A Phase I Dose-Escalation Study of IMGN388 in Patients With Solid Tumors

Inclusion Criteria:

- Male or female age greater than 18 years

- Signed informed consent(s): Patients must provide informed consent for study
participation prior to performing any study-specific procedures

- Histologically confirmed solid tumor that is metastatic or unresectable and for which
standard curative or palliative measures do not exist or are no longer effective

- Specifically for the dose expansion phase, enrollment will be limited to patients
with αv integrin positive melanomas or carcinomas of breast, lung, or ovary. Patients
must also have confirmation of αv integrin expression performed prior to enrollment
by immunohistochemical assessment for αv integrin on archived or if not available,
freshly collected tumor biopsy samples. αv integrin positive tumors are defined as
having a staining intensity of at least 2+ and a staining uniformity of heterogeneous
(25 - 75% of tumor cells stain positively for αv integrin) or homogeneous staining
(>75% of tumor cells are positive for αv integrin) of tumor cells when evaluated by
immunohistochemistry .

- Evidence of measurable or evaluable metastatic disease at baseline

- Eastern Cooperative Oncology Group (ECOG) Performance Status score of less than or
equal to 2

- Adequate bone marrow, liver, and renal function at the time of first dose of study
agent, as described below:

- Hemoglobin greater than or equal to 9.0 g/dL (5.6 mmol/L; 90 g/L) without transfusion
dependency

- Absolute neutrophil count (ANC)greater than or equal to 1.5 x 109/L (1500/mm3)
without hematopoietic cytokine support

- Platelets greater than or equal to 100,000 x 109/L (100,000/mm3) without transfusion
dependency

- Coagulation [prothrombin time (PT) or international normalized ratio (INR) and
activated partial prothrombin time (aPTT)] ≤ 1.25 x upper limit of normal (ULN)

- Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 x ULN if no
liver metastasis; ≤ 5 x ULN if liver metastasis

- Total Bilirubin ≤ 1.5 x ULN

- Serum creatinine ≤ 1.5 x ULN

- Female patients must be postmenopausal (at least 12 months since last menses),
surgically sterile, abstinent, or, if sexually active, be practicing an effective
method of birth control (e.g., prescription oral contraceptives, contraceptive
injections, intrauterine device, double-barrier method, contraceptive patch, male
partner sterilization) before study entry, for the duration of study participation,
and for three months after the last infusion of study agent and must have a negative
urine or serum pregnancy test within 1 week before beginning treatment on this study
and at all specified timepoints throughout the study. Men must be sterilized or agree
to use a double-barrier method of birth control and must agree to not donate sperm
during the study and for three months after the last infusion of study agent.

- Able to adhere to study visit schedule and all protocol requirements

- The anticipated life expectancy is such that the patient is expected to be able to
participate for the duration of the study

Exclusion Criteria:

Patients meeting any of the following criteria may not be enrolled in the study:

- Residual toxicities resulting from previous therapy that are ≥ Grade 1

- Neuropathy of > Grade 1

- History of uveitis within 6 months of first dose of study agent or presenting with
uveitis at baseline

- Concomitant or prior malignancy (other than the one under study) except adequately
treated basal cell or squamous cell carcinoma of the skin or carcinoma in situ of the
cervix

- Patients with solid tumors with history of active bleeding

- Treatment with systemic cancer therapy, radiotherapy or any investigational agent
within 4 weeks or five half-lives (whichever is longer) of first dose of study agent

- Known allergies or clinically important reactions to human proteins or to therapeutic
antibodies

- Major surgery within 4 weeks of first dose of study agent, or planning to have
surgery (except for minor surgical procedures) during the study, or planned major
surgery within 8 weeks after the last dose of study agent

- Serious concurrent illness (medical or psychiatric), altered mental status (e.g.,
dementia) or any uncontrolled medical condition (eg, uncontrolled diabetes),
including the presence of laboratory abnormalities, that would place the patient at
unacceptable risk by participating in the study or would confound the ability to
interpret data from the study

- Uncontrolled infection, clinically important active infection within 4 weeks before
the first dose of study agent, or currently receiving treatment for an infection

- Active angina pectoris or New York Heart Association (NYHA) Class III or IV heart
disease. Cardiac disease characterized by significant ischemic coronary disease,
significant arrhythmias, or congestive heart failure (greater than NYHA Class II) or
myocardial infraction within the past 6 months

- Known or symptomatic central nervous system (CNS) metastases

- Known to be seropositive for human immunodeficiency virus (HIV), or active Hepatitis
A, B, or C infection

- Any other concomitant anti-cancer treatment such as immunotherapy, biotherapy,
radiotherapy, chemotherapy, investigative therapy, or high-dose steroids; however,
low-dose steroids and Luteinizing Hormone Releasing Hormone (LHRH) at doses that have
been stable for ≥ 14 days are permitted for patients with prostate cancer

- Any medical condition that, in the opinion of the investigator, may compromise the
safety of the patient or their ability to receive study treatment

- Pregnant or lactating women

Patients will continue to be followed for short term follow-up and long term survival.