Selpercatinib Pre-RAI in Patients With RET Fusion Thyroid Cancer (RAISE)

The film gives the main points. The full list below is copied from the registry; the study team makes the final decision.

• Age2 Years to 25 Years
• SexAll
• Healthy volunteersNo

You may be able to join if

• Age 2-25 years, inclusive
• Histologic diagnosis of a differentiated thyroid cancer, status post thyroidectomy and adequate local therapy (e.g., lymph node dissection as per standard of care) for metastatic disease in the neck in the opinion of the treating investigator
• Anatomically evaluable disease on chest CT (Computed Tomography) meeting one of the following criteria (obtained within 90 days of enrollment):
• A. multiple (> 10) noncalcified solid pulmonary nodules visible on CT and/or B. enlarging, discrete pulmonary nodules visible on CT of any number consistent with metastatic disease
• Identification of an activating RET gene alteration (fusion or mutation). The RET alteration result should be generated from a laboratory with specific certifications (depending on country requirement) that clearly denotes the presence of a RET alteration without known kinase domain resistance mutation
• Lansky/Karnofsky performance status >50%
• Adequate Organ Function
• A. Bone Marrow Function:
• Peripheral absolute neutrophil count (ANC) ≥1500/µL
• Platelet count ≥ 100,000/µL (transfusion independent, defined as not receiving platelet transfusions for at least 7 days prior to enrollment)
• Hemoglobin ≥ 9.0 g/dL at baseline (may receive Red Blood Cell transfusions).
• B. Adequate Renal Function: Creatinine clearance or radioisotope Glomerular Filtration Rate (GFR) ≥ 70 mL/min/1.73 m2 or a maximum serum creatinine based on age/gender.
• C. Adequate Liver Function
• Bilirubin (sum of conjugated + unconjugated) < / = 1.5 x upper limit of normal (ULN) for age. Except participants with a documented history of Gilbert syndrome who must have a total bilirubin level of <3.0X ULN
• Alanine aminotransferase (ALT) <2.5X ULN OR <5x ULN if the liver has tumor involvement. For the purpose of this study, the ULN for ALT is 45 U/L.
• Serum albumin ≥ 2 g/dL
• Patient must have normal serum potassium, calcium, and magnesium levels (may be receiving supplements)
• Men with partners of childbearing potential or women of childbearing potential must agree to use a highly effective contraceptive method during treatment with study drug and for 6 months following the last dose of study drug. Selpercatinib could impair fertility in males and females. Advise women not to breastfeed during treatment with selpercatinib and for 1 week following the final dose
• Women of childbearing potential must have a negative pregnancy test (serum or urine, consistent with local regulations) documented within 24 hours prior to treatment with study drug and at least monthly while on study treatment

You cannot join if

• No prior systemic therapy for thyroid cancer, including RET inhibitors. Note: prior 131I is allowed.
• Females who are pregnant or breastfeeding are excluded due to the potential risks of selpercatinib and radioactive iodine to the fetus/neonate.
• Concurrent therapy: Patients currently receiving a strong CYP3A4 inducer or inhibitor are not eligible. Strong inducers or inhibitors of CYP3A4 should be avoided 14 days prior to treatment to the end of the study treatment.
• Patients with clinically significant active cardiovascular disease, Torsades de pointes, or history of myocardial infarction within 6 months prior to planned start of study treatment or prolongation of the QT interval corrected for heart rate using Fridericia's formula (QTcF) >470 msec.
• Have clinically significant active malabsorption syndrome or other condition likely to affect gastrointestinal absorption of the drug.
• Are taking a concomitant medication that is known to cause QTc prolongation.
• Active hemorrhage or at significant risk for hemorrhage.
• Uncontrolled hypertension (blood pressure greater than 140/90 in adults or greater than the 95% for height and gender in children). Use of anti-hypertensives to control blood pressure is permitted.

This is how the treatment is meant to work. Whether it helps, and how safe it is, is what this trial is testing.

selpercatinib. An orally bioavailable selective inhibitor of wild-type, mutant and fusion products involving the proto-oncogene receptor tyrosine kinase rearranged during transfection (RET), with potential antineoplastic activity. Upon oral administration, selpercatinib selectively binds to and targets wild-type RET as well as various RET mutants and RET-containing fusion products. This results in an inhibition of cell growth of tumors cells that exhibit increased RET activity. In addition, selpercatinib targets, binds to and inhibits vascular endothelial growth factor receptor 1 (VEGFR1) and 3 (VEGFR3), and fibroblast growth factor receptor 1 (FGFR1), 2 (FGFR2), and 3 (FGFR3). RET overexpression, activating mutations, and fusions result in the upregulation and/or overactivation of RET tyrosine kinase activity in various cancer cell types; dysregulation of RET activity plays a key role in the development and progression of these cancers. NCI Drug Dictionary

Treatments listed in the registry

• Selpercatinib Monotherapy (Drug): Patients will receive selpercatinib monotherapy for 6 months at the FDA-approved dose.
• 131I Therapy (Radiation): Patients will receive 131I therapy after 6 months of selpercatinib.

Na · Single Group · masking: None

Main goals

• Number of patients with complete overall, pulmonary, structural, and biochemical response. (18 months)
• Number of patients who survive without progression of disease after 5 years following protocol treatment. (5 years)
• Proportion of all patients enrolled who show increased radioactive iodine avidity at 6 months following selpercatinib monotherapy. (6 months)
• The incidence of adverse events and dose limiting toxicity with the combination of selpercatinib and 131I therapy, graded according to CTCAE v5. (12 months)

Planned enrollment: 13 (estimated).

• Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
• St. Jude Children's Research Hospital, Memphis, Tennessee
• MD Anderson Cancer Center, Houston, Texas

Site status as of Oct 30, 2026. Check the live record before contacting a site.

• ClinicalTrials.gov NCT06458036
• NCI Drug Dictionary: C134987

Registry record reviewed as fetched Oct 30, 2026, last updated by the sponsor Jul 23, 2026. Public record; not medical advice.