Inclusion Criteria:

- Adult patients, >/= 18 years of age

- Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1

- Histologically confirmed metastatic melanoma (AJCC stage IV) or unresectable melanoma
(AJCC Stage III)

- Prior failure of >/= 1 prior treatment regimens for metastatic or unresectable
melanoma due to disease progression or unacceptable toxicity and for whom no standard
therapy is available

- Measurable disease according to RECIST criteria

- Adequate bone marrow, liver and renal function

- Female patients of childbearing potential and male patients with female partners of
childbearing potential must agree to use one highly effective form of non-hormonal
contraception or two effective forms of non-hormonal contraception through the course
of the study treatment and for 6 months after the last dose of study treatment

Exclusion Criteria:

- Treatment with cytotoxic or antibody based therapy within 21 days prior to first dose
of study treatment, or with any other anti-cancer therapy within 5 half-lives of the
therapy prior to first dose of study treatment

- Known active infection (including HIV and atypical mycobacterial disease, but
excluding fungal infection of the nail beds)

- Current Grad >/= 2 toxicity (except alopecia or anorexia) from prior therapy

- Grade >/= 2 peripheral neuropathy

- History of severe allergic or anaphylactic reactions to monoclonal antibody therapies
(or recombinant antibody-related fusion proteins)

- Clinically significant history of liver disease, including viral or other hepatitis,
current alcohol abuse, or cirrhosis

- Untreated or active central nervous system (CNS) metastases (progressing or requiring
anticonvulsants or corticosteroids for symptomatic control)

- Evidence of significant uncontrolled concomitant disease or disorder

- Pregnant or lactating women

- Prior treatment with any other antibody-drug conjugate (ADC) compound containing
monomethyl auristatin E (MMAE) for the treatment of melanoma

- Previous participation in a clinical trial within 30 days of the day of first study
drug administration (Cycle 1, Day 1)