Wells Fargo analyst Jim Birchenough noted that Ionis (IONS) partner Biogen (BIIB) made comments that suggested slowing growth for Spinraza in the future due to technical challenges to dosing in patients with spinal surgeries. However, he understands that Ionis has seen initial success in dosing patients with type 2 SMA and spinal surgery and believes these patients will be viable candidates for Spinraza even though the process is more involved. Birchenough, who thinks the drug's impressive growth and broadening use and reimbursement more than offsets a hurdle dosing certain patients, raised his price target on Ionis shares to $75 and keeps an Outperform rating on the stock.