Plaintiffs filed more than 350 products liability cases last month in Delaware state court against AstraZeneca Pharmaceuticals L.P. over the anti-psychotic drug Seroquel — a surge exceeding the total number of cases filed there in the last two years.

Plaintiffs lawyers contend that there is nothing behind the spike in filings. They point out that Delaware is Wilmington-based AstraZeneca’s home state and that the cases would have been filed eventually anyway.