Efficacy Study of Pharmacokinetic(PK)/Pharmacodynamic(PD) Relationship of Monotherapy MORAb-004 in Metastatic Melanoma

Inclusion Criteria:

* Be surgically sterile or consent to use a medically acceptable method of contraception throughout the study period.
* Histologically confirmed diagnosis of metastatic melanoma
* At least 1 prior systemic treatment for metastatic melanoma with disease progression following treatment
* Measurable disease, as defined by RECIST v1.1, assessed within 4 weeks prior to study entry
* At least 3 week interval between first infusion of test article and most recent prior systemic anticancer therapy. All treatment-associated toxicity must be resolved to less than or equal to Grade 1 before the administration of MORAb-004
* Have a life expectancy of at least 3 months as estimated by the investigator
* Have other significant medical conditions well-controlled and stable, in the opinion of the investigator, for at least 30 days prior to Study Day 1
* Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
* Have sites of disease amenable to the protocol-specified biopsy (Note: All participants will have protocol-specified biopsy at Screening. The second, on-treatment biopsy will be mandatory in the first 30 randomized participants only. For all other participants, the second biopsy is optional.
* Laboratory tests results prior to Study Day 1 within limits as outlined in protocol

Exclusion Criteria:

* Have received no prior systemic treatment for metastatic melanoma
* Evidence of other active malignancy requiring treatment within the last 5 years (other than basal cell or squamous cell carcinoma of the skin), or active brain metastasis
* Clinically significant heart disease (Congestive heart failure of New York Heart Association \[NYHA\] Class 3 or 4, angina not well controlled by medication, or myocardial infarction within 6 mos.), or ECGs demonstrating clinically significant arrhythmias
* Have any other serious systemic disease, including active bacterial or fungal infection, or any medical condition requiring cytotoxic therapy or chronic (at least 4 consecutive weeks) systemic corticosteroid use
* Have active viral hepatitis or symptomatic Human immunodeficiency virus (HIV) infection
* Be breast-feeding, pregnant, or likely to become pregnant during the study
* Known allergic reaction to a prior monoclonal antibody therapy
* Previous treatment with MORAb-004
* Brain metastasis