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Pudexacianinium — ASP-5354

Pudexacianinium chloride (ASP5354) remains an investigational NIR fluorophore for ureteral visualization. Astellas' April 2026 pipeline lists phase III, and a 2026 primary pharmacokinetic paper describes phase III studies completed in 2025. An FDA approval or US prescribing label was not identified in this review.[1][2][3]

Mechanism and intended role​

Unlike IV ICG, which is predominantly hepatically cleared, pudexacianinium is excreted largely unchanged through the kidneys, primarily by glomerular filtration. It can therefore highlight the urinary ureteral lumen after IV administration, giving a luminal signal that IV ICG does not provide. The goal is ureteral identification without cystoscopic catheter placement or retrograde instillation, an approach studied in laparoscopic colorectal surgery; its performance in sacrocolpopexy, hysterectomy, deep endometriosis, and reoperative or irradiated fields remains unestablished.[2][4]

Compared with the alternatives: indigo carmine is a visible dye whose local availability should be checked; methylene blue is a visible dye that has also produced NIR ureter images in a 12-patient open-surgery feasibility study using Mini-FLARE after ureter exposure[8]; retrograde ICG works but needs a cystoscopic step. Pudexacianinium combined IV administration with NIR imaging on the Stryker 1688 AIM platform in phase II; compatibility with other NIR systems requires device-specific validation. In the 12-patient phase II colorectal study, 1 mg and 3 mg IV yielded visualization at both 30 minutes and the end of surgery in 5/6 and 3/3 participants, respectively.[4]

Human evidence​

Albert 2023: a randomized dose-ranging phase II study enrolled 12 adults undergoing laparoscopic colorectal surgery; the protocol excluded known retroperitoneal fibrosis, active urinary tract infection, anticipated ureteral stenting, and hypersensitivity to pudexacianinium or ICG. Successful visualization at 30 minutes and the end of surgery occurred in 2/3 at 0.3 mg, 5/6 at 1 mg and 3/3 at 3 mg. One drug-related grade-1 proteinuria event occurred; two serious events were not attributed to the drug. Median surgeon-rated intensity rose with dose (mild at 0.3 mg, moderate at 1 mg, strong at 3 mg), and the mean fraction excreted into urine during surgery was 22%, 16% and 40% at the three doses.[4]

Conspicuity rating: in a 2025 reliability study using phase II images, 17 surgeons rated ureter conspicuity on a 5-point Likert scale. Mean ratings were about 3.8 with NIR fluorescence versus 2.3 with white light, with inter-rater ICC 0.70 and intra-rater ICC 0.82. The study measured inter-rater and one-week test–retest reliability of surgeon image ratings.[5]

Phase III: NCT05754333 enrolled 107 participants and completed in January 2025. Sponsor-posted final registry results report that, in 72 adults with normal or mildly impaired renal function assigned 3 mg IV, mean investigator-rated ureter conspicuity at 30 minutes was 4.3 with NIR versus 2.7 with white light (paired difference 1.5 points, 95% CI 1.2–1.9). NCT05999747 enrolled 95 participants, including adults with kidney disease, and completed in October 2025.[6][7]

Renal pharmacokinetics, 2026: a 28-participant phase I study used a single 3 mg IV study dose (mild, moderate and severe impairment, 6 each; 10 with normal function). Exposure rose with renal impairment: AUC ratios versus matched normal function were 1.53, 2.30 and 3.69 for mild, moderate and severe impairment, with peak concentration similar across groups. In vitro it was not a substrate of the renal transporters tested.[2]

Administration and limitations​

  • Research protocols govern dose, administration, eligibility and redosing. There is no verified US manufacturer prescribing regimen to recommend here.
  • Renal function affects exposure and urinary delivery. In the six enrolled participants with severe renal impairment, one was excluded from the pharmacokinetic analysis for suspected extravascular administration. In the analyzed group, mean 48-hour urinary recovery was 64%; it rose to about 80% in an exploratory calculation excluding a different participant with unexplained low plasma and urine concentrations. Other renal-function groups had approximately 90% or more recovery. No clinical CKD dose rule has been established.[2]
  • Camera compatibility must be established for the specific device or protocol. NIR capability or the presence of Firefly, SPY or Rubina does not automatically establish compatibility or authorization for every fluorophore.
  • No routine price, formulary access or same-case sequencing with ICG is established here.
  • Large comparative studies with meaningful injury and patient outcomes are needed before calling this a standard of care.
AgentMain distinction
ICGIV perfusion imaging; direct urinary instillation is off-label
Indigo carmineBLUDIGO is a currently labeled IV aid for cystoscopic ureteral assessment
Methylene blueVisible dye; surgical applications are off-label and have important systemic safety concerns
Sodium fluoresceinOff-label urinary-efflux dye; ophthalmic indication is separately labeled

References​

1. Astellas Pharma. FY2025 supplementary documents; Rx+ pipeline as of April 2026, p21. Pipeline.

2. Kojima T, Saito M, Matsuda T, et al. "Effects of renal impairment on the pharmacokinetics, safety, and tolerability of pudexacianinium (ASP5354) after IV administration: a mechanistic exploration." Eur J Clin Pharmacol. 2026;82(5):131. doi:10.1007/s00228-026-04063-1

3. FDA Substance Registration System. Pudexacianinium chloride; UNII D23R36L5QY. Record and approval-status caveat.

4. Albert M, Delgado-Herrera L, Paruch J, et al. Pudexacianinium (ASP5354) chloride for ureter visualization in participants undergoing laparoscopic, minimally invasive colorectal surgery. Surg Endosc. 2023;37(9):7336–7347. doi:10.1007/s00464-023-10193-9.

5. Atzinger C, Dickerson H, Polek E, et al. Reliability of Likert Scale for Surgeon-Rated Conspicuity of Ureters with Pudexacianinium Chloride (ASP5354). JSLS. 2025;29(3):e2024.00069. doi:10.4293/JSLS.2024.00069

6. ClinicalTrials.gov. NCT05754333 and NCT05999747: ASP5354 ureter visualization studies. NCT05754333; NCT05999747.

7. EU Clinical Trials Register. NCT05754333 (EudraCT 2025-000122-33): final results, version 2, published November 15, 2025. Results.

8. Verbeek FPR, van der Vorst JR, Schaafsma BE, et al. "Intraoperative near infrared fluorescence guided identification of the ureters using low dose methylene blue: a first in human experience." J Urol. 2013;190(2):574–579. doi:10.1016/j.juro.2013.02.3187