Combining talazoparib with low dose radiotherapy for extensive-stage small cell lung cancer

A Phase I Study of Talazoparib and Consolidative Thoracic Radiotherapy for Extensive Stage Small Cell Lung Cancer

Phase 1 Interventional University Health Network, Toronto · NCT04170946

This study is testing if combining a new drug called talazoparib with low dose radiation can help people with extensive-stage small cell lung cancer who have stable disease after chemotherapy.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment24 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity Health Network, Toronto Academic / other
Drugs / interventionschemotherapy, immunotherapy, radiation
Locations1 site (Toronto, Ontario)
Trial IDNCT04170946 on ClinicalTrials.gov

What this trial studies

This phase I clinical trial evaluates the safety and maximum tolerated dose of talazoparib when combined with low dose thoracic radiotherapy in patients with extensive-stage small cell lung cancer who have stable disease after standard chemotherapy. Patients will begin taking talazoparib orally on day 1 and will receive low dose radiotherapy starting on day 6-9, continuing for 10 fractions over two weeks. The study aims to monitor clinical outcomes such as locoregional recurrence, progression-free survival, and overall survival, as well as assess acute and chronic toxicities over a year.

Who should consider this trial

Good fit: Ideal candidates are patients with histologically confirmed extensive-stage small cell lung cancer who have completed standard chemotherapy without disease progression.

Not a fit: Patients with untreated brain metastases or those who have received prior thoracic radiotherapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could improve treatment outcomes for patients with extensive-stage small cell lung cancer.

How similar studies have performed: While combining targeted therapies with radiotherapy is a common approach, the specific combination of talazoparib and low dose thoracic radiotherapy in this context is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Histological documented diagnosis of SCLC confirmed by a UHN pathologist.
* Documented extensive disease
* Completion of induction chemotherapy, 4-6 cycles of a platinum agent and etoposide.
* No disease progression (i.e.SD or better response by RECIST 1.1) at the completion of chemotherapy.
* Eastern Cooperative Oncology Group (ECOG) performance status 0-2 (Karnosfsky Performance Score (KPS) ≥50; see Appendix B).
* Adequate organ and marrow function,
* Postmenopausal or evidence of non-childbearing status for women of childbearing potential negative urine or serum pregnancy test within 28 days of study treatment and confirmed prior to treatment on day 1.

Exclusion Criteria:

* Untreated brain metastases.
* Previous radiotherapy to thorax (prior breast RT is permitted).
* Patients receiving any systemic chemotherapy, radiotherapy or immunotherapy (except for standard of care treatments or palliative reasons) within 3 weeks prior to study treatment.
* Exposure to an investigational product within 30 days or 5 half-lives (whichever is longer) prior to start of the current study drug.
* Any previous treatment with PARP inhibitor, including talazoparib.
* Concomitant use of strong P-gp inhibitors
* Concomitant use of other known P-gp inhibitors, P-gp inducers, or BCRP inhibitors
* Persistent toxicities (\>Common Terminology Criteria for Adverse Event (CTCAE) grade 2) caused by previous cancer therapy, excluding alopecia.
* Patients with myelodysplastic syndrome/acute leukaemia or with features suggestive thereof.
* Major surgery within 2 weeks of study treatment initiation and patients must have recovered from any effects of any major surgery.
* Patients considered a poor medical risk due to a serious, uncontrolled medical disorder, non-malignant systemic disease or active/uncontrolled infection. Examples include, but are not limited to, uncontrolled ventricular arrhythmia, recent (within 3 months) myocardial infarction, uncontrolled major seizure disorder, unstable spinal cord compression, superior vena cava syndrome, extensive interstitial bilateral lung disease on High Resolution Computed Tomography (HRCT) scan or any psychiatric disorder that prohibits obtaining informed consent
* Patients unable to swallow orally administered medication and patients with gastrointestinal disorders likely to interfere with absorption of the study medication.
* Immunocompromised patients,
* Previous allogenic bone marrow transplant or double umbilical cord blood transplantation (dUCBT).
* Whole blood transfusions in the last 120 days prior to entry to the study
* Other malignancy within the last 5 years
* Patients with spinal cord compression

Where this trial is running

Toronto, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Lung CancerSmall-Cell Lung CancerTalazoparibThoracic RadiotherapyChemotherapy
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.