Study of Anti-PD-L1 in Combination With Chemo(Radio)Therapy for Oesophageal Cancer

This is an open-label, Phase 1/2 study to evaluate the safety of immunotherapy in combination with chemo (radio) therapy with the following cohorts:

• Cohorts A1, A2, and B: Oxaliplatin/capecitabine chemotherapy in metastatic/locally advanced oesophageal cancer (OC).
• Cohort C: Neoadjuvant oxaliplatin/capecitabine chemotherapy before surgery in operable OC.
• Cohort C-FLOT: Neoadjuvant 5-fluorouracil (5-FU), leucovorin, oxaliplatin, and docetaxel (FLOT) chemotherapy before surgery in operable OC.
• Cohort D/D2: Neoadjuvant paclitaxel/carboplatin chemotherapy + radiotherapy before surgery in operable OC.

The immunotherapy will be given for a 4-week period before starting the standard chemo(radio)therapy, continuing durvalumab treatment once the chemotherapy starts for all cohorts except Cohort D.

The study will include 2 phases, a safety run-in Phase 1 (Cohorts A1 and A2) and an expansion Phase 2 (Cohorts B including the higher dose tremelimumab cohort from Cohort A2, C, C-FLOT, and D/D2).

Phase 1 will evaluate the safety of durvalumab alone (Cohort A1) administered before chemotherapy (oxaliplatin + capecitabine) in subjects with metastatic or locally advanced OC. After completion of Cohort A1, Phase 2 in Cohorts C, C-FLOT, and D/D2 will begin, and a safety review will determine whether to explore the tremelimumab + durvalumab combination (Cohort A2).

Phase 2 includes the expansion into Cohorts B, C, C-FLOT, and D/D2. Once Cohort A1 is cleared, there will be concurrent enrollment into Phase 2 expansion for Cohorts C, C-FLOT and D/D2 (subjects with operable OC with neoadjuvant chemotherapy or chemoradiotherapy before surgery) and the tremelimumab dose-escalation phase for Cohort A2 (37.5 mg and 75 mg). Once Cohort A2 is completed, another safety review will determine the dose of tremelimumab to be included in the recommended combination dose (RCD) to start enrollment into the Cohort B (subjects with metastatic/locally advanced OC) expansion phase. Subjects treated at the RCD in Cohort A2 (tremelimumab 75 mg) will be included in Cohort B.

Subjects in Cohorts C, C-FLOT and D/D2 will undergo surgery after completing treatment, and they will be eligible to resume durvalumab dosing (to a maximum of 12 infusions) once recovered from surgery, provided that this is within 3 months of surgery. Subjects in Cohort C-FLOT may receive durvalumab, FLOT, or durvalumab plus FLOT at the discretion of the investigator.

Inclusion criteria

• Histological diagnosis of oesophageal or gastrooesophageal cancer and have not received prior chemotherapy.

• Cohorts A and B - metastatic/locally advanced cancer
• Cohorts C/C-FLOT and D/D2 - deemed suitable for surgery with curative intent
• Anticipated lifespan greater than 4 months.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• At the time of day 1 of the study, subjects with brain metastases must be asymptomatic for at least 4 weeks and:

• at least 8 weeks without tumour progression after any whole brain radiotherapy
• at least 4 weeks since craniotomy and resection or stereotactic radiosurgery
• at least 3 weeks without new brain metastases as evidenced by MRI/CT
• Adequate normal organ and marrow function. Laboratory parameters for vital functions should be in the normal range. Laboratory abnormalities that are not clinically significant are generally permitted.
• Written informed consent obtained from the subject; subject been informed of other treatment options, and able to comply with study requirements.
• Age 18 years or older.

Exclusion criteria

• Involvement in the planning and/or conduct of the study (applies to both AstraZeneca staff and/or staff at the study site). Previous enrollment in the present study.
• Participation in another clinical study with an investigational product during the last 4 weeks.
• Mean QT interval corrected for heart rate (QTc) ≥470 ms calculated from 3 electrocardiograms (ECGs) using Fredericia's Correction.
• Active or prior documented inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis).
• History of allogeneic organ transplant.
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, uncontrolled hypertension, unstable angina pectoris, cardiac arrhythmia, active peptic ulcer disease or gastritis, active bleeding diatheses including any subject known to have evidence of acute or chronic hepatitis B, hepatitis C, known immunodeficiency or human immunodeficiency virus (HIV), or psychiatric illness/social situations that would limit compliance with study requirements or compromise the ability of the subject to give written informed consent.
• Known history of previous clinical diagnosis of tuberculosis.
• History of pneumonitis or interstitial lung disease.