Patupilone (Novartis, Basel, Switzerland) was administered every 3 weeks either as a bolus (20 min), 1-day continuous infusion (24 h) or 5-day continuous infusion (16-h per day over 5 days) at dose levels of 6.5, 7.0, 7.5, 8.0, 9.0 and 10.0 mg/m2 until disease progression, unacceptable toxicity or withdrawal of consent.

Cortices were dissected from embryonic 15.5mice and incubated in papain (20U/mL, Worthington) containing DNase (10 U/𝜇L, Sigma) for 40min at 37∘C. Enzyme-digested cortices were washed three times with MEM (Cellgro) containing 10% heat inactivated fetal bovine serum (Hyclone) and dissociated in culture medium. Dissociated neurons were then centrifuged to remove the supernatant and counted cells were plated on glass coverslips coated with 100 𝜇g/mL poly-D-lysine (Sigma) and grown in Neurobasal A (Gibco) medium containing Glutamax (1%, Thermo Fisher Scientific) and B27 (2%, Thermo Fisher Scientific) supplements. 5 hr after plating, neurons were treated with epothilone B (from 1 pM to 1 𝜇M and 10pM or 1 nM) for 3 days in low-density cultures (5 x 104 cells in 1.9 cm2) or overnight (17–19hr) in high-density cultures (2 x 105 cells in 1.9 cm2). Neurons were then fixed and analyzed for viability, axon growth, and microtubule structure.