Pembrolizumab, Capecitabine, and Bevacizumab in Treating Patients With Microsatellite Stable Colorectal Cancer That Is Locally Advanced, Metastatic, or Cannot Be Removed by Surgery

Stage IV Colorectal Cancer AJCC v7 Clinical Trial

Official title: Phase II Study of Pembrolizumab Plus Capecitabine and Bevacizumab in Microsatellite Stable Metastatic Colorectal Cancer

Status Completed

Clinical Trial Summary

This phase II trial studies the side effects and best dose of capecitabine when given together with pembrolizumab and bevacizumab, and investigates how well they work in treating patients with microsatellite stable colorectal cancer that has spread to nearby tissues or lymph nodes, has spread to other places in the body, or that cannot be removed by surgery. Monoclonal antibodies, such as pembrolizumab and bevacizumab, may interfere with the ability of tumor cells to grow and spread. Drugs used in chemotherapy, such as capecitabine, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving capecitabine together with pembrolizumab and bevacizumab may work better in treating patients with colorectal cancer.

Clinical Trial Description

PRIMARY OBJECTIVES:

I. To determine the recommended phase 2 dose (RP2D)/maximum tolerated dose (MTD) of capecitabine when administered with pembrolizumab and bevacizumab. (Safety Lead-In Cohort) II. To evaluate the overall response rate (ORR) to pembrolizumab plus capecitabine and bevacizumab (complete or partial response rate per Response Evaluation Criteria in Solid Tumors [RECIST] 1.1) in subjects with metastatic or locally advanced unresectable microsatellite stable (MSS)/mismatch repair proficient (pMMR) colorectal carcinoma (CRC) that is stable or progressing on fluorouracil (5FU)-based therapy. (Phase II Expansion Cohort)

SECONDARY OBJECTIVES (Phase II Expansion Cohort):

I. To determine the safety and tolerability of pembrolizumab in combination with capecitabine and bevacizumab.

II. To evaluate ORR per immune-related RECIST (irRECIST). III. To evaluate duration of response (DOR), disease control rate (DCR) and progression-free survival (PFS) per RECIST 1.1 and irRECIST and overall survival (OS).

EXPLORATORY OBJECTIVES:

I. Correlation of outcomes to line of therapy; stable disease or progression on a prior regimen containing infusional 5-FU or capecitabine; prior exposure to bevacizumab; and primary tumor location.

II. To explore baseline immune profiles via PD-L1, and multiplex Immunohistochemistry (IHC) for identification of potentially predictive biomarkers in patients with metastatic or locally advanced, unresectable CRC treated with pembrolizumab-based combination therapy.

III. To characterize the change in the populations of tumor-infiltrating immune cells (TIICs) by IHC induced by pembrolizumab-based combination therapy in paired pre- and on-treatment tumor biopsies from patients with metastatic or locally advanced, unresectable MSS / pMMR CRC.

IV. To determine the change in T cell repertoire via next generation sequencing (NGS) within blood and tumor biopsy samples induced by pembrolizumab-based combination therapy in patients with metastatic or locally advanced, unresectable MSS/pMMR CRC.

V. To establish human immune system (HIS) patient-derived xenograft (PDX) models from pre-treatment biopsies to a) analyze change in immune cell profiles HIS PDX models using the same techniques as described for corresponding patients, above and b) correlate response to pembrolizumab-containing therapy in patients and HIS PDX.

OUTLINE:

An initial safety lead-in will be performed to define the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D). Patients receive pembrolizumab intravenously (IV) over 30 minutes on day 1, bevacizumab IV over 30-90 minutes on day 1, and capecitabine orally (PO) twice daily (BID) on days 1-14. Treatment repeats every 3 weeks for up to 35 courses in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 30 days, every 9 weeks until disease progression, start of new anti-cancer therapy, death, or end of the study whichever comes first ;

Related Conditions & MeSH terms

• Colorectal Neoplasms
• Microsatellite Stable
• Mismatch Repair Protein Proficient
• Stage III Colorectal Cancer AJCC v7
• Stage IIIB Colorectal Cancer AJCC v7
• Stage IIIC Colorectal Cancer AJCC v7
• Stage IV Colorectal Cancer AJCC v7
• Stage IVA Colorectal Cancer AJCC v7
• Stage IVB Colorectal Cancer AJCC v7

• NCT number: NCT03396926
• Study type: Interventional
• Source: University of California, San Francisco
• Status: Completed
• Phase: Phase 2
• Start date: April 18, 2018
• Completion date: January 30, 2024