Inclusion Criteria:

- Histologically or cytologically confirmed lung cancer (Stage IIIb/IV nonsmall-cell
lung cancer or extensive stage small-cell lung cancer [SCLC])

- Measurable tumor lesion (as long as it is not located in a previously irradiated
area) as defined by modified World Health Organization criteria

- Eastern Cooperative Oncology Group performance status of ≤1 at study entry

- Accessible for treatment and follow-up

Exclusion Criteria:

- Brain metastases

- Malignant pleural effusion

- Autoimmune disease

- Motor neuropathy of autoimmune origin

- SCLC-related paraneoplastic syndromes

- Any concurrent malignancy other than nonmelanoma skin cancer; carcinoma in situ of
the cervix or breast; or prostate cancer treated with systemic therapy (participants
with a previous malignancy but without evidence of disease for 5 years were allowed
to enter the study)

- Prior systemic therapy for lung cancer. Prior radiation therapy or locoregional
surgeries performed later than at least 3 weeks prior to randomization date were
allowed.

- Grade 2 peripheral neuropathy (motor or sensory)

- Known HIV or hepatitis B or C infection

- Chronic use of immunosuppressants and/or systemic corticosteroids (used in the
management of cancer or noncancer-related illnesses). However, use of corticosteroids
was allowed if used as premedication for paclitaxel infusion or for treating
immune-related adverse events or adrenal insufficiencies.

- Inadequate hematologic function defined by an absolute neutrophil count <1,500/mm^3,
a platelet count <100,000/mm^3, or hemoglobin level <9 g/dL.

- Inadequate hepatic function defined by a total bilirubin level >2.0 times the upper
limit of normal (ULN), or ≥2.5 times the ULN if liver metastases are present,
aspartate aminotransferase and alanine aminotransferase levels ≥2.5 times the ULN or
≥5 times the ULN if liver metastases are present.

- Inadequate renal function defined by a serum creatinine level ≥2.5 times the ULN

- Inadequate creatinine clearance defined as less than 50 mL/min.