Safety and Activity Study of PSCA-Targeted CAR-T Cells (BPX-601) in Subjects With Selected Advanced Solid Tumors

Bellicum Pharmaceuticals

Status and phase: Suspended; Phase 2; Phase 1

Conditions: Metastatic Prostate Cancer; Metastatic Castration-resistant Prostate Cancer

Treatments: Drug: Rimiducid; Biological: BPX-601

Study type: Interventional

Funder types: Industry

Identifiers

NCT02744287

BP-012

Details and patient eligibility

About

The purpose of this study is to evaluate the safety and activity of BPX-601 CAR-T cells in participants with previously treated advanced solid tumors (prostate) expressing high levels of prostate stem cell antigen (PSCA). Participants' T cells are modified to recognize and target the PSCA tumor marker on cancer cells.

Full description

The goal of this study is to characterize the feasibility, safety, and clinical activity of PSCA-specific CAR-T cells, BPX-601, administered with rimiducid to subjects with previously treated, PSCA-positive advanced solid tumors (prostate). BPX-601 CAR-T cells are genetically engineered to express a chimeric antigen receptor (CAR) to target the PSCA antigen and a rimiducid-inducible signaling domain which functions as a molecular "go-switch" to enhance activation and proliferation.

Phase 1: Cell dose escalation to identify the maximum dose of BPX-601 administered with single or repeat doses of rimiducid.

Phase 2: Indication-specific dose expansion to assess the safety, pharmacodynamics (including BPX-601 persistence), and clinical activity at the recommended dose identified in Phase 1 in various PSCA-expressing solid tumors.

Enrollment: 151 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Metastatic castration-resistant prostate cancer (mCRPC), with progressive disease per PCWG3 criteria during or following the direct prior line of therapy.
• Measurable disease per RECIST v1.1 at baseline; subjects with mCRPC with bone only metastases must have measurable PSA.
• Age ≥18 years.
• Life expectancy > 12 weeks.
• ECOG 0-1
• Adequate organ function.

Exclusion criteria

• Prostate cancer with unstable bone lesions or symptomatic/untreated coagulopathy, or history of > Grade 2 hematuria within the previous 6 months.
• Prior CAR T cell or other genetically-modified T cell therapy. Prior treatment with an immune-based therapy for the treatment of prostate cancer, including cancer vaccine therapies are allowable.
• Symptomatic, untreated, or actively progressing central nervous system metastases.
• Impaired cardiac function or clinically significant cardiac disease.
• Pregnant or breastfeeding.
• Participant requires chronic, systemic steroid therapy.
• Severe intercurrent infection.
• Known HIV positivity.

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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151 participants in 2 patient groups

Arm 1: Phase 1 Dose Escalation

Experimental group

Description:

Participants with advanced prostate cancer will receive an intravenous infusion of BPX-601 followed by one or more intravenous infusions of rimiducid. Dose escalation of BPX-601 will continue until the recommended cell dose level is reached.

Treatment:

Drug: Rimiducid

Biological: BPX-601

Arm 2: Phase 2 Dose Expansion

Experimental group

Description:

Participants with advanced prostate cancer will receive an intravenous infusion of BPX-601 at the recommended cell dose level followed by one or more intravenous infusions of rimiducid.

Treatment:

Drug: Rimiducid

Biological: BPX-601