Ewingella americana is an ordinary environmental bacterium studied as a living cancer treatment administered intravenously. One Japanese laboratory reported that a frog-gut strain settled inside tumors in mice and cleared them. Nothing has been measured in a person. The organism's own clinical history is scattered infections in already-weakened patients, one of them fatal. The strain cannot be obtained. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Blood culture, aerobic and anaerobic | No established target — track clearance to no growth | Bacteria persisting in the blood were a dose-limiting toxicity in the attenuated-Salmonella trial |
| Absolute neutrophil count | 1.5–8.0 × 10⁹/L | Low counts mark the patients in whom this organism has caused invasive infection, and it is the cell population that rose most after dosing |
| Platelet count | 150–400 × 10⁹/L | Thrombocytopenia was among the dose-limiting toxicities of intravenous attenuated Salmonella |
| C-reactive protein | Below 5 mg/L | The inflammatory response is the intended immune arm, so a rise is expected rather than alarming |
| Procalcitonin | Below 0.1 ng/mL | Separates an intended inflammatory response from bacterial sepsis |
| Alanine aminotransferase | 7–55 U/L | The mouse study screened liver chemistry for organ toxicity and found none, so a rise would be a new signal |
| Serum creatinine with estimated filtration rate | Creatinine 0.6–1.3 mg/dL; filtration rate above 60 mL/min/1.73 m² | Peritoneal infection during dialysis for kidney failure is among this organism's most frequently reported human infections |
| Serum ferritin with transferrin saturation | Ferritin 30–300 ng/mL in men, 15–200 ng/mL in women; transferrin saturation 20–50% | Iron overload is an exclusion in the one intravenous trial, and bacterial growth inside the tumor depends on usable iron |
| Tumor burden on imaging | No established target — track change from the individual's own baseline measurements | This is the efficacy endpoint |
Cadence: Safety baseline before any dose; blood cultures and chemistry at 24, 48 and 72 hours; inflammatory markers daily for the first 72 hours; then at 1 week, 4 weeks, and every 3 months while tumor response is followed; imaging at baseline and 6–8 weeks.