Companion Study for Patients Who Completed Participation in a REGN2810 (Anti-PD-1) Clinical Study

The target population for this study is patients who have participated in any REGN2810
clinical study.

Inclusion Criteria for Patients Receiving Re-treatment:

1. Tolerated prior treatment with REGN2810 with no unacceptable toxicity (except select
reversible irAEs) requiring discontinuation of REGN2810

2. Developed documented progressive disease after first demonstrating clinical benefit
from their initial treatment

3. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1

4. ≥18 years old

5. Hepatic function:

- Total bilirubin ≤ 1.5 x upper limit of normal (ULN; if liver metastases ≤ 3 x
ULN)

- Transaminases ≤ 3 x ULN (or ≤ 5.0 x ULN, if liver metastases)

- Alkaline phosphatase (ALP) ≤ 2.5 x ULN (or ≤ 5.0 x ULN, if liver metastases)

- For patients with hepatic metastases or hepatic malignancies, exclude patients
with concomitant 3 x ULN ≤ aspartate aminotransferase (AST) and/or alanine
aminotransferase (ALT) ≤ 5 x ULN and 1.5 x ULN ≤ total bilirubin ≤ 3 x ULN

6. Renal function: Serum creatinine ≤ 1.5 x ULN

7. Bone marrow function:

- Hemoglobin ≥ 9.0 g/dL

- Absolute neutrophil count (ANC) ≥ 1.5 x 10^9/L

- Platelet count ≥ 75 x 10^9/L

Inclusion Criteria for Patients who Will not Receive Re-treatment:

Patients must have completed participation in any REGN2810 clinical study.

Exclusion Criteria:

A patient who meets any of the following criteria will be excluded from receiving
re-treatment with REGN2810:

1. Ongoing or recent (within 5 years) evidence of significant autoimmune disease that
required treatment with systemic immunosuppressive treatments, which may suggest risk
for irAEs.

2. Patients who experienced an irAE in while participating in another REGN2810 protocol
who were unable to have their corticosteroid dose reduced to <10 mg per day
prednisone equivalent within 12 weeks of toxicity.

3. Patients who developed ≥ Grade 2 uveitis in a prior REGN2810 protocol

4. Immunosuppressive corticosteroid doses (> 10 mg prednisone daily or equivalent)
within 4 weeks prior to the first dose of REGN2810

5. Active infection requiring therapy, including known infection with human
immunodeficiency virus, or active infection with hepatitis B or hepatitis C virus.

6. History of pneumonitis within the last 5 years.

7. Any investigational or antitumor treatment within 30 days prior to the initial
administration of REGN2810.

8. History of documented allergic reactions or acute hypersensitivity reaction
attributed of Grade ≥ 3 severity during or directly following an REGN2810 infusion

9. Known allergy to doxycycline or tetracycline. (precaution due to presence of trace
components in REGN2810)

10. Breast-feeding

11. Positive serum pregnancy test

12. History within the last 5 years of an invasive malignancy other than the one treated
in this study, with the exception of resected/ablated basal or squamous-cell
carcinoma of the skin or carcinoma in situ of the cervix, or other local tumors
considered cured by local treatment.

13. Acute or chronic psychiatric problems that, under the evaluation of the investigator,
make the patient ineligible for participation

14. Unwilling to practice adequate contraception during the study until 6 months after
the last dose of study drug