RTX-240 Monotherapy and in Combination With Pembrolizumab

Inclusion Criteria:

Signed written informed consent obtained prior to study procedures
Patients ≥18 years with an ECOG 0 or 1 (Parts 1, 2 and 4) or 0-2 (Part 3).
Relapsed/Refractory (R/R) or locally advanced, unresectable solid tumor for which no standard therapy exists (Parts 1, 2 and 4), or for which the patient is ineligible or has declined standard therapy or R/R, cytologically confirmed AML (Part 3).
Disease must be measurable per Response Evaluation Criteria
The shorter of 28 days or 5 half-lives must have elapsed since the completion of prior therapy, before initiation of study treatment.

Adequate Organ Function and Blood Cell Counts (Parts 1, 2, and 4) as defined by the protocol:

GFR ≥ 50 mL/min/1.73,
AST and ALT ≤ 3 × the ULN and total bilirubin ≤ 1.5 × ULN, in the absence of cancer within the liver
Or AST and ALT ≤ 5 × ULN and total bilirubin ≤ 3 × ULN, in the setting of primary or metastatic liver tumors.
ANC ≥ 1 × 10^3/μL without myeloid growth factor support for at least one week prior to enrollment
Platelet count ≥ 75 × 10^3/μL
Hemoglobin should be ≥ 9 g/dL without red blood cell transfusion for at least one week
Patients must have LVEF ≥ 45%
Patients enrolling into Part 2 of the study must be diagnosed with NSCLC, RCC, or anal cancers
Patients enrolling into Part 4 must be diagnosed with NSCLC or RCC
Patients enrolling into either Part 2 or 4 must have 2 or fewer prior treatment regimens. If patient received a prior PD-1/PD-L1-containing regimen, a prior response is required.

Exclusion Criteria:

Primary central nervous system (CNS) malignancy or CNS involvement, unless asymptomatic, previously treated, and stable without steroids (Parts 1, 2 and 4) or known CNS leukemia (Part 3).
Known hypersensitivity to any component of study treatment or excipients.
Positive antibody screen using institution's standard type and screen test.
Clinically significant, active and uncontrolled infection, including human immunodeficiency virus (HIV), Hepatitis B virus (HBV), or Hepatitis C virus (HCV).
Clinically significant coagulopathy, uncontrolled hypertension or autoimmune hemolytic anemia
Class III or IV cardiomyopathy per the New York Heart Association criteria
Leukemic blast count ≥ 25 x 10^3/µL (Part 3)
Concomitant conditions requiring active immunosuppression
History of clinically significant Grade 3 or higher immune related Adverse Event (irAE)
Prior malignancy within the past 3 years, with protocol specified exceptions
History of severe hypersensitivity to a PD-1/PD-L1 blocking Ab unless previously rechallenged successfully (Part 4)
Current noninfectious pneumonitis or a history of radiation pneumonitis or pneumonitis that required steroids, or Grade 2 or greater immune related pneumonitis, hepatitis, hypophysitis, or other endocrinopathy (Part 4)