RegeneRx Biopharmaceuticals, Inc. (OTCBB: RGRX) saw its shares hurtle 5.5% in late Monday trading to 18.99 cents, on word of positive response to the company’s TB4 heart medication. Volume for the stock was 29,000 shares, which still trailed a daily average around 63,000.

The company, based out of Rockville, Md., announced that researchers have shown that TB4 has more extensive beneficial effects on the myocardium after heart attack than previously reported. The research team also confirmed previous reports that TB4 activates the Akt survival kinase and protects cardiac muscle cells from apoptosis (programmed cell death), that the infarct sizes were smaller and cardiac function significantly improved in mice receiving TB4, and that TB4-treated mice had a significant reduction in cardiac fibrosis (scarring) due to the reduction of collagen expression.

For the first time in a myocardial infarction model, researchers showed that TB4 suppresses NF-kB, a protein complex that regulates the expression of inflammatory molecules that cause damage during and after a heart attack. Previously published research showed that TB4 suppresses NF-kB after damage in the eye.

RegeneRx management was not available for comment.

RegeneRx is focused on the development of a novel therapeutic peptide, Thymosin beta 4, or TB4, for tissue and organ protection, repair and regeneration. RegeneRx currently has three drug candidates in clinical development and has an extensive worldwide patent portfolio covering its product candidates.