Rollover Protocol for Subjects Who Have Responded on Study 4218s - A Phase 2 Study

Rollover for Study OX4218s, A P2 Study to Investigate Safety and Activity of Fosbretabulin Tromethamine in the Treatment of Well-Differentiated, Low-to-Intermediate-Grade Unresectable, Recurrent or Metastatic PNET or GI-NET With Elevated Biomarkers

Subjects achieving a clinical response in study OX4218s with a biomarker reduction or symptom response are eligible to enroll in this rollover study to continue once every three weeks fosbretabulin infusions for up to one year.

Subjects enrolled in the PNET/GI-NET study OX4218s received weekly dosing with fosbretabulin for up to 3 cycles or approximately 9 weeks. Subjects achieving a clinical response with a biomarker reduction or symptom response based on investigator assessment are eligible to enroll in this rollover study (protocol OX4219s). Subjects will receive fosbretabulin every three weeks for a maximum of approximately one year or until disease progression, unacceptable toxicity, consent withdrawal, protocol-noncompliance, or the investigator feels that it is no longer in the subject's best interest to continue therapy.

Inclusion Criteria:

• Subject has been treated in the OXiGENE-sponsored Phase 2 study OX4218s

Exclusion Criteria:

• Subject has not received fosbretabulin treatment in the study OX4218s