Palliative Radiotherapy With Lurbinectedin in Patients With Extensive Stage Small Cell Lung Cancer

Inclusion Criteria:

• Age >= 18 years

• Eastern Cooperative Oncology Group (ECOG) performance status =< 3

• Patients with pathologically confirmed ES-SCLC who are receiving lurbinectedin orare candidates for lurbinectedin therapy after progression on first-line systemictherapy (either chemotherapy [platinum etoposide] or chemoimmunotherapy) at thediscretion of the treating medical oncologist.

• Metastatic bone or visceral/lung metastatic disease as assessed computed tomography (CT), magnetic resonance imaging (MRI), bone scan or positron emission tomography (PET)/CT within 90 days prior to RT on this study.

• Patients with treated brain metastases are eligible but must require < 10 mg ofdexamethasone daily or its glucocorticoid equivalent. Brain metastases will not betreated in the context of this protocol.

• Absolute neutrophil count (ANC) >= 1,500/cells/mm^3

• Platelets >= 100,000/cells/mm^3

• Hemoglobin > 7.0 g/dL

• Total Bilirubin ≤ 1.5 ULN

• Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) =< 3.0 x ULN (=< 5.0x ULN for liver involvement)

• Alkaline phosphatase =< 2.5x ULN (=< 5.0x with documented liver or bone metastases)

• Based on its mechanism of action, lurbinectedin could cause harm when administeredto a pregnant woman. Taken together with the known teratogenicity of RT, female ofchild-bearing potential (FCBP) must have a negative serum or urine pregnancy testprior to starting protocol therapy. A female of childbearing potential (FCBP) is asexually mature woman who: 1) has not undergone a hysterectomy or bilateraloophorectomy; or 2) has not been naturally postmenopausal for at least 24consecutive months (i.e., has had menses at any time in the preceding 24 consecutivemonths.

• FCBP and men must agree to use adequate contraception (hormonal or barrier method ofbirth control; abstinence) prior to study entry and for the duration of studyparticipation and 6 months after the final dose of lurbinectedin. Should a womanbecome pregnant or suspect she is pregnant while she or her partner is participatingin this study, she should inform her treating physician immediately. Men treated orenrolled on this protocol must also agree to use adequate contraception prior to thestudy, for the duration of study participation, and 4 months after completion oflurbinectedin administration. FCBP who are currently breastfeeding must discontinueduring and up to 2 weeks after the final dose of lurbinectedin.

• Completion of all previous cancer-directed therapies (excluding lurbinectedin) forthe treatment of cancer >= 3 weeks before the start of study therapy.

• Willingness and ability of the subject to comply with scheduled visits, drugadministration plan, protocol-specified laboratory tests, other study procedures,and study restrictions.

• Evidence of a personally signed informed consent indicating that the subject isaware of the neoplastic nature of the disease and has been informed of theprocedures to be followed, the experimental nature of the therapy, alternatives,potential risks and discomforts, potential benefits, and other pertinent aspects ofstudy participation.

Exclusion Criteria:

An individual who meets any of the following criteria will be excluded from participation in this study:

• Pregnancy or breastfeeding within 2 weeks

• Patients may not enroll in both safety cohorts

• Patients who have received prior RT will be permitted to enroll. However, themetastases treated on this study must be > 2 cm from the following previouslyirradiated structures:

• Spinal cord previously irradiated to > 40 Gy (delivered in =< 3Gy/fraction)

• Brachial plexus previously irradiated to > 50Gy (delivered in =< 3Gy/fraction)

• Small intestine, large intestine, or stomach previously irradiated to > 45Gy (delivered in =< 3Gy/fraction)

• Brainstem previously irradiated to > 50Gy (delivered in =< 3Gy/fraction)

• Lungs previously irradiated with prior V20Gy > 35 percent (delivered in =< 3Gy/fraction)