The primary purpose of this study is to study the maximum tolerated dose (MTD) of
orally-administered RP-3500 alone or in combination with talazoparib, a PARP inhibitor, in
patients with advanced solid tumors with ATR inhibitor-sensitizing mutations. This study will
also evaluate the safety and tolerability of RP-3500 alone or in combination with
talazoparib, examine both the pharmacokinetics (PK)and pharmacodynamics (PD)and investigate
its anti-tumor activity in solid tumors.