I don't know much about Summer Street, but they made ISIS one of their top mid cap picks.
Summer Street Research - Published Jan 8, 2010 -
Overall large cap biotech underperformed the market in 2009. Valuations are attractive for the top 5 companies, however each company has issues, and without generalists coming back to the sector the shares may stay in a trading range. We are sticking with our BUY on GILD, NEUTRAL on CELG, and upgrading BIIB to NEUTRAL from SELL. We expect M&A to continue, but we expect no mega mergers. Our top mid-cap picks are BMRN and ISIS. Both are well capitalized, cash flow positive or near to it, and have important trial results that we expect to be positive this year. Our top small-cap picks are AFFY, AVNR and ARNA, as we expect positive pivotal results for Hematide with a NDA filing by YE:10,Zenvia approval, and lorcaserin approval. We are more cautious on our more richly valued companies AMAG, AMLN, HGSI, VRTX, and SVNT, which may not meet street expectations.
As far as why I'm optimistic. ISIS is the most exciting company in the bio space, it got a bad rap due to the failures with 1st generation antisense, but this is about to change. ISIS currently uses second generation antisense technology 2.0/2.2 & 2.5 will be in the clinic next year which allows for oral delivery.
-The stock was knocked down from the $20-$18 range to the $10 level for no reason. ISIS reported Phase III results on Mipomersen in a homozygous FH population which were actually very good, but the street thought differently. Anytime you talk about elevations in liver enzymes then the street runs for good reason, but this is the exception. No violations in Hy's law has occurred & the patients have returned to normal levels in a short time when taken off drug. You get elevations with statins also so this has not been a concern with the experts. You have to understand the type of population in which the clinical results were recently reported.
As far as competition. There really is none at this point. The competitors are where ISIS was with 1st generation. They haven't figured out the drug delivery, but they may be getting closer. This is an excellent blog if you want to learn about competition in the space. http://rnaitherapeutics.blogspot.com/
If you want to learn about ISIS or ask questions then I suggest the IV board. Its got some very knowledgeable posters.