A Study Evaluating STA-9090 in Patients With Metastatic and/or Unresectable Gastrointestinal Stromal Tumor (GIST)

Planned:

- Stage 1: 23 patients. If ≥4 patients had clinical benefit, an additional 32 patients
were to be enrolled. Up to 3 additional patients with platelet-derived growth factor
receptor, alpha polypeptide (PDGFRA) mutation were to be enrolled, regardless of the
total study enrollment.

- Stage 2: 55 patients. Progressing to this stage was dependent on Stage 1 results.

Analyzed:

- Stage 1: 27 patients were enrolled and analyzed. The study was not expanded to Stage 2
due to insufficient efficacy.

Inclusion Criteria:

- Must be at least 18 years of age at the time of study entry

- Must have histologically confirmed metastatic and/or unresectable GIST

- Must have measurable disease on computed tomography or magnetic resonance imaging as
defined by Response Evaluation Criteria in Solid Tumors (RECIST)

- Must have documented failure (due to either progression or intolerance)of at least
prior imatinib and sunitinib. Previous administration of other known heat shock
protein 90 (Hsp90) inhibitors is permitted

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

- Must have acceptable laboratory values as defined in the protocol

Exclusion Criteria:

- Known central nervous system metastases

- Major surgery within 4 weeks prior to receiving STA-9090

- Use of any investigational agents within 2 weeks or 6 half-lives of the agent,
whichever is shorter prior to receiving STA-9090

- No treatment with chronic immunosuppressants

- Must have otherwise adequate health status as defined in the protocol

- Left ventricular ejection fraction (LVEF) < than or = 50% at baseline

- Baseline corrected QT interval (QTc) > 470 msec

- Pregnant or lactating females