Inclusion Criteria:

- Adult patients with histologically-confirmed recurrent non-small cell lung cancer
have had at least two prior systemic treatment regimens

- Must have measurable disease according to RECIST

- Eastern Cooperative Oncology Group performance status 0-1

- Adequate bone marrow, hepatic and renal function

- Ability to swallow capsules

- At least 3 weeks from prior systemic treatments including investigational anti-cancer
therapy, at least 7 days from prior radiation therapy and have recovered from prior
toxicities

- At least 3 weeks from major surgery

Exclusion Criteria:

- Non-small cell cancer histology contains a component of small cell lung cancer

- Previously untreated CNS metastasis or progressive CNS metastasis

- Prior treatment with a CDK inhibitor

- Currently receiving radiotherapy, biological therapy, or any other investigational
therapy

- Uncontrolled intercurrent illness

- Having other cancers that have been treated with chemotherapy or biological therapy
in the past 5 years with the exception of adequately treated in situ cervical cancer
or basal cell skin cancer

- Pregnant or lactating women

- Known to be HIV-positive

- Active hepatitis B and/or hepatitis C infection