A phase 1 trial of 4-(N-(S-penicillaminylacetyl)amino)-phenylarsonous acid (PENAO) in patients with advanced solid tumours.

PENAO was administered by CIVI at dose levels up to 9 mg/m2/day with only one DLT noted. Pharmacokinetic studies invalidated the rationale for continuous dosing and led to discontinuation of the trial without defining a RP2D. Future clinical development of PENAO will use intermittent dosing schedule, alone and in combination with rapamycin.