Study to Evaluate Safety, PK, PD, Immunogenicity & Antitumor Activity of MSC-1 in Patients With Adv Solid Tumors

MSC-1 is a first-in-class, humanized monoclonal antibody (IgG1) which binds to the
immunosuppressive human cytokine Leukemia Inhibitory Factor (LIF), and is intended to treat
adult patients with advanced solid tumors. LIF is a pleiotropic cytokine involved in many
physiological and pathological processes including the promotion of an immunosuppressive
environment. In cancer, it is hypothesized that LIF expressing malignancies co-opt this
activity, creating an immunosuppressive tumor microenvironment as well as promoting the
activity of cancer-initiating cell(s) (CICs). LIF is highly expressed in a subset of tumors
across multiple solid tumor types.

During dose escalation, patients with Advanced Solid Tumors will be treated with MSC-1 with
the primary objective of determining the safety and tolerability of MSC-1 and defining an
appropriate dose for further evaluation in dose expansion. MSC-1 will be administered
intravenously (IV) until disease progression, unmanageable toxicity, withdrawal of consent or
study termination.

In dose expansion, up to 4 parallel cohorts of patients with LIF-High tumors (NSCLC, Ovarian
Cancer, Pancreatic Cancer), and a cohort of mixed Solid Tumors (referred to as the "basket
cohort"), may be treated at the recommended expansion dose to further characterize the
safety, tolerability, PK, PD and anti-tumor activity of MSC-1.

Inclusion Criteria (All patients):

- Confirmed Advanced Unresectable Solid Tumor

- Measurable disease by RECIST 1.1 by CT or MRI

- Documented disease progression on or following last line of therapy

- Archival tumor sample for submission

- ECOG performance status 0 or 1

- Resolution of all acute, reversible toxic effects of prior therapy or surgical
procedures to at least grade 1 (except alopecia and peripheral neuropathy to at least
grade 2)

- Adequate organ function

- A limited number of patients enrolled in Dose Escalation may be required to agree to
pre- and on-treatment tumor biopsies

Inclusion Criteria (Dose Expansion patients only)

- LIF- High NSCLC, Ovarian Cancer, or Pancreatic Cancer for the tumor-specific cohorts
or Advanced Solid Tumor for the basket cohort as assessed by tumor tissue evaluation
by IHC

- All patients enrolled in Dose Expansion must agree to undergo pre- and on-treatment
tumor biopsies

Exclusion Criteria (All Patients):

- Systemic anti-cancer therapy within 4 weeks or 5 half-lives prior to study entry

- Previous or concurrent malignancy that could affect compliance with protocol or
interpretation of results

- Clinically significant, unstable cardiovascular or pulmonary disease as specified in
detail in the study protocol

- History of acquired or congenital immunodeficiency syndrome or receiving
immunosuppressive therapy

- Uncontrolled infections or serologically positive HIV or hepatitis B or C infection

- Other severe acute or chronic medical or psychiatric condition or laboratory
abnormality that may increase risk associated with study participation or interfere
with interpretation of study results