The litigation over Risperdal has not only become the largest mass tort program in Philadelphia's busy court system, it has also nearly tripled in size from about 2,000 cases at the start of the year to more than 5,500 as of June.

According to the latest statistics from the Philadelphia Court of Common Pleas, litigation over the anti-psychotic drug Risperdal jumped from being 31.4 percent of the Complex Litigation Center's inventory as of Jan. 1 to 55.8 percent as of June 14. That number represents a 185 percent increase from the 1,945 at the start of the year, and is due to 3,617 new cases being filed in the mass tort since January. As of early June, 5,548 Risperdal cases were pending.

Attorney Thomas R. Kline, who, as part of a consortium of attorneys from Kline & Specter, Sheller P.C. and Arnold & Itkin, is handling approximately three-quarters of the Risperdal docket in Philadelphia, said the recent influx was caused mostly by a tolling agreement that was terminated last year.