MC# 19-31 - A Phase I, Open-label, Multicenter Study of SYNB1891 Administered by Intratumoral Injection to Patients with Advanced/Metastatic Solid Tumors and Lymphoma Alone and in Combination with Atezolizumab

  • Agent(s): SYNB1891
  • Disease Type(s): Bladder, Gastric, Lung-NSCLC, Merkel Cell
  • Phase(s): I
  • Drug Classification(s): Immunotherapy, Gene Therapy
  • Molecular Target(s): STING

Mechanism of Action

SYNB1891, is an engineered strain of live E. coli designed to act as a dual innate immune activator, STING agonist.


In this study, the sponsor and investigators want to learn:

  • How much of SYNB1891 can be given with or without Atezolizumab with an acceptable level of side effects
  • The effects of SYNB1891 when with or without Atezolizumab (good and bad)
  • How much of SYNB1891 is absorbed into the blood and how fast it is removed
  • How proteins that indicate the status of your disease are affected with use of SYNB1891 when with or without Atezolizumab
  • If SYNB1891 when with or without Atezolizumab prevents or delays tumor growth
Inclusion Criteria
  • Able and willing to voluntarily complete the informed consent process (patient or patient’s representative)
  • Adults aged ≥ 18 years (on the day of signing informed consent) with histologically- or cytologically-confirmed stage III or IV advanced/metastatic solid tumor or lymphoma that is not surgically resectable and for which no therapeutic options are available to extend survival or for which the patient is not a candidate for standard-of-care therapy
  • Eastern Cooperative Oncology Group performance status ≤ 1
  • Life expectancy ≥ 3 months
  • ≥ 1 injectable, measurable (≥ 10 mm in diameter, or ≥ 15 mm for nodal lesions), eligible lesion as defined by RECIST 1.1, iRECIST, and/or LYRIC and as assessed by the Investigator.  Eligible lesions must be nonvisceral and must not be located in either the thoracic, abdominal, or pelvic cavities or in the cranium and must be amenable to percutaneous injection and away from major blood vessels or neurological structures.
  • Able to provide biopsies for biomarker analysis from injected and (if available) noninjected lesions at baseline and other time points during the study
  • Normal oxygenation without the use of supplemental oxygen
  • Adequate cardiac function, defined as follows:
    • Left ventricular ejection fraction (LVEF) > 50% by multi-gated acquisition (MUGA) scan or echocardiogram (ECHO) performed within 6 months prior to the first dose of study treatment provided the patient has not received any potential cardiotoxic agents in the intervening period.  Symptoms relating to left ventricular dysfunction, cardiac arrhythmia, or cardiac ischemia must all be < Grade 1.
    • QTc interval corrected for heart rate using Fridericia’s formula (QTcF) < 480 msec at screening
  • Laboratory values within the following ranges:
    • Absolute neutrophil count ≥ 1500/µL
    • Lymphocyte count ≥ 500/µL
    • Platelets ≥ 100,000/µL without transfusion
    • Hemoglobin ≥ 9.0 g/dL or ≥ 5.6 mmol/L1 (patients may be transfused to meet this criterion)
    • Estimated glomerular filtration rate (eGFR) > 50 mL/min/1.73 m2
    • Total bilirubin ≤ 1.5 × the upper limit of normal (ULN) OR direct bilirubin ≤ ULN for participants with total bilirubin levels > 1.5 × ULN (elevated indirect bilirubin because of Gilbert’s syndrome is permitted)
    • AST, ALT, and alkaline phosphatase ≤ 2.5 × ULN (AST and ALT ≤ 5 × ULN for participants with liver metastases and alkaline phosphatase ≤ 5 × ULN for participants with liver or bone metastases)
    • Albumin ≥ 2.5 g/dL
    • International normalized ratio (INR) or PT or aPTT ≤ 1.5 × ULN unless participant is receiving anticoagulant therapy as long as PT or aPTT is within therapeutic range of intended use of anticoagulants
    • TSH within the normal reference range or on stable thyroid replacement therapy
  • Agree to use an acceptable method of contraception after informed consent, throughout the study, and for 5 months after the last dose of SYNB1891 or atezolizumab

Additional inclusion criteria that apply only to Arm 2 study participants are as follows:

  • Patients must have progressed on treatment with an anti-PD-1/L1 monoclonal antibody (mAb) administered either as monotherapy, or in combination with other CPIs or other therapies, if indicated (if CPI therapy is not indicated as a part of standard of care therapy, patients may be CPI naïve)
    • PD-1 treatment progression is defined by meeting all of the following criteria:
      • Has received at least 2 doses of an approved anti-PD-1/L1 mAb
      • Has demonstrated disease progression after PD-1/L1 as defined by RECIST 1.1, iRECIST, and/or LYRIC.  The initial evidence of disease progression is to be confirmed by a second assessment no less than 4 weeks from the date of the first documented disease progression, in the absence of rapid clinical progression as determined by the Investigator.  Once disease progression is confirmed, the initial date of disease progression documentation will be considered the date of disease progression.
      • Progressive disease has been documented within 12 weeks from the last dose of anti-PD-1/L1 mAb


Exclusion Criteria
  • Chemotherapy, radiation, or biological cancer therapy within 14 days prior to the first dose of study treatment, or failure of any AEs to recover to Baseline or NCI CTCAE Grade 1, except for any grade of alopecia from AEs caused by cancer therapeutics administered > 28 days earlier
  • Systemic immunostimulatory agents (including, but not limited to, IFN and IL-2) within 28 days or 5 drug elimination half-lives (whichever is longer) prior to initiation of study treatment
  • Allogeneic hematopoietic stem cell transplantation within the last 5 years (patients who have had a transplant > 5 years ago are eligible provided that no symptoms of graft-versus-host disease are present) that requires current use of immunosuppressors
  • Receipt of a live vaccine within 90 days prior to the first dose of study treatment or anticipation of a need for such a vaccine during treatment
  • Receipt of warfarin or other oral anticoagulants within 7 days prior to the first dose of study treatment.  Patients may switch to enoxaparin, with holding of the dose the day before i.t. injection of SYNB1891 (if holding the dose is not contraindicated).
  • Receipt of antibiotics within 7 days prior to the first dose of study treatment
  • Participation in a study of an investigational agent and receipt of study therapy or use of an investigational device within 28 days prior to the first dose of study treatment
  • Diagnosed immunodeficiency or current use of chronic systemic steroid therapy in excess of replacement doses (prednisone ≤ 10 mg/day or equivalent is acceptable) or any other form of immunosuppressive medication within 7 days prior to the first dose of study treatment
  • Anticipated requirement of any other form of antineoplastic therapy while on study
  • History of a second malignancy, unless potentially curative treatment has been completed, with no evidence of malignancy for 2 years
  • Clinically active central nervous system (CNS) metastases and/or carcinomatous meningitis (stable brain metastases are permitted if treatment was completed ≥ 28 days prior to the first dose of study treatment)
  • History of immune-mediated vasculitis, pancreatitis, colitis, hepatitis, or nephritis
  • History of immune-related AEs requiring discontinuation of prior PD-1/PD-L1 therapy
  • Active or history of autoimmune disease or immune deficiency, including, but not limited to, myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, antiphospholipid antibody syndrome, Wegener granulomatosis, Sjögren syndrome, Guillain-Barré syndrome, or multiple sclerosis, with the following exceptions:
    • Patients with a history of autoimmune-related hypothyroidism who are on thyroid replacement hormone are eligible for the study
    • Patients with controlled Type 1 diabetes mellitus who are on an insulin regimen are eligible for the study
    • Patients with eczema, psoriasis, lichen simplex chronicus, or vitiligo with dermatologic manifestations only (e.g., patients with psoriatic arthritis are excluded) are eligible for the study provided all of following conditions are met:
      • Rash must cover < 10% of body surface area;
      • Disease is well controlled at baseline and requires only low-potency topical corticosteroids;
      • No occurrence of acute exacerbations of the underlying condition requiring psoralen plus ultraviolet A radiation, methotrexate, retinoids, biologic agents, oral calcineurin inhibitors, or high potency or oral corticosteroids within the previous 12 months
  • Allergy to antibiotics that precludes treatment for infection with E. coli Nissle 1917
  • Human immunodeficiency virus (HIV) and/or hepatitis B or C infection(s) unless screening tests indicate negative viral load
  • Known active tuberculosis
  • Grade 3 or higher infection according to NCI CTCAE within 28 days prior to initiation of study treatment, including, but not limited to, hospitalization for complications of infection, bacteremia, or severe pneumonia
  • Failure to fully recover from the effects of major surgery.  Surgeries that required general anesthesia must be completed > 14 days before the first dose of study drug. Surgery requiring regional/epidural anesthesia must be completed > 72 hours before the first dose of study treatment and participants should be recovered.
  • Heart failure of New York Heart Association Class 3 or greater, history of pericardial disease, restrictive cardiomyopathy, or unstable angina or recent myocardial infarction within 3 to 6 months prior to the first dose of study treatment
  • Any other medical condition that might confound the results of the study, interfere with the participant’s participation, or is not in the best interest of the participant, in the opinion of the treating Investigator
  • Pregnant or breastfeeding or anticipated conception or fathering of children within the projected duration of the study and for 5 months after the last dose of SYNB1891 or atezolizumab

Additional exclusion criteria that apply only to Arm 2 study participants are as follows:

  • History of a severe allergic anaphylactic reaction following treatment with a PD-1 mAb or to chimeric or humanized antibodies or fusion proteins
  • History of idiopathic pulmonary fibrosis, organizing pneumonia (e.g., bronchiolitis obliterans), drug-induced pneumonitis requiring treatment, or idiopathic pneumonitis, or evidence of active pneumonitis on screening chest CT scan


  • Dallas, TX - Mary Crowley Cancer Research - Medical City
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Re: MC# 19-31