Study of the CD40 Agonistic Monoclonal Antibody APX005M

APX005M-001 is an open-label study and comprises a dose-escalation portion of approximately 8
dose level cohorts, plus an expansion cohort.

Eligible subjects with solid tumors will receive intravenous APX005M every 3 week, every 2
week or every 1 week until disease progression, unacceptable toxicity or death, whichever
occurs first.

Study objectives include:

- Evaluate safety of APX005M

- Determine the maximum tolerated dose of APX005M

- Determine the pharmacokinetic parameters of APX005M: the maximal drug concentration
(Cmax), area under the curve of serum concentration over time (Area Under the Curve/
AUC), and half-life (t½).

- Preliminary assessment of clinical response

Key Inclusion Criteria:

- Histologically documented diagnosis of solid tumor

- For subjects in the every 2 week and every 1 week dosing cohorts histologically or
cytologically documented diagnosis of urothelial carcinoma, melanoma, squamous cell
carcinoma of the head and neck, non-small cell lung cancer, or any solid tumor with
high microsatellite instability status (MSI-high)

- No known effective therapy options are available

- Measurable disease by RECIST 1.1

- ECOG performance status of 0 or 1

- Adequate bone marrow, liver and kidney function

- No toxicities related to prior treatment related toxicities with the exception of
alopecia and neuropathy

- Negative pregnancy test for women of child bearing potential

Key Exclusion Criteria:

- Any history of or current hematologic malignancy

- Major surgery or treatment with any other investigational agent within 4 weeks

- Uncontrolled diabetes or hypertension

- History of arterial thromboembolic event

- History of congestive heart failure, symptomatic ischemia, conduction abnormalities
uncontrolled by conventional intervention, or myocardial infarction

- Active known clinically serious infections