Why Is Dicerna Stock Getting Slammed Today?

Dicerna Pharmaceuticals Inc (NASDAQ:DRNA) announced top-line results from PHYOX2 pivotal trial of nedosiran, RNAi therapeutic, for primary hyperoxaluria (PH).
The trial hit the primary endpoint for a pivotal study, but shares plummeted after efficacy data in a sought-after patient subpopulation showed no benefit over placebo.
PH is a family of ultra-rare genetic disorders that initially manifest with complications in the kidneys.
The PHYOX2 clinical trial included participants with PH subtypes 1 and 2 (PH1 and PH2).
The results showed benefit over placebo in patients with PH1, an indication with just one approved med, Alnylam Pharmaceuticals Inc's (NASDAQ:ALNY) Oxlumo, but not in PH2, one of two even rarer types of the disease without an approved therapy.
In a release, Dicerna called the results in five nedosiran PH2 patients "inconsistent."
Nedosiran works by inhibiting an enzyme that can cause an overproduction of oxalate in the blood and lead to chronic kidney stones.
But now, Dicerna says it will focus its regulatory efforts with a marketing application filing expected in Q4 of 2021. Meanwhile, the drug has another study in PH3.
Price Action: DRNA shares are down 28.8% at $27 during the premarket session on the last check Friday.
Related content: Benzinga's Full FDA Calendar.