Pembrolizumab With or Without Talimogene Laherparepvec or Talimogene Laherparepvec Placebo in Unresected Melanoma (KEYNOTE-034)

Key Inclusion Criteria:

- Age ≥ 18 years with histologically confirmed diagnosis of melanoma and stage IIIB to
IVM1c for whom surgery is not recommended.

- Subjects must have measurable disease and be a candidate for intralesional therapy
administration into cutaneous, subcutaneous, or nodal lesions.

- ECOG performance status of 0 or 1.

- Adequate hematologic, hepatic, renal, and coagulation function.

- Subjects with BRAFV600 wild-type tumors must not have received any prior systemic
anticancer treatment consisting of chemotherapy, immunotherapy, or targeted therapy
given in a non-adjuvant setting for unresectable stage IIIB to IVM1c melanoma.

- Subjects with B-Raf V600 (BRAFV600) mutated tumors who have received prior BRAF
inhibitor therapy either alone or in combination with MEK inhibitor as their only
prior systemic therapy are eligible.

- Subjects who received prior adjuvant therapy for melanoma will not be excluded
(including, but not limited to, interferon, ipilimumab, limb infusion/perfusion, or
use of investigational agents in the adjuvant setting) with the exception that prior
adjuvant therapy with inhibitors of programmed cell death 1 (PD-1) or programmed cell
death ligand 1 (PD-L1) is not allowed. However, if the subject received adjuvant
therapy, the subject must have completed therapy at least 28 days prior to enrollment.

- Subjects must have a tumor sample that is adequate for PD-L1 assessment prior to
randomization.

Key Exclusion Criteria:

- Subjects must not have clinically active cerebral metastases.

- Subjects must not have primary uveal or mucosal melanoma, history or evidence of
melanoma associated with immunodeficiency states or history of other malignancy within
the past 3 years.

- Subjects may not have been previously treated with talimogene laherparepvec, any other
oncolytic virus, pembrolizumab, or any other inhibitor of PD-1, PD-L1, or PD-L2.

- Subjects must not have history or evidence of symptomatic autoimmune pneumonitis,
glomerulonephritis, vasculitis, other symptomatic autoimmune disease, documented
history of autoimmune disease or syndrome requiring systemic treatment in the past 2
years (ie, with use of disease modifying agents, steroids or immunosuppressive agents)
except vitiligo or resolved childhood asthma/atopy, or evidence of clinically
significant immunosuppression.

- Subjects must not have active herpetic skin lesions or prior complications of herpetic
infection and must not require intermittent or chronic treatment with an antiherpetic
drug (eg, acyclovir), other than intermittent topical use.