Pulmagen med passes phase 2 asthma test, seeks partner for late-stage trials

U.K.-based Pulmagen says its med appears to work best in a subgroup of asthma patients with a severe form of asthma

U.K.-based biotech Pulmagen says its oral CRTh2 antagonist has posted positive results for its respiratory drug in a midstage trial.

Data for PTR-36 (a.k.a. ADC3680), a once daily, orally administered CRTh2 antagonist, was tested in patients with asthma and eosinophilic asthma.

The eosinophilic phenotype is a fairly narrow subpopulation of asthma patients who struggle to control their asthma, even when taking high doses of medicine to help stop attacks.

Although a subpop, GSK already has approval for its asthma mAb Nucala (mepolizumab), which recently gained an EMA and FDA green light for severe eosinophilic asthma.

Analysts have estimated that Nucala should see sales in excess of $500 million a year, and potentially $1 billion-plus at peak.

Israeli generic giant Teva is also in the game, and back in March gained FDA approval for its IL-5 inhibitor mAb Cinqair (reslizumab), also for the maintenance of severe asthma in patients with the eosinophilic phenotype.

AstraZeneca is currently bringing up the rear, recently posting positive data for benralizumab in severe asthma patients with an eosinophilic phenotype.

Pulmagen’s med works differently, however, and its latest data, coming out of a 16-week phase 2 double blind, placebo controlled study, was conducted in Japan by Tokyo-based Teijin Pharma Limited, under the terms of a licensing deal struck between the pair four years’ ago.

Pulmagen said now, however, it is “seeking a global partner for late stage clinical development,” which it will need to prove that the drug works. 

The “exploratory” test was set up as a double-blind, randomized, placebo-controlled study with inhaled corticosteroid (ICS) dose tapering and cessation. 

Just under 160 patients with mild to moderate asthma had their long-acting β-agonists (LABA) discontinued and were standardised on a medium dose of ICS for 28 days prior to randomisation. 

At the start of the 16-week treatment, the dose of ICS was reduced and patients were randomized to two doses of PTR-36 (5mg or 20mg once daily) or to placebo for an initial 28 days, after which the ICS was fully discontinued. Patients then remained on PTR-36 or placebo for a further 12 weeks.

PTR-36, an oral chemoattractant receptor-homologous molecule expressed on Th2 cells receptor antagonist, showed a statistically significant difference when compared to placebo at both doses when it came to change in morning peak expiratory flow (mPEF).

A number of secondary endpoints including time to first exacerbation, asthma control questionnaire and use of short acting bronchodilators in the total population also achieved statistical significance, the biotech said in a statement. Full details were not however shared in the release.

While a statistically significant difference in the primary endpoint (i.e., mPEF) between both doses of PTR-36 and placebo was observed in the general study population, the biotech said that when it drilled down into the subgroups, this revealed “that the effect of treatment with PTR-36 was greatest in patients with eosinophilic disease, suggesting better asthma control when treated with PTR-36.” 

Dr. Mary Fitzgerald, executive VP of respiratory at Pulmagen, said: “There remains an unmet medical need for severe eosinophilic asthma patients who are uncontrolled on standard of care therapies.  This is a significant population of patients who are at the greatest risk of exacerbations, hospitalisation and death. 

“Patients understand this and report a significant impact of their asthma on everyday functioning and quality of life. We have learned much about the importance of this mechanism and its utility over the last few years and look forward to progressing our global partnering discussions to continue the rapid development of the programme.”