American Association for Cancer Research
cd-23-0964_supplementary_figure_s1_suppsf1.pdf (42.25 kB)

Supplementary Figure S1 from Xaluritamig, a STEAP1 × CD3 XmAb 2+1 Immune Therapy for Metastatic Castration-Resistant Prostate Cancer: Results from Dose Exploration in a First-in-Human Study

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posted on 2024-01-12, 08:21 authored by William K. Kelly, Daniel C. Danila, Chia-Chi Lin, Jae-Lyun Lee, Nobuaki Matsubara, Patrick J. Ward, Andrew J. Armstrong, David Pook, Miso Kim, Tanya B. Dorff, Stefanie Fischer, Yung-Chang Lin, Lisa G. Horvath, Christopher Sumey, Zhao Yang, Gabor Jurida, Kristen M. Smith, Jamie N. Connarn, Hweixian L. Penny, Julia Stieglmaier, Leonard J. Appleman

Supplementary Figure S1: Supplementary Figure S1 showing study schema for xaluritamig intravenous monotherapy dose exploration and expansion phases.


Amgen (Amgen Inc.)



Xaluritamig (AMG 509) is a six-transmembrane epithelial antigen of the prostate 1 (STEAP1)–targeted T-cell engager designed to facilitate lysis of STEAP1-expressing cancer cells, such as those in advanced prostate cancer. This first-in-human study reports monotherapy dose exploration for patients with metastatic castration-resistant prostate cancer (mCRPC), primarily taxane pretreated. Ninety-seven patients received ≥1 intravenous dose ranging from 0.001 to 2.0 mg weekly or every 2 weeks. MTD was identified as 1.5 mg i.v. weekly via a 3-step dose. The most common treatment-related adverse events were cytokine release syndrome (CRS; 72%), fatigue (45%), and myalgia (34%). CRS occurred primarily during cycle 1 and improved with premedication and step dosing. Prostate-specific antigen (PSA) and RECIST responses across cohorts were encouraging [49% PSA50; 24% objective response rate (ORR)], with greater frequency at target doses ≥0.75 mg (59% PSA50; 41% ORR). Xaluritamig is a novel immunotherapy for prostate cancer that has shown encouraging results supporting further development. Xaluritamig demonstrated encouraging responses (PSA and RECIST) compared with historical established treatments for patients with late-line mCRPC. This study provides proof of concept for T-cell engagers as a potential treatment for prostate cancer, validates STEAP1 as a target, and supports further clinical investigation of xaluritamig in prostate cancer.See related commentary by Hage Chehade et al., p. 20.See related article by Nolan-Stevaux et al., p. 90.This article is featured in Selected Articles from This Issue, p. 5

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