Study of TSR-033 With an Anti-PD-1

This is a multi-center, open-label, first-in-human, Phase 1 study evaluating the anti-LAG-3
antibody of TSR-033 alone and in combination with anti-PD-1. The study will be conducted in 2
parts, with Part 1 consisting of dose escalation to determine the RP2D of TSR-033 as a single
agent (Part 1a) and in combination with an anti-PD-1 antibody (Part 1c). RP2D decisions will
be based on the occurrence of dose-limiting toxicities (DLTs), PK, as well as PDy data. These
regimens will be evaluated in patients with advanced solid tumors who have limited available
treatment options as determined by the Investigator.

Part 2 of the study will evaluate the anti-tumor activity of TSR-033 in combination with an
anti-PD-1 in patients.

Key Inclusion Criteria Part 1:

- Patients with advanced (unresectable) or metastatic solid tumor and have disease
progression after treatment with available therapies that are known to confer clinical
benefit or who are intolerant to treatment.

- Patients must have tumor tissue available.

- Female patients must have a negative serum or urine pregnancy test or be of
non-childbearing potential.

- Eastern Cooperative Oncology Group (ECOG) performance status of less than or equal to
1 and adequate organ function.

Key Inclusion Criteria Part 2:

- Patients must have not been previously treated with an anti - LAG - 3, anti - PD - 1,
anti - PD - L1, or anti - PD - L2 antibody.

Key Exclusion Criteria for all:

- Known uncontrolled central nervous system metastases and - or carcinomatous
meningitis.

- History of human immunodeficiency virus (HIV), active Hepatitis B or Hepatitis C.

- Participated in another investigational study (drug or device) within 4 weeks of first
dose.

- Received prior anticancer therapy within 21 days of first dose.

- Not recovered from Adverse Events (AEs) and - or complications from major surgery
prior to first dose.

- Vaccine within 7 days of planned start of study treatment.