This Study is a FIH Study Which is Required to Understand the PK Characteristics, MTD, RP2D and Safety Profile.

there are seven doses(1mg-160mg) in this part. The subjects will receive RJK-RT2831 injection twice a week by intravenous push or intravenous infusion for 4 weeks until the end of one dosing cycle (28 days). After one dosing cycle, if the subject tolerates, the subject will continue to receive treatment until the researcher believes that the subject no longer benefits, or the subject has disease progression, unacceptable toxicity, withdraws informed consent, dies, is lost to follow-up, or starts new anti-tumor treatment (whichever occurs first).

there are four doses in this part. The subjects will be randomized in a 1:1 ratio to receive one dose level of RJK-RT2831 intravenous infusion twice a week for 4 weeks until the end of one dosing cycle (28 days).After one dosing cycle, if the subject tolerates, the subject will continue to receive treatment until the researcher believes that the subject no longer benefits, or the subject has disease progression, unacceptable toxicity, withdraws informed consent, dies, is lost to follow-up, or starts new anti-tumor treatment (whichever occurs first).