Windtree Presents New Istaroxime Phase 2b Study Analysis at the American College of Cardiology (ACC) Congress

WARRINGTON, Pa., April 6, 2020 /PRNewswire/ -- Windtree Therapeutics, Inc. (OTCQB: WINT), a biotechnology and medical device company focused on developing drug product candidates and medical device technologies to address acute cardiovascular and pulmonary diseases, today announced the presentation of a new subset analysis from a phase 2b study of istaroxime in patients hospitalized with acute heart failure (AHF) at the American College of Cardiology (ACC) 2020 virtual meeting. The company previously presented the overall results of the study where the primary endpoint demonstrated a significant improvement (p<0.05) in cardiac function at both istaroxime study doses. This post-hoc analysis characterized the responses between Caucasian and Asian patients. The istaroxime dose of 0.5 µg/kg/min produced a similar response on E/e', the primary study endpoint, and stroke volume index, an important measure of cardiac performance, in Asian and Caucasian patients. 

"We are very encouraged by the results from this phase 2b study subset analysis evaluating istaroxime, our novel, dual action agent that addresses both cardiac contractility and relaxation in patients with acute heart failure. As we continue to advance the istaroxime program in acute heart failure and early cardiogenic shock, data such as these play an important role in helping us understand dosing by seeing a similar effect across subgroups," said Steve Simonson, M.D., Chief Medical Officer at Windtree. "These data are consistent with previous analyses and suggest that, regardless of their race, patients saw a significant improvement in cardiac function, when treated with istaroxime."

The phase 2b study in 120 patients was designed to assess the safety and efficacy of 24-hour infusions of two doses of istaroxime (0.5 and 1.0 µg/kg/min), compared to placebo, in the treatment of patients with acute heart failure. The primary endpoint of this study was a change from baseline to 24 hours after start of infusion (Day 1) in E/e' with istaroxime 0.5 or 1.0 µg/kg/min vs. placebo. The E/e' ratio is a marker of the function of the left ventricle (LV) of the heart and was measured using doppler echocardiography read by a central laboratory.

Investigators of this study concluded that a 24-hour infusion of istaroxime was associated with significant improvements in cardiac function, in both dosing groups, with a mean E/e' of -4.55 for the 0.5 µg/kg/min group and -3.16 for the 1.0 µg/kg/min group, compared with mean placebo E/e' ratios of -1.55 and -1.08, respectively. The response was similar between races. The reduction of E/e' at 24 hours attained with istaroxime was slightly greater in Caucasian in comparison to Asian patients but not statistically significant (Caucasian -5.32±4.21 vs Asian -3.90±5.19; p=0.373). The observed increase of SVI with istaroxime treatment at 24 hours was of similar magnitude in Caucasian and Asian patients (Caucasian 4.78±7.15 ml/beat/m2 vs Asian 5.83±6.37 ml/beat/m2; p=0.653).

As has been previously reported, istaroxime was generally well tolerated. Istaroxime did not appear to be associated with an increase in risk for arrhythmias or increases in cardiac troponin T.  Cardiovascular related adverse events were 23 percent for placebo, 10 percent for istaroxime low dose, and 18 percent for istaroxime high dose with cardiac failure occurring in 3 percent, 5 percent and 8 percent of placebo, low and high dose of istaroxime patients, respectively.  The most common adverse drug reactions reported included pain at infusion site, generally associated with use of short catheters, and dose-related gastrointestinal adverse events in 5 percent, 10 percent and 35 percent of placebo, low and high dose istaroxime respectively.

About the ACC.20/WCC Congress
The American College of Cardiology together with the World Heart Federation joined together to host ACC.20/WCC Congress, which was a Virtual Congress this year as a result of the COVID-19 global pandemic.  The ACC connects cardiologists and cardiovascular specialists and professionals from more than 135 countries around the world to share the newest discoveries in treatment and prevention.  Videos, abstracts, slides and highlights from the presentations are available online through June 2020.

About Istaroxime
Istaroxime is a first-in-class, dual action, luso-inotropic agent in clinical development for the treatment of acute heart failure. Istaroxime is an intravenously administered agent with a potent positive inotropic agent that increases myocardial contractility through inhibition of Na+/K+-ATPase. In addition, it facilitates myocardial relaxation through activation of the SERCA2a calcium pump on the sarcoplasmic reticulum and reduction in cytoplasmic calcium in order to increase fill and follow on stroke volume. Windtree is pursuing clinical development of istaroxime in hospitalized patients with acute heart failure as well as in treating cardiogenic shock.  Istaroxime was awarded Fast Track designation for acute heart failure in August of 2019. 

About Windtree Therapeutics
Windtree Therapeutics, Inc. is a clinical-stage, biopharmaceutical and medical device company focused on the development of novel therapeutics intended to address significant unmet medical needs in important acute care markets. Windtree has  three lead clinical development programs and multiple pre-clinical programs spanning respiratory and cardiovascular disease states, including istaroxime, a novel, dual-acting agent being developed to improve cardiac function in patients with acute heart failure with a potentially improved side effect profile from existing treatments; AEROSURF^®, an innovative combination drug/device product candidate that is designed to deliver the Company's proprietary synthetic, peptide-containing surfactant non-invasively to premature infants with respiratory distress syndrome (RDS); and rostafuroxin, a novel precision drug product being developed to target hypertensive patients with certain genetic profiles in the important group of patients with resistant hypertension. Windtree also has multiple pre-clinical product candidates, including potential heart failure therapies delivered orally that are based on SERCA2a mechanism of action.

For more information, please visit the Company's website at www.windtreetx.com.

Forward-Looking Statements
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SOURCE Windtree Therapeutics, Inc.