A Study to Assess the Potential Effects of Rifampin on the Pharmacokinetics of Trabectedin in Patients With Advanced Malignancies

This is an open-label study (patients will know the names of the study drugs they receive),
randomized (patients will be assigned 1 of 2 treatment sequences by chance) that is designed
to examine the pharmacokinetics (blood levels) and to assess survival and safety of
trabectedin when coadministered with rifampin in patients with advanced malignancies. Study
drugs include trabectedin and rifampin. Trabectedin is a drug being developed to treat
patients with cancer that will be administered intravenously (i.v.) through a catheter
(tube) into a central vein over a period of 3 hours once every 28 days with and without
rifampin. Rifampin is an antibiotic that may interfere with the action of trabectedin that
will be taken orally (by mouth) as capsules. In addition, dexamethasone, a drug used to
prevent nausea and vomiting in chemotherapy patients that may have protective effects on the
liver, will be administered to patients before the administration of trabectedin. In the
study, 3 patients will initially be randomized sequentially to Treatment Sequence 1 or
Treatment Sequence 2 to evaluate safety. If the safety and pharmacokinetic data collected
from these 3 patients is deemed acceptable, additional patients will be randomized to 1 of 2
treatment sequences. Patients who complete the treatment phase of the study or who are
discontinued due to rifampin toxicity, and who in the opinion of the investigator would
derive an overall clinical benefit from further treatment with trabectedin, will have the
opportunity to continue treatment with trabectedin in the optional extension phase. The dose
and schedule of trabectedin may be modified by the treating physician in the optional
extension phase to be more appropriate for the type of malignancy being treated. Patients
will receive 20 mg of i.v. dexamethasone (or its equivalent) prior to trabectedin
administration in all cycles. Patients randomized to Sequence 1 will receive rifampin 600mg
1X daily(6 doses)+trabectedin 1.3 mg/m2 i.v. followed 28 days later by trabectedin 1.3 mg/m2
i.v. Patients randomized to Sequence 2 will receive trabectedin 1.3 mg/m2 i.v. followed 28
days later by rifampin 600mg 1X daily(6 doses)+trabectedin 1.3mg/m2 i.v. Dexamethasone 20
mg i.v., or equivalent will be administered 30 minutes prior to trabectedin administration.

Inclusion Criteria:

- Patients with locally advanced or metastatic disease, any solid tumor except
hepatocellular carcinoma, who have relapsed or had progressive disease following
standard of care treatment with chemotherapy prior to enrollment, or intolerant to
prior standard of care treatment with chemotherapy

- Patients with Eastern Cooperative Oncology Group (ECOG) score of <=2

- Patients able to receive dexamethasone

- Patients with hepatic function variables: total bilirubin <=upper limit of normal
(ULN), alkaline phosphatase (ALP) <=1.5 ULN and liver function test results (alanine
aminotransferase [ALT] and aspartate aminotransferase [AST]) of <=2.5x ULN

Exclusion Criteria:

- Patients with previous exposure to trabectedin

- Patients with cancer that has metastasized (spread) to the central nervous system

- Patients with known liver disease

- Patients who had a myocardial infarct (heart attack) within 6 months before
enrollment or who have any other clinically significant or unstable medical condition
as assessed by the Investigator

- Patients unable to have a central catheter