Dose Escalation and Expansion Study of FLX475 Monotherapy and in Combination With Pembrolizumab
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ClinicalTrials.gov Identifier: NCT03674567 |
Recruitment Status :
Recruiting
First Posted : September 17, 2018
Last Update Posted : June 14, 2022
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This clinical trial is a Phase 1/2, open-label, sequential-group, dose-escalation and cohort expansion study to determine the safety and preliminary anti-tumor activity of FLX475 as monotherapy and in combination with pembrolizumab.
The study will be conducted in 2 parts, a dose-escalation phase (Part 1) and a cohort expansion phase (Part 2). In Part 1 of the study, subjects will be enrolled in sequential cohorts treated with successively higher doses of FLX475 as monotherapy or in combination with pembrolizumab. In Part 2 of the study, subjects will be initially enrolled in Stage 1 of parallel expansion cohorts of FLX475 as monotherapy or in combination with pembrolizumab.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Advanced Cancer | Drug: FLX475 Drug: Pembrolizumab | Phase 1 Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 375 participants |
Allocation: | Non-Randomized |
Intervention Model: | Sequential Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | Phase 1/2 Dose-Escalation and Expansion Study of FLX475 Alone and in Combination With Pembrolizumab in Advanced Cancer |
Actual Study Start Date : | September 25, 2018 |
Estimated Primary Completion Date : | June 2023 |
Estimated Study Completion Date : | December 2023 |

Arm | Intervention/treatment |
---|---|
Experimental: Part 1a: Monotherapy Dose Escalation
Eligible subjects will be enrolled in sequential cohorts treated with successively higher doses of FLX475 as monotherapy.
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Drug: FLX475
tablet |
Experimental: Part 1b: Combination Dose Escalation
Eligible subjects will be enrolled in sequential cohorts treated with successively higher doses of FLX475 in combination with pembrolizumab.
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Drug: FLX475
tablet Drug: Pembrolizumab IV infusion
Other Name: Keytruda |
Experimental: Part 2a: Monotherapy Expansion Cohorts
Eligible subjects will be initially enrolled in Stage 1 of parallel expansion cohorts of FLX475 as monotherapy; additional subjects in each cohort may be enrolled in Stage 2.
|
Drug: FLX475
tablet |
Experimental: Part 2b: Combination Expansion Cohorts
Eligible subjects will be initially enrolled in Stage 1 of parallel expansion cohorts of FLX475 in combination with pembrolizumab; additional subjects in each cohort may be enrolled in Stage 2.
|
Drug: FLX475
tablet Drug: Pembrolizumab IV infusion
Other Name: Keytruda |
- Safety and tolerability of FLX475 as a single agent and in combination with pembrolizumab measured by the incidence of adverse events, including dose-limiting toxicities and maximum tolerated dose [ Time Frame: Approximately 18 weeks ]
- Overall response rate in subjects treated with FLX475 as a single agent and in combination with pembrolizumab [ Time Frame: Through study completion (approximately 2 years) ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
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Documented advanced or metastatic cancer ineligible for standard therapies with one of the following histologies
- Dose Escalation: non-small cell lung cancer, head and neck squamous cell carcinoma, nasopharyngeal carcinoma, metastatic triple negative breast cancer, urothelial carcinoma, gastric cancer, esophageal carcinoma, cervical cancer, classical Hodgkin lymphoma
- Dose Expansion: nasopharyngeal carcinoma, lymphoma, head and neck squamous cell carcinoma, cervical cancer, non-small cell lung cancer, triple-negative breast cancer
- Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1
- Evaluable disease at baseline (at least one measurable target lesion by imaging for expansion cohorts)
- Tumor available for biopsy
Exclusion Criteria:
- History of allergy or severe hypersensitivity to biologic agents
- History of Grade 3-4 immune-related adverse events leading to discontinuation of prior immuno-oncology treatment
- Active autoimmune disease or serious autoimmune disease within past 2 years requiring systemic therapy
- History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, idiopathic pneumonitis, (non-infectious) pneumonitis that required steroids, or symptoms of active pneumonitis
- Prior allogeneic hematopoietic stem cell transplant within 5 years, or prior allogeneic organ transplant
- Active graft-versus-host disease

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03674567
Contact: Clinical Trial Manager | 650-489-9000 | clinical.trials@rapt.com |

Study Director: | William Ho, MD, PhD | RAPT Therapeutics, Inc. |
Responsible Party: | RAPT Therapeutics, Inc. |
ClinicalTrials.gov Identifier: | NCT03674567 |
Other Study ID Numbers: |
FLX475-02 KEYNOTE-877 ( Other Identifier: Merck Sharp & Dohme Corp. ) |
First Posted: | September 17, 2018 Key Record Dates |
Last Update Posted: | June 14, 2022 |
Last Verified: | June 2022 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Non-small Cell Lung Cancer Head and Neck Squamous Cell Carcinoma Breast Cancer Urothelial Carcinoma |
Nasopharyngeal Carcinoma Cervical Cancer Lymphoma |
Neoplasms Pembrolizumab Antineoplastic Agents, Immunological |
Antineoplastic Agents Immune Checkpoint Inhibitors Molecular Mechanisms of Pharmacological Action |