared to previous sodium cromoglycate formulations. This could increase the efficiency and clinical benefit of the treatment.

RVT-1601 in clinical trials

Results from a proof-of-concept Phase 2 clinical trial (NCT02412020) were published in the scientific journal, The Lancet Respiratory Medicine. The randomized, double-blind trial assessed the safety and effectiveness of RVT-1601 compared to a placebo in 24 patients with IPF, at sites in the Netherlands and the U.K. Participants were assigned randomly either RVT-1601 or a placebo for two weeks, then switched treatment arms following a two-week wash-out period.

The results suggested that the treatment may be effective for IPF. After 14 days of treatment, IPF patients experienced a significant 31 percent reduction in average cough rate during the day compared to the placebo. This was measured using the Leicester cough monitor (LCM), which tracks coughing events using sound and can provide an objective report on the frequency of coughing during the monitoring period.

These results were supported by a patient-reported reduction in coughing, as well as a significant increase in coughing-related quality of life, based on the Leicester cough questionnaire. The study’s researchers concluded that RVT-1601 could benefit IPF patients in treating the symptoms of chronic cough.

The trial also assessed the effect of RVT-1601 in 28 patients with chronic idiopathic cough (CIC). The drug appeared to have no significant benefit in these patients.

RVT-1601 was determined to be well-tolerated in all patients, with no serious side effects reported during the trial. Roivant plans to start a Phase 2b clinical trial in the first quarter of 2019 to determine an optimal dose of RVT-1601 for IPF patients.


Pulmonary Fibrosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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