Phase 1b/II Trial of Carfilzomib With Irinotecan in Irinotecan-Sensitive Malignancies (Phase Ib) and Small Cell Lung Cancer Patients (Phase II) Who Have Progressed on Prior Platinum-based Chemotherapy

• Patients must have histologically or cytologically-confirmed diagnosis of progressive or recurrent malignancy as follows:

• Phase II: extensive stage small cell lung cancer with progression or recurrence after exactly one platinum-containing regimen. Patients who progressed during or within one month of completing platinum-based chemotherapy will be excluded. Patients who received primary curative chemoradiation therapy for limited disease, but who recur within the primary tumor site, previously radiated field or with distant metastases are also allowed to participate. Patients who have clinical evidence of recurrent small cell lung cancer do not require a confirmatory biopsy to be eligible for this trial. Prior irinotecan is not allowed.

• Patients must have measurable disease per RECIST criteria 1.1 performed within 28 days prior to enrollment. All other required tests to assess non-measurable disease must be performed within 42 days prior to enrollment.

• Patients with known brain metastases are eligible only if he/she has been treated for brain metastasis, are asymptomatic after treatment, have a stable CT or MRI of the brain within 28 days of enrollment and are not receiving corticosteroid therapy to control symptoms from brain metastasis. Only a non-enzyme inducing anticonvulsant (e.g., Keppra) will be permitted for those patients requiring anticonvulsants. (Topical and/or inhaled steroids are allowed.)

• Patients may have received previous radiation therapy, but it must have been completed at least 21 days prior to enrollment and the patient should have recovered from all associated toxicities. Measurable or non-measurable disease must be present outside the previous radiation field or a new lesion inside the radiation port must be present.

• Patients may have received prior surgery provided that at least 28 days have elapsed since major surgery (thoracic or other major surgeries) and the patient has recovered from all associated toxicities. Patients must have disease outside of the previous surgical resection area or a new lesion must be present.

• Patients must have a serum creatinine ≤ the institutional upper limit of normal OR a creatinine clearance ≥ 60 cc/min, measured or calculated (Cockcroft-Gault formula), obtained within 14 days prior to registration.

• Patients must have adequate hepatic function as documented by a bilirubin ≤ 2 x the institutional upper limit of normal, an alkaline phosphatase ≤ 2 x the institutional upper limit of normal, and an Serum Glutamate Oxaloacetic Transaminase (SGOT) and Serum Glutamate Pyruvate Transaminase (SGPT) ≤ 2 x the institutional upper limit of normal all obtained within 14 days prior to enrollment.

• Patients must have an Absolute Neutrophil Count (ANC) ≥ 1,500/μl and a platelet count ≥ 100,000/μl obtained within 14 days prior to registration.

• Patients must be 18 years of age or older.

• Patients must have a Zubrod Performance Status as follows:

‣ Phase Ib: 0 or 1

⁃ Phase II: 0, 1 or 2

• Patients must not be pregnant or nursing. Women/men of reproductive potential must have agreed to use an effective contraceptive method (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation.

• Male subjects must agree to practice contraception.

• All patients must be informed of the investigational nature of this study and must sign and give written informed consent in accordance with institutional and federal guidelines.