Sorrento Therapeutics Inc.          SRNE,         -11.70%        announced Monday a contract for the sale and distribution of up to 10 million its Covistix rapid COVID-19 virus detection tests in Mexico. That follows a previously announced deal for up to 5 million Covistix tests in Mexico, bringing the total number of tests to 15 million. The biopharmaceutical company said independent clinical testing of Covistix by a Mexico-based national institute showed a “very high sensitivity” of around 90% in an “all-comers” population, including asymptomatic COVID-19 virus carriers. Sorrento’s stock, which rallied 2.8% in premarket trading, has dropped 16.0% this year through Thursday, while the iShares Biotechnology ETF          IBB,         -0.65%        has gained 2.1% and the S&P 500          SPX,         +0.06%        has climbed 25.8%.