An Observational Study Evaluating the Safety, Tolerability, and Efficacy of Treatment of SM04690 or Placebo Previously Injected in the Target Knee Joint of Subjects With Moderately to Severely Symptomatic Osteoarthritis

Inclusion Criteria:

- Completion of scheduled end-of-study visit of Samumed-sponsored SM04690-OA phase 2 or
phase 3 studies

- Full understanding of the requirements of the study and willingness to comply with all
study visits and assessments

- Subjects must have read and understood the informed consent form, and must have signed
it prior to any study-related procedure being performed

Exclusion Criteria:

- Unable to undergo the radiograph procedures detailed within the protocol

- Partial or complete joint replacement in the target knee

- Subjects who are immediate family members (spouse, parent, child, or sibling;
biological or legally adopted) of personnel directly affiliated with the study at the
investigative site, or are directly affiliated with the study at the investigative
site

- Subjects employed by Samumed, LLC, or any of its affiliates or development partners
(that is, an employee, temporary contract worker, or designee) responsible for the
conduct of the study