PA101 (sodium cromoglicate) is an investigational inhalation therapy being developed by Patara Pharma to potentially treat chronic cough in people with idiopathic pulmonary fibrosis (IPF).

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

How PA101 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 life quality and contribute to disease progression.

The active component of PA101, sodium cromoglicate, is often used to treat asthma. The drug’s exact function in reducing the symptoms of chronic cough is unknown, but PA101 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. PA101 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, PA101 aims to bring a more effective amount of the drug into the lungs compared to previous sodium cromoglicate formulations. This could increase the efficiency and clinical benefit of the treatment.

PA101 in clinical trials

Results from a proof-of-concept Phase 2 trial (NCT02412020) were published in the scientific journal, The Lancet Respiratory Medicine. The randomized, double-blind trial assessed the safety and efficacy of PA101 compared to a placebo in 24 patients with IPF. They were randomly assigned either PA101 or a placebo for two weeks, then switched treatment arms following a two-week wash-out period.

The results suggested that it 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 PA101 could benefit IPF patients in treating the symptoms of chronic cough.

The trial also assessed the effect of PA101 in 28 patients with chronic idiopathic cough (CIC). The drug appeared to have no significant benefit in these patients.

PA101 was seen to be well-tolerated in all patients, with no serious side effects reported due to its use during the trial. Patara plans to start a Phase 2b trial to determine an optimal dose of PA101 for IPF patients.


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