Ionis Pharmaceuticals Inc (NASDAQ:IONS) shares are tumbling nearly 11% in Monday’s trading session, after the drug maker announced mixed results from a Phase 3 clinical trial, NEURO-TTR, assessing inotersen for the treatment of the inherited disorder familial amyloid polyneuropathy (FAP).

While the study met both primary efficacy endpoints demonstrating a statistically valid treatment benefit compared to placebo, there were four cases of thrombocytopenia that happened during the study. One of these cases resulted in death and two suffered serious injury, but recovered. The final patient left the study after experiencing minor thrombocytopenia.

Cowen analyst Eric Schmidt commented, “We are highly encouraged that inotersen met its co-primary endpoint of mNIS+7 and Norfold QoL-DN with high statistical significance. We believe inotersen will gain worldwide approvals and could become a meaningful revenue generator for Ionis. Investors are likely to debate the drug’s adverse event profile, and we are mindful of the safety issues and monitoring requirements that come with the drug’s benefit in this severe disease with no treatment options. Hence we expect much focus on the competitive landscape.”

Overall, Schmidt reiterates a Market Perform rating on Ionis Pharmaceuticals shares, without suggesting a price target.

According to TipRanks.com, which measures analysts’ and bloggers’ success rate based on how their calls perform, 5-star analyst Eric Schmidt has a yearly average return of 26.5% and a 56.5% success rate. Schmidt has a 77.6% average return when recommending IONS, and is ranked #64 out of 4561 analysts.

Out of the 12 analysts polled by TipRanks (in the past 12 months), 5 rate Ionis stock a Buy, 5 rate the stock a Hold and 2 recommend to Sell. With a return potential of 7%, the stock’s consensus target price stands at $44.60.