3.7.3 Lost to Follow-up A participant will be considered lost to follow -up if he or she fails to return for 4 scheduled visits and is unable to be contacted by the study site staff . The following actions must be taken if a participant fails to return to the clinic for a required study visit: • The site will attempt to contact the participant and reschedule the missed visit for within the next 2 weeks and counsel the participant on the importance of maintaining the assigned visit schedule and ascertain if the participant wishes to and/or should continue in the study. • Before a participant is deemed lost to follow -up, the investigator or designee will m ake every effort to regain contact with the participant (where possible, 3 telephone calls and, if necessary, an IRB approved certified letter to the participant’s last known mailing address or local equivalent methods). These contact attempts should be documented in the participant’s medical record or study file. • Should the participant continue to be unreachable, he or she will be considered to have withdrawn from the study with a primary rea son of lost to follow -up. 4 CONCOMITANT MEDICATIONS/MEASURES Any medications (other than those excluded by the clinical trial protocol) that are considered necessary to protect subject welfare or alleviate symptoms and will not interfere with the trial medication may be given at the Investigator’s discretion. Palliative radiotherapy delivered in a normal organ- spearing technique may be administered during the trial. The assessment of PD will not be based on the necessity for palliative radiotherapy. 4.1 T HE FOLLOWING TREATMENTS SHOULD NOT BE ADMINISTERED DURING THE TRIAL • Other immunotherapies or immunosuppressive drugs (for example, chemotherapy or systemic corticosteroids except for prophylaxis or treatment of allergic reactions, endocrine replacement therapy at low dose prednisone [≤ 10 mg daily] or equivalent, for the treatment of irAEs, or for short courses (≤ 14 days) as appropriate medical therapy for unrelated medical conditions (e.g., asthma). Steroids with no or minimal systemic effect (topical, inhalation) are allowed. • Prophylactic use of corticosteroids for infusion related reactions. Corticosteroid administration prior to CT scans in participants with intravenous contrast allergy is allowed. • Any live vaccine therapies for the prevention of infectious disease.