Roche (RHHBY) disclosed yesterday that the size of the RG6042 Phase 3 trial in Huntington's increased from 660 people to 801, Cantor Fitzgerald analyst Eliana Merle tells investors in a research note. Per company comments, this is driven by high patient demand and potential to increase statistical power, particularly for the Q16W dose, adds the analyst. Merle, however, thinks investors might see this change as suggesting the Phase 3 needed more patients for sufficient powering. For her part, the analyst continues to see Huntington's as a challenging indication to study in a clinical trial setting. The higher patient number should improve the likelihood of statistical success, however, says Merle. The analyst, who believes Huntington's is the key stock focus for Ionis Pharmaceuticals investors, keeps a Neutral rating on Ionis shares with a $65 price target.