The primary purpose of this study was to determine the optimal dose of ASP5354 for ureter visualization in participants undergoing laparoscopic/minimally invasive colorectal surgery This study also investigated the safety, tolerability and the pharmacokinetics of ASP5354 in participants undergoing laparoscopic/minimally invasive colorectal surgery.

Participants were randomly assigned at each dose level (dose A, B, C). During a standard minimally invasive surgery, visualization of the surgical field was assessed following the placement of the near infrared fluorescence (NIR F) imaging system proximal to the ureter of interest and then ASP5354 was administered.

Based on Visualization Review Committee (VRC) review of the initial 3 dose levels, if none of the doses selected had visualization, then additional two dose levels (dose D and E) was planned to be added; if 1 dose selected has visualization, then the dose level D was planned to be added. The dose level F was planned to be added if only the dose E level has visualization.

Inclusion Criteria:

• Subject is scheduled to undergo laparoscopic/minimally invasive colorectal surgery.

• Subject will need visualization of the ureter(s).

• Female subject is not pregnant and at least 1 of the following conditions apply:

  • Not a woman of childbearing potential (WOCBP)
  • WOCBP who agrees to follow the contraceptive guidance from the time of informed consent through at least 30 days after final study treatment administration.

• Female subject must agree not to breastfeed starting at screening and throughout the study period.

• Female subject must not donate ova starting at first dose of investigational product (IP) and throughout the study period and for 30 days after final study treatment administration.

• Male subject with female partner(s) of childbearing potential (including breastfeeding partner) must agree to use contraception throughout the treatment period and for 30 days after final study treatment administration.

• Male subject must not donate sperm during the treatment period and for 30 days after final study treatment administration.

• Male subject with pregnant partner(s) must agree to remain abstinent or use a condom for the duration of the pregnancy throughout the study period and for 30 days after final study treatment administration.

• Subject agrees not to participate in another interventional study while participating in the present study.

• Subjects enrolled after optimal dose determination:

Subject has any of the following values at screening:

• Body mass index > 25
• Estimated glomerular filtration rate (eGFR) ≥ 15 mL/min/1.73 m^2 and < 60. Subjects with an eGFR ≥ 60 mL/min/1.73 m^2 may be considered after discussion with the medical monitor.

Exclusion Criteria:

• Subject is anticipated to require ureteral stenting during surgery.

• Subject has a history of known retroperitoneal fibrosis.

• Subject has an active urinary tract infection.

• Subject has received any investigational therapy within 28 days or 5 half-lives, whichever is longer, prior to screening.

• Subject has any condition that makes the subject unsuitable for study participation.

• Subject has a known or suspected hypersensitivity to ASP5354, indocyanine green (ICG) or any components of the formulation used.

• Subject has had previous exposure to ASP5354.

• Subject has moderate to severe cardiac disease that limits daily functioning (New York Heart Association Class III-IV) or other medical conditions that the investigator feels would impact safety or study compliance.

• Subject has a mean resting heart rate ≤ 45 bpm or ≥ 115 bpm, mean systolic blood pressure (SBP) ≥ 160 mmHg or mean diastolic blood pressure (DBP) ≥ 100 mmHg on day -1. If the mean blood pressure exceeds the limits above, repeat readings can be taken. Subject who has adequately controlled blood pressure is eligible.

• Subject has a mean corrected QT interval (Triplicate electrocardiogram [ECG]) using Fridericia's formula (QTcF) > 430 msec (for male subjects) and > 450 msec (for female subjects) on day -1. If the mean QTcF exceeds the limits above, the mean of 1 additional triplicate ECG may be taken.

• Subject has any of the following screening laboratory values:

  • Hemoglobin ≤ 9 g/dL
  • Absolute neutrophil count ≤ 1500/µL
  • Platelet count ≤ 100000/µL
  • eGFR < 60 mL/min/1.73 m^2 (Not applicable to subjects enrolled after optimal dose determination.)
  • Serum bilirubin ≥ 2 × upper limit of normal (ULN)
  • Aspartate aminotransferase (AST) or serum glutamic oxaloacetic transaminase ≥ 2.5 × ULN
  • Alanine aminotransferase (ALT) or serum glutamic pyruvic transaminase ≥ 2.5 × ULN

• Subject has taken ICG or other near-infrared fluorescence (NIR)-F imaging agents within 48 hours prior to study treatment administration.

• Subject has taken diuretics or inhibitors of renal transporters defined by Food and Drug Administration (FDA) within 48 hours prior to study treatment administration.

• Subject has used any illicit drugs, unless legally prescribed and is not being abused (amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine and opiates) within 1 month prior to day -1.

• Subject has a history of alcohol abuse. Subject should not have consumed any alcohol within 48 hours of surgery.

Access to anonymized individual participant level data will not be provided for this trial. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.