Isis Pharmaceuticals Inc. (NASDAQ:ISIS) didn't wait for investors to learn launch details of hypercholesterolemia drug Kynamro mipomersen. Instead, the biotech took advantage of recent share price gains to raise $171 million in the largest follow-on this quarter.

In March, the Genzyme Corp. unit of Sanofi (Euronext:SAN; NYSE:SNY) launched Kynamro in the U.S. to treat homozygous familial hypercholesterolemia (hoFH). Neither Isis nor Genzyme, which has rights from Isis, divulged details in earnings announcements this month.