Dr. Halperin on the Efficacy of the Protocol PEN-221-001 Study in Advanced GI NETs

Daniel M. Halperin, MD, associate professor, Department of Gastrointestinal (GI) Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, discusses the efficacy and safety results of the phase 1/2a Protocol PEN-221-001 trial (NCT02936323) in advanced gastrointestinal (GI) mid-gut neuroendocrine tumors (NETs).

The Protocol PEN-221-001 trial evaluated PEN-221, an intravenous somatostatin analog (SSA)-DM1 conjugate, in patients with advanced or metastatic, well-differentiated, low or intermediate grade, GI mid-gut NETs. The primary end point of the study was the clinical benefit rate (CBR), Halperin says. 

The results of the study, which were presented during the 2021 NANETS Symposium, demonstrated a CBR of 88.5% with PEN-221, which exceeded the investigators previous expectations, Halperin adds. 

PEN-221 was tolerated relatively well in patients; however, pharmacokinetic and pharmacodynamic findings confirmed that PEN-221 was best dosed based on body surface area, Halperin says. This helped increase the tolerability of the agent, Halperin concludes.