shares of longeveron inc lgvn blasted 1209 higher on very active morning trading thursday after the biotechnology company said its lomecelb for the treatment of a congenital heart defect in infants hypoplastic left heart syndrome affecting about 1000 babies a year was granted rare pediatric disease rpd designation by the food and drug administration trading volume exploded to 1120 million shares compared with the fullday average of about 110000 shares the stock was both the biggest gainer and most active on major us exchanges the company said lomecelb is currently being evaluated in a phase 2 trial despite the rally the stock which went public in february was still trading well below the initial public offering price of 10 a share the stock has now climbed 777 over the past three months while the ishares nasdaq biotechnology etf ibb has slipped 88 and the sp 500 spx has gained 64