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Safety and Tolerability of SYNB1891 Injection Alone or in Combination With Atezolizumab in Adult Participants

A Phase 1, 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

Status
Terminated
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04167137
Enrollment
32
Registered
2019-11-18
Start date
2019-12-12
Completion date
2021-12-09
Last updated
2024-05-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Lymphoma, Metastatic Solid Neoplasm

Keywords

solid tumor

Brief summary

This Phase 1, open-label, multicenter, 2-arm study was designed to evaluate SYNB1891 when administered either as monotherapy (Arm 1) or in combination with atezolizumab (Arm 2) in participants with advanced/metastatic solid tumors or lymphoma. The primary objective was to evaluate the safety and tolerability of study treatment, with a secondary objective of assessing preliminary tumor response to treatment and exploratory objectives of evaluating the pharmacokinetics/pharmacodynamics (PK/PD) of study treatment.

Detailed description

Arm 1 comprised intratumoral (IT) injections of SYNB1891 monotherapy to determine the single-agent maximum tolerated dose (MTD). The starting dose of SYNB1891 in the first cohort was 1 × 10\^6 live cells and was increased in approximately 3-fold increments in subsequent cohorts until MTD determination in accordance with the modified toxicity probability interval (mTPI) algorithm (Ji et al 2013). Dose escalation was to proceed until the target dose-limiting toxicity (DLT) range (approximately 30%) for SYNB1891 monotherapy was determined based on DLTs observed in Cycle 1. The dose selected as achieving the target DLT range was to be considered the MTD. DLTs were defined in the protocol as certain treatment-related Grade 3/4 laboratory values, sepsis, toxicity resulting in death, discontinuation of Cycle 1, or delay of Cycle 2. Arm 2 comprised IT injections of SYNB1891 combined with standard dose atezolizumab (1200 mg intravenously \[IV\] every 3 weeks \[Q3W\]). Arm 2 dosing began after all participants in Arm 1 Cohort 4 completed their Cycle 1 DLT safety evaluation. The starting dose of IT SYNB1891 in the first cohort of Arm 2 was at the SYNB1891 Arm 1 Cohort 3 dose level. SYNB1891 dosing in the Arm 2 cohorts increased in approximately 3-fold increments in subsequent cohorts until recommended Phase 2 dose (RP2D) determination. SYNB1891 combination dosing in Arm 2 was always at least 1 dose level below the SYNB1891 monotherapy dose being evaluated in Arm 1, with combination doses not escalated above the SYNB1891 single-agent MTD established in Arm 1. In both arms, after an initial 4 cycles (21 days per cycle) of study treatment, participants who did not have progressive disease may have received additional cycles of their assigned study treatment for up to 24 months (i.e., Cycles 5 to 35) after the initial dose. The maximum time of study participation for a participant may have been up to 26 months, including the screening period (up to 28 days), treatment administration period (up to 24 months), and Safety Follow-up period (30 ± 5 days after the last dose).

Interventions

DRUGSYNB1891

SYNB1891 was administered as an IT injection over a dose range of 1 x 10\^6 to 3 x 10\^8 live cells in Arm 1 and 1 x 10\^7 to 3 x 10\^7 in Arm 2.

DRUGAtezolizumab

Atezolizumab was administered in accordance with its recommended dose and schedule (1200 mg IV Q3W).

Sponsors

IQVIA Biotech
CollaboratorINDUSTRY
Synlogic
Lead SponsorINDUSTRY

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Dose-escalating, open-label

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Able and willing to voluntarily complete the informed consent process (participant or participant's representative). 2. 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 for which no therapeutic options were available to extend survival or for which the participant was not a candidate for standard-of-care therapy. 3. Eastern Cooperative Oncology Group performance status ≤ 1. 4. Life expectancy ≥ 3 months. 5. ≥ 1 injectable, measurable (≥ 10 mm in diameter, or ≥ 15 mm for nodal lesions), eligible lesion as defined by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 (Eisenhauer et al 2009), immune-related RECIST (iRECIST) (Seymour et al 2017), and/or Lymphoma Response to Immunomodulatory Therapy Criteria (LYRIC) (Cheson et al 2016) and as assessed by the Investigator. Eligible lesions must not have been located in the thoracic cavity, spleen, pancreas, gastrointestinal tract (liver injection allowed), or cranium and must have been amenable to percutaneous injection and away from major blood vessels or neurological structures. 6. Able to provide biopsies for biomarker analysis from injected and (if available) noninjected lesions at baseline and other time points during the study. 7. Oxygen saturation \> 90% without the use of supplemental oxygen. 8. Adequate cardiac function, defined as follows: 1. 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 participant had not received any potential cardiotoxic agents in the intervening period. Symptoms relating to left ventricular dysfunction, cardiac arrhythmia, or cardiac ischemia must all have been Grade \< 1 per National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. 2. QTc interval corrected for heart rate using Fridericia's formula (QTcF) \< 480 msec at screening. 9. 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 (participants may have been transfused to meet this criterion) * Estimated glomerular filtration rate (eGFR) \> 50 mL/min/1.73 m\^2 per the Cockcroft-Gault formula * Total bilirubin ≤ 1.5 × upper limit of normal (ULN) OR direct bilirubin ≤ ULN for participants with total bilirubin levels \> 1.5 × ULN or ≤ 3 × ULN for participants with Gilbert's syndrome * Aspartate aminotransferase (AST), alanine aminotransferase (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) * International normalized ratio (INR) or prothrombin time (PT) or activated partial thromboplastin time (aPTT) ≤ 1.5 × ULN unless participant was receiving anticoagulant therapy as long as PT or aPTT was within therapeutic range of intended use of anticoagulants 10. Agreed 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 applied only to Arm 2 study participants were as follows: 11. Thyroid-stimulating hormone (TSH) within the normal reference range or the participant was receiving stable thyroid replacement therapy. 12. Participants must have received treatment with an anti-programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) monoclonal antibody (mAb) administered either as monotherapy, or in combination with other checkpoint inhibitors (CPIs) or other therapies, if indicated (if CPI therapy was not indicated as a part of standard-of-care therapy, participants may have been CPI naïve).

Exclusion criteria

1. Chemotherapy, radiation, or biological cancer therapy within 14 days prior to the first dose of study treatment, or failure of any adverse events (AEs) to recover to Baseline or NCI CTCAE version 5.0 Grade 1, except for any grade of alopecia caused by cancer therapeutics administered \> 28 days earlier. 2. Systemic immunostimulatory agents (including, but not limited to, interferon and interleukin-2) within 28 days or 5 drug elimination half-lives (whichever was longer) prior to initiation of study treatment. CPIs were not considered systemic immunostimulatory agents for this criterion and were subject to the washout period listed in exclusion criterion #1. 3. Allogeneic hematopoietic stem cell transplantation that required current use of immunosuppressors. 4. 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. 5. Receipt of antibiotics within 7 days prior to the first dose of study treatment. 6. 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. 7. Diagnosed immunodeficiency or current use of chronic systemic steroid therapy in excess of replacement doses (prednisone ≤ 10 mg/day or equivalent was acceptable) or any other form of immunosuppressive medication within 7 days prior to the first dose of study treatment. 8. For injection and biopsy of visceral (deep) lesions: participants must not have been on long-acting antiplatelet agents such as aspirin or clopidogrel or on therapeutic doses of anticoagulants, with the exception of participants receiving a preventative dose of low molecular weight heparin. In participants receiving preventative low molecular weight heparin, treatment must have been stopped 24 hours before the intratumoral injection and resumed again 24 hours after the injection (Marabelle et al 2018). 9. Previous or concurrent malignancy, with the exception of: 1. Adequately treated basal or squamous cell carcinoma, in situ carcinoma of the cervix, or ductal carcinoma in situ of the breast; 2. Localized prostate cancer definitively treated with surgery or radiation or stable on hormone therapy; 3. Other cancer from which the participant had been disease free for at least 2 years. 10. Clinically active central nervous system metastases and/or carcinomatous meningitis (treated brain metastases were permitted if radiologically stable for ≥ 28 days prior to the first dose of study treatment). 11. Allergy to antibiotics that precluded treatment for infection with Escherichia coli Nissle 1917. 12. Hepatitis B or C infection(s) unless screening tests indicated a negative viral load, and/or human immunodeficiency virus infection unless screening tests indicated a negative or below the limit of quantitation viral load. 13. Known active tuberculosis. 14. 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. 15. Failure to fully recover from the effects of major surgery. Surgeries that required general anesthesia must have been completed \> 14 days before the first dose of study drug. Surgery requiring regional/epidural anesthesia must have been completed \> 72 hours before the first dose of study treatment and participants should have recovered. 16. Heart failure of New York Heart Association Class 3 or greater, restrictive cardiomyopathy, or unstable angina or recent myocardial infarction within 3 months prior to the first dose of study treatment. 17. Any other medical condition that might have confounded the results of the study, interfered with the participant's participation, or was not in the best interest of the participant, in the opinion of the treating Investigator. 18. 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

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Dose-limiting Toxicity21 days (1 cycle)The following adverse events (AEs) were DLTs if they occurred in Cycle 1 and were assessed by the Investigator as related to treatment: 1. Grade (Gr) 4 nonhematologic toxicity (not laboratory) 2. Gr 4 hematologic toxicity ≥ 7 days, any Gr 4 thrombocytopenia, or Gr 3 thrombocytopenia with significant bleeding 3. Gr ≥ 3 nonhematologic toxicity (exceptions: Gr 3 fatigue ≤ 3 days; Gr 3 diarrhea, nausea, or vomiting without treatment; Gr 3 rash without treatment) 4. Gr 3/4 nonhematologic laboratory value for \> 1 week or resulting in significant medical intervention, hospitalization, or drug-induced liver injury (exceptions: clinically nonsignificant, treatable, or reversible laboratory abnormalities) 5. Gr 3/4 febrile neutropenia 6. Sepsis, severe abscesses and/or ulcerations requiring surgical management 7. Toxicity delaying Cycle 2 initiation \>2 weeks 8. Toxicity causing treatment discontinuation 9. Gr 3 toxicity causing omission of \> 33% of study doses 10. Gr 5 toxicity

Secondary

MeasureTime frameDescription
Number of Participants With Treatment-Emergent Adverse EventsUp to 13 monthsToxicity was graded in accordance with the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE), version 5.0, as follows: Grade 1 (mild/asymptomatic; no intervention); Grade 2 (moderate; minimal intervention); Grade 3 (severe/medically significant; hospitalization indicated; disabling); Grade 4 (life-threatening; urgent intervention required); or Grade 5 (fatal). Adverse events (AEs) were reported from clinical laboratory tests, vital sign and weight measurements, physical examinations, and any other medically indicated assessments, including participant interviews, from the time informed consent was signed through the end of the safety follow-up period. AEs were considered to be treatment-emergent adverse events (TEAEs) if they occurred or worsened in severity after the first dose of study treatment. TEAEs were considered treatment-related if the relationship to study drug was possibly, probably, or definitely related.
Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)Up to 13 monthsAppropriate imaging of the SYNB1891-injected tumor(s) and up to 5 target (noninjected) lesions was performed at baseline and every 2 cycles during the treatment period. Tumor response was assessed by the local investigator using RECIST 1.1 (Eisenhauer et al 2009). Per RECIST 1.1, target lesions are categorized as follows: complete response (CR): disappearance of all target lesions (no evaluable disease); partial response (PR): ≥ 30% decrease in the sum of the longest diameter of target lesions; progressive disease (PD): ≥ 20% increase in the sum of the longest diameter of target lesions; stable disease (SD): small changes that do not meet above criteria.

Countries

United States

Participant flow

Participants by arm

ArmCount
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles.
3
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles.
3
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles.
4
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles.
5
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles.
3
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles.
6
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + Atezolizumab
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles in combination with standard dose atezolizumab (1200 mg IV Q3W) on Day 1 of each cycle.
4
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + Atezolizumab
SYNB1891 was administered as an IT injection on Days 1, 8, and 15 of Cycle 1 and Day 1 of subsequent cycles in combination with standard dose atezolizumab (1200 mg IV Q3W) on Day 1 of each cycle.
4
Total32

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003FG004FG005FG006FG007
Overall StudyAdverse Event00000101
Overall StudyDeath01000000
Overall StudyDisease progression11332322
Overall StudyPhysician Decision00010010
Overall StudyStudy terminated by Sponsor00000001
Overall StudyWithdrawal by Subject10010210

Baseline characteristics

CharacteristicArm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabArm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
1 Participants0 Participants1 Participants2 Participants0 Participants5 Participants1 Participants1 Participants11 Participants
Age, Categorical
Between 18 and 65 years
2 Participants3 Participants3 Participants3 Participants3 Participants1 Participants3 Participants3 Participants21 Participants
Age, Continuous62.0 years58.0 years53.5 years57.0 years63.0 years74.5 years59.5 years60.5 years61.5 years
Disease type
Ampullary bile duct adenocarcinoma
0 Participants0 Participants1 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants
Disease type
Basal cell carcinoma
0 Participants1 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants
Disease type
Cecum adenocarcinoma
0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants0 Participants0 Participants1 Participants
Disease type
Colorectal cancer
0 Participants0 Participants0 Participants1 Participants0 Participants0 Participants0 Participants0 Participants1 Participants
Disease type
Endometrial cancer
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants1 Participants
Disease type
Esophageal cancer
0 Participants1 Participants0 Participants0 Participants0 Participants0 Participants2 Participants1 Participants4 Participants
Disease type
Jejunum adenocarcinoma
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants0 Participants1 Participants
Disease type
Melanoma
1 Participants0 Participants0 Participants1 Participants2 Participants3 Participants0 Participants1 Participants8 Participants
Disease type
Merkel cell carcinoma
0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants0 Participants0 Participants1 Participants
Disease type
Non-small cell lung cancer
0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants0 Participants0 Participants1 Participants
Disease type
Rectosigmoid adenocarcinoma
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants0 Participants1 Participants
Disease type
Sarcoma
2 Participants1 Participants1 Participants1 Participants0 Participants0 Participants0 Participants0 Participants5 Participants
Disease type
Small cell lung cancer
0 Participants0 Participants1 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants
Disease type
Squamous cell carcinoma (oropharynx)
0 Participants0 Participants0 Participants1 Participants1 Participants0 Participants0 Participants0 Participants2 Participants
Disease type
Squamous cell carcinoma (skin)
0 Participants0 Participants1 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants
Disease type
Squamous cell carcinoma (vulva)
0 Participants0 Participants0 Participants1 Participants0 Participants0 Participants0 Participants0 Participants1 Participants
Disease type
Testicular cancer
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants1 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants0 Participants0 Participants0 Participants0 Participants0 Participants1 Participants0 Participants2 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
2 Participants3 Participants4 Participants5 Participants3 Participants6 Participants3 Participants4 Participants30 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
1 Participants0 Participants1 Participants0 Participants0 Participants1 Participants0 Participants0 Participants3 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
2 Participants3 Participants3 Participants5 Participants3 Participants5 Participants4 Participants4 Participants29 Participants
Region of Enrollment
United States
3 Participants3 Participants4 Participants5 Participants3 Participants6 Participants4 Participants4 Participants32 Participants
Sex: Female, Male
Female
3 Participants2 Participants3 Participants4 Participants1 Participants4 Participants2 Participants1 Participants20 Participants
Sex: Female, Male
Male
0 Participants1 Participants1 Participants1 Participants2 Participants2 Participants2 Participants3 Participants12 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
EG005
affected / at risk
EG006
affected / at risk
EG007
affected / at risk
deaths
Total, all-cause mortality
2 / 32 / 30 / 41 / 50 / 30 / 60 / 41 / 4
other
Total, other adverse events
3 / 33 / 34 / 45 / 53 / 36 / 64 / 44 / 4
serious
Total, serious adverse events
1 / 31 / 31 / 43 / 50 / 33 / 60 / 42 / 4

Outcome results

Primary

Number of Participants With Dose-limiting Toxicity

The following adverse events (AEs) were DLTs if they occurred in Cycle 1 and were assessed by the Investigator as related to treatment: 1. Grade (Gr) 4 nonhematologic toxicity (not laboratory) 2. Gr 4 hematologic toxicity ≥ 7 days, any Gr 4 thrombocytopenia, or Gr 3 thrombocytopenia with significant bleeding 3. Gr ≥ 3 nonhematologic toxicity (exceptions: Gr 3 fatigue ≤ 3 days; Gr 3 diarrhea, nausea, or vomiting without treatment; Gr 3 rash without treatment) 4. Gr 3/4 nonhematologic laboratory value for \> 1 week or resulting in significant medical intervention, hospitalization, or drug-induced liver injury (exceptions: clinically nonsignificant, treatable, or reversible laboratory abnormalities) 5. Gr 3/4 febrile neutropenia 6. Sepsis, severe abscesses and/or ulcerations requiring surgical management 7. Toxicity delaying Cycle 2 initiation \>2 weeks 8. Toxicity causing treatment discontinuation 9. Gr 3 toxicity causing omission of \> 33% of study doses 10. Gr 5 toxicity

Time frame: 21 days (1 cycle)

Population: All participants who were enrolled, allocated to treatment, and received at least 1 dose of investigational product.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Dose-limiting Toxicity0 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Dose-limiting Toxicity0 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Dose-limiting Toxicity0 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Dose-limiting Toxicity0 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Dose-limiting Toxicity0 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Dose-limiting Toxicity1 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Dose-limiting Toxicity0 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Dose-limiting Toxicity0 Participants
Comparison: Because only 1 participant experienced a DLT (Grade 3 cytokine release syndrome in Arm 1 Cohort 6), no MTD could be reached.
Secondary

Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)

Appropriate imaging of the SYNB1891-injected tumor(s) and up to 5 target (noninjected) lesions was performed at baseline and every 2 cycles during the treatment period. Tumor response was assessed by the local investigator using RECIST 1.1 (Eisenhauer et al 2009). Per RECIST 1.1, target lesions are categorized as follows: complete response (CR): disappearance of all target lesions (no evaluable disease); partial response (PR): ≥ 30% decrease in the sum of the longest diameter of target lesions; progressive disease (PD): ≥ 20% increase in the sum of the longest diameter of target lesions; stable disease (SD): small changes that do not meet above criteria.

Time frame: Up to 13 months

Population: All participants who received study drug and had an on-treatment response assessment (including Not Evaluable) or who discontinued study before any response assessment was performed due to disease progression.

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD1 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD1 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD1 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD1 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD1 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD3 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD1 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD3 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD1 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD2 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD1 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD2 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD3 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD1 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)SD2 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Best Tumor Response as Measured by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1)PD1 Participants
Secondary

Number of Participants With Treatment-Emergent Adverse Events

Toxicity was graded in accordance with the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE), version 5.0, as follows: Grade 1 (mild/asymptomatic; no intervention); Grade 2 (moderate; minimal intervention); Grade 3 (severe/medically significant; hospitalization indicated; disabling); Grade 4 (life-threatening; urgent intervention required); or Grade 5 (fatal). Adverse events (AEs) were reported from clinical laboratory tests, vital sign and weight measurements, physical examinations, and any other medically indicated assessments, including participant interviews, from the time informed consent was signed through the end of the safety follow-up period. AEs were considered to be treatment-emergent adverse events (TEAEs) if they occurred or worsened in severity after the first dose of study treatment. TEAEs were considered treatment-related if the relationship to study drug was possibly, probably, or definitely related.

Time frame: Up to 13 months

Population: All participants who were enrolled, allocated to treatment, and received at least 1 dose of investigational product.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab0 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 31 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18913 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 51 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal0 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 10 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 21 Participants
Arm 1 Cohort 1: SYNB1891 Monotherapy (1 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsAny TEAE3 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 21 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsAny TEAE3 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 30 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab0 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal0 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 11 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 51 Participants
Arm 1 Cohort 2: SYNB1891 Monotherapy (3 × 10^6 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18911 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 21 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 50 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal0 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 12 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsAny TEAE4 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab0 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 31 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18912 Participants
Arm 1 Cohort 3: SYNB1891 Monotherapy (1 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 33 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 21 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab0 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 11 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal0 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18913 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsAny TEAE5 Participants
Arm 1 Cohort 4: SYNB1891 Monotherapy (3 × 10^7 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 50 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsAny TEAE3 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 11 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 21 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 31 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 50 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18913 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab0 Participants
Arm 1 Cohort 5: SYNB1891 Monotherapy (1 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal0 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 10 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsAny TEAE6 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18916 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 23 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 33 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal1 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab0 Participants
Arm 1 Cohort 6: SYNB1891 Monotherapy (3 × 10^8 Live Cells)Number of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 50 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab0 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsAny TEAE4 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18912 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 30 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 23 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 11 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal0 Participants
Arm 2 Cohort 1: SYNB1891 (1 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 50 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsTEAE leading to treatment withdrawal0 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 51 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 31 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 21 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsTEAE related to SYNB18912 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 11 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsTEAE related to atezolizumab2 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsAny TEAE4 Participants
Arm 2 Cohort 2: SYNB1891 (3 × 10^7 Live Cells) + AtezolizumabNumber of Participants With Treatment-Emergent Adverse EventsMaximum TEAE severity Grade 40 Participants

Source: ClinicalTrials.gov · Data processed: Feb 15, 2026