TY - JOUR
T1 - Phase II Study of Samotolisib in Children and Young Adults With Tumors Harboring Phosphoinositide 3-Kinase/Mammalian Target of Rapamycin Pathway Alterations
T2 - Pediatric MATCH APEC1621D
AU - Laetsch, Theodore W.
AU - Ludwig, Kathleen
AU - Williams, P. Mickey
AU - Roy-Chowdhuri, Sinchita
AU - Patton, David R.
AU - Coffey, Brent
AU - Reid, Joel M.
AU - Piao, Jin
AU - Saguilig, Lauren
AU - Alonzo, Todd A.
AU - Berg, Stacey L.
AU - Mhlanga, Joyce
AU - Fox, Elizabeth
AU - Weigel, Brenda J.
AU - Hawkins, Douglas S.
AU - Mooney, Margaret M.
AU - Takebe, Naoko
AU - Tricoli, James V.
AU - Janeway, Katherine A.
AU - Seibel, Nita L.
AU - Parsons, Donald Williams
N1 - Publisher Copyright:
© American Society of Clinical Oncology.
PY - 2024/9/1
Y1 - 2024/9/1
N2 - PURPOSEPatients age 1-21 years with relapsed or refractory solid and CNS tumors were assigned to phase II studies of molecularly targeted therapies on the National Cancer Institute-Children's Oncology Group (NCI-COG) Pediatric Molecular Analysis for Therapy Choice (MATCH) trial. Patients whose tumors harbored predefined genetic alterations in the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway and lacked mitogen-activated protein kinase pathway activating alterations were treated with the PI3K/mTOR inhibitor samotolisib.METHODSPatients received samotolisib twice daily in 28-day cycles until disease progression or unacceptable toxicity. A rolling 6 limited dose escalation was performed as, to our knowledge, this was the first pediatric study of samotolisib. The primary end point was the objective response rate; secondary end points included progression-free survival (PFS) and the recommended phase II dose and toxicity of samotolisib in children.RESULTSA total of 3.4% (41/1,206) of centrally tested patients were matched to this arm. Seventeen patients were treated. Among treated patients, the most common diagnoses included osteosarcoma (n = 6) and high-grade glioma (n = 5) harboring alterations in phosphatase and tensin homolog (n = 6), PIK3CA (n = 5), and tuberous sclerosis complex 2 (n = 3). No objective responses or prolonged stable disease were observed. Three-month PFS was 12% (95% CI, 2 to 31). Two patients experienced dose-limiting toxicities (mucositis and pneumonitis). Dose level 2 (115 mg/m2/dose twice daily) was determined to be the recommended phase II dose of samotolisib in children.CONCLUSIONThis nationwide study was successful at identifying patients and evaluating the efficacy of molecularly targeted therapy for rare molecular subgroups of patients in a histology-agnostic fashion. Unfortunately, there was no activity of samotolisib against tumors with PI3K/mTOR pathway alterations. Prospective trials such as the NCI-COG Pediatric MATCH are necessary to evaluate the efficacy of molecularly targeted therapies given their increasing use in clinical practice.
AB - PURPOSEPatients age 1-21 years with relapsed or refractory solid and CNS tumors were assigned to phase II studies of molecularly targeted therapies on the National Cancer Institute-Children's Oncology Group (NCI-COG) Pediatric Molecular Analysis for Therapy Choice (MATCH) trial. Patients whose tumors harbored predefined genetic alterations in the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway and lacked mitogen-activated protein kinase pathway activating alterations were treated with the PI3K/mTOR inhibitor samotolisib.METHODSPatients received samotolisib twice daily in 28-day cycles until disease progression or unacceptable toxicity. A rolling 6 limited dose escalation was performed as, to our knowledge, this was the first pediatric study of samotolisib. The primary end point was the objective response rate; secondary end points included progression-free survival (PFS) and the recommended phase II dose and toxicity of samotolisib in children.RESULTSA total of 3.4% (41/1,206) of centrally tested patients were matched to this arm. Seventeen patients were treated. Among treated patients, the most common diagnoses included osteosarcoma (n = 6) and high-grade glioma (n = 5) harboring alterations in phosphatase and tensin homolog (n = 6), PIK3CA (n = 5), and tuberous sclerosis complex 2 (n = 3). No objective responses or prolonged stable disease were observed. Three-month PFS was 12% (95% CI, 2 to 31). Two patients experienced dose-limiting toxicities (mucositis and pneumonitis). Dose level 2 (115 mg/m2/dose twice daily) was determined to be the recommended phase II dose of samotolisib in children.CONCLUSIONThis nationwide study was successful at identifying patients and evaluating the efficacy of molecularly targeted therapy for rare molecular subgroups of patients in a histology-agnostic fashion. Unfortunately, there was no activity of samotolisib against tumors with PI3K/mTOR pathway alterations. Prospective trials such as the NCI-COG Pediatric MATCH are necessary to evaluate the efficacy of molecularly targeted therapies given their increasing use in clinical practice.
UR - http://www.scopus.com/inward/record.url?scp=85205923671&partnerID=8YFLogxK
U2 - 10.1200/PO.24.00258
DO - 10.1200/PO.24.00258
M3 - Article
C2 - 39298693
AN - SCOPUS:85205923671
SN - 2473-4284
VL - 8
JO - JCO Precision Oncology
JF - JCO Precision Oncology
M1 - e00258
ER -