A Phase I/II, Open-Label, Multicenter Study of Single Agent PT-523 in the Treatment of Relapsed or Refractory Non-Small Cell Lung Cancer (NSCLC)

Inclusion Criteria:

- Age ≥ 18 years

- Histologically or cytologically confirmed NSCLC which is stage III or stage IV, or
recurrent disease, and failed therapy with a standard first line (Phase I/II) as well
as second line chemotherapy regimen (Phase I), or be intolerant of standard
chemotherapy. Receipt of one additional prior chemotherapy regimen for neoadjuvant,
adjuvant, or neoadjuvant plus adjuvant is allowable. A prior epidermal growth factor
receptor tyrosine kinase inhibitor (EGFR-TK) antagonist is allowable (Phase II).

- Asymptomatic or treated brain metastases (including steroids) if last therapy was
received > 4 weeks from study entry and is deemed by the investigator to have a low
likelihood of rapid deterioration.

- ECOG performance status 0 - 2.

- Adequate organ function and bone marrow reserve.

- Use of appropriate contraceptive method.

- Signed patient informed consent.

Exclusion Criteria:

- Investigational agents within 30 days prior to Day 1 of study.

- Known symptomatic or uncontrolled brain metastases.

- Uncontrolled intercurrent illness.

- Known human immunodeficiency virus (HIV), hepatitis A, B, C, D and E.

- Patient has uncontrolled pleural effusions.

- Patient has received nitrosoureas or mitomycin-C within 6 weeks or other chemotherapy
or radiation therapy within 3 weeks before study entry.