Study of REGN4659 in Combination With Cemiplimab in Patients With Advanced or Metastatic Non-Small Cell Lung Cancer (NSCLC)

KEY Inclusion Criteria:

1. Patients with histologically or cytologically documented squamous or non-squamous
NSCLC with unresectable stage IIIB or stage IV disease

2. Combination dose escalation cohorts: Treatment-experienced patients who have received
no more than 3 lines of systemic therapy including no more than 2 lines of cytotoxic
chemotherapy, and for whom no available therapy is expected to convey clinical
benefit.

3. Cemiplimab monotherapy cohort: Anti-PD-1/PD-L1 naïve patients who have received 1 to 2
prior lines of cytotoxic chemotherapy including a platinum doublet-containing regimen

4. Expansion cohort(s): Anti-PD-1/PD-L1 experienced patients who have progressed while
receiving therapy or within 6 months of stopping therapy for stage III or IV disease.
Patients must not have permanently discontinued anti-PD-1/PD-L1 therapy due to
treatment related AE. Patients must have received one line of anti-PD--1/PD-L1
immunotherapy. Patients may also have received one line of chemotherapy

KEY Exclusion Criteria:

1. Expansion cohort(s) only: Patients who have never smoked, defined as smoking ≤100
cigarettes in a lifetime

2. Active or untreated brain metastases or spinal cord compression. Patients are eligible
if central nervous system (CNS) metastases are adequately treated and patients have
neurologically returned to baseline (except for residual signs or symptoms related to
the CNS treatment) for at least 2 weeks prior to enrollment. Patients must be off
(immunosuppressive doses of) corticosteroid therapy

3. Expansion cohort(s) only: Patients with tumors tested positive for epidermal growth
factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) gene mutations or ROS1
fusions.

4. Radiation therapy within 2 weeks prior to enrollment and not recovered to baseline
from any AE due to radiation

5. Patients who received prior treatment with an anti-cytotoxic T-lymphocyte-associated
protein 4 (CTLA-4) antibody

6. Previous treatment with idelalisib (ZYDELIG®) at any time

Note: Other protocol defined inclusion/ exclusion criteria apply