Conditions: Gastrointestinal Stromal Tumors
Keywords: Gastrointestinal stromal tumors DS-6157a Anti-drug antibody conjugate G-protein coupled receptor 20 (GPR20)
Allocation: NON_RANDOMIZED | Intervention model: SEQUENTIAL
Enrollment: 34
Healthy volunteers: no

Brief summary:
This study will assess the safety, efficacy, and pharmacokinetics of DS-6157a in participants with advanced gastrointestinal stromal tumors (GIST).

Detailed description:
This study is a two-part, multicenter, open-label, multiple-dose, first-in-human study of the antibody-drug conjugate (ADC) DS-6157a given as a single agent to participants with gastrointestinal stromal tumor (GIST).

This study will include 2 parts:

1. Dose Escalation (Part 1)
2. Dose Expansion (Part 2)

Dose Escalation: Participants with histopathologically documented advanced GIST not amenable to curative therapy may be included in which the maximum tolerated dose (MTD) and/or recommended dose for expansion (RDE) of DS-6157a monotherapy will be determined.

Dose Expansion: Once the RDE(s) is established for DS-6157a (Part 1), enrollment in Dose Expansion (Part 2) will commence in 2 cohorts. Participants with GIST who have progressed on or are intolerant to imatinib (IM) and at least one post-IM treatment will be enrolled in Cohort 1, and participants with GIST who progressed on IM and had not received a post-IM treatment (2nd line) will be enrolled in Cohort 2.

The study was terminated after Dose Escalation and the study never proceeded to the Dose Expansion part.

Arms:
arm 1: Participants with advanced gastrointestinal stromal tumor (GIST) who will receive an intravenous infusion of DS-6157a (escalating doses starting at 1.6 mg/kg). arm 2: Participants with advanced gastrointestinal stromal tumor (GIST) who have progressed on or are intolerant to imatinib (IM) and at least one post-IM treatment will receive DS-6157a at the recommended dose for expansion (RDE) based on the Dose Escalation phase. arm 3: Participants with advanced gastrointestinal stromal tumor (GIST) who have progressed on imatinib (IM) and had not received a post-IM treatment (2nd line) will receive DS-6157a at the recommended dose for expansion (RDE) based on the Dose Escalation phase.

Interventions: intervention 1: DS-6157a
Intervention descriptions: intervention 1: Administered as a single agent intravenously (IV) every 3 weeks

Protocol document:
Prot_SAP_000.pdf: