LuX: Xaluritamig in Participants With Metastatic Castrate Resistant Prostate Cancer and Suboptimal Response to Lutetium 177 Vipivotide Tetraxetan
brief summary
This is a phase 2a, open label, single arm, multi-site study of xaluritamig in mCRPC patients following treatment with ≥1 ARPI, taxane chemotherapy (if eligible) and stable or partial PSA response following 2 cycles of lutetium 177 vipivotide tetraxetan. Participants will continue treatment until clinical or radiographic progression of disease, withdrawal, or toxicity requiring discontinuation of therapy. All participants will be evaluated for overall response per RECIST v1.1,8 radiographic progression free survival (rPFS) by Prostate Cancer Working Group 3 (PCWG3) criteria, and PSA response. Approximately 30 participants will be enrolled. There is no data on response with alternative treatments following lutetium 177 vipivotide tetraxetan against which to benchmark the response rate. This phase 2a study will serve as an exploratory pilot to determine if a larger phase 2b study is warranted in this setting.
detailed description
Primary Objective and Endpoints
To evaluate the efficacy of xaluritamig following lutetium 177 vipivotide tetraxetan in patients with mCRPC, using a composite endpoint defined as the proportion of participants who achieve either of the following:
* Partial or complete response up to 24 weeks by local investigator's assessment per RECIST v1.1 in participants with baseline measurable disease, with confirmation at least 4 weeks after the initial observation; OR * PSA90, defined as a decline of ≥ 90% from baseline PSA (for participants with a baseline PSA ≥ 2.0 ng/mL) up to 24 weeks, confirmed by a subsequent PSA value obtained ≥3 weeks later.
Secondary Objectives and Endpoints
To evaluate the safety and efficacy of xaluritamig following lutetium 177 vipivotide tetraxetan in patients with mCRPC as measured by:
* Radiographic PFS * Duration of response, per RECIST v1.1 * Time to PSA response (30%, 50%, 70%, and 90%) * Time to PSA progression * Changes in laboratory safety evaluations (complete blood count \[CBC\], comprehensive metabolic panel \[CMP\], lactate dehydrogenase \[LDH\]) * Treatment-emergent adverse events (TEAE) following treatment initiation. * Duration of PSA 50/90 response
Correlative/Exploratory/Tertiary Objectives The following tertiary objectives are included in this protocol for exploratory purposes. However, it is important to note that these objectives may not be pursued depending on resource availability, feasibility, or other considerations during the course of the trial.
* To perform quantitative analysis of peripheral immune profile and cytokine profiles. * To perform somatic genomic analysis and measure circulating tumor cells. * To conduct immune and molecular analyses and exploratory prostate cancer biomarker studies to associate with clinical outcomes.
official title
LuX: A Feasibility Study of Xaluritamig in Participants With Metastatic Castrate Resistant Prostate Cancer and Suboptimal Response to Lutetium 177 Vipivotide Tetraxetan