Pfizer Inc. (NYSE:PFE) is abandoning plans to develop an investigational antisense therapy known as vupanorsen for potential use for cardiovascular indications and severe hypertriglyceridemia (SHTG). The company had projected that vupanorsen could generate up to $3 billion in peak sales. Pfizer is returning development rights of the drug to Ionis Pharmaceuticals (NSDQ:IONS), from whom it…