Ionis' IONIS-HTTRx reduces mutant HTT protein in Phase I/II for HD

Ionis Pharmaceuticals Inc. (NASDAQ:IONS) said IONIS-HTTRx (RG6042) significantly reduced mutant huntingtin (HTT) protein in the CSF of patients with early stage Huntington’s disease vs. placebo in a Phase I/II trial. Ionis said Roche (SIX:ROG; OTCQX:RHHBY) is planning a pivotal trial of the antisense molecule targeting HTT to treat HD, but the partners did not disclose details.

In the 46-patient trial, 90 and 120 mg doses of intrathecal IONIS-HTTRx, the two highest tested doses, given every four weeks for four doses each reduced mean mutant HTT protein in the CSF by about 40% from baseline vs. an increase for placebo (p<0.01 for both). Ionis said mutant HTT protein levels continued to decline at the last measurement at three months and that it expects the maximum reduction in mutant HTT protein levels at about six months after the first dose. IONIS-HTTRx was well tolerated with no serious adverse events reported...