Researchers will compare people who get the ACC Set plus standard of care to people who get standard of care alone. This will show whether adding the ACC Set helps.

Participants will:

Join one of two groups, chosen by chance: the ACC Set plus standard of care, or standard of care alone.

Have the cooling tube in place for up to 3 days, if they are in the ACC Set group.

Have blood tests and pain checks every few hours during their hospital stay. Return for follow-up visits about 7, 14, and 30 days later.

CHILL-AP is a prospective, multicenter, randomized controlled trial evaluating the safety and effectiveness of the Arctx Cool Catheter (ACC) Set in patients hospitalized with acute pancreatitis (AP). The study is designed to support a marketing submission to the U.S. Food and Drug Administration (FDA).

Background and rationale: There are currently no FDA-approved therapies for AP; care is supportive and consists of fluid replacement, nutrition support, and pain control. In AP, the body's inflammatory response can become severe and progress to systemic inflammatory response syndrome (SIRS) and organ failure. Laboratory and early clinical evidence suggests that cooling the pancreas can calm this early inflammation, regardless of what caused the AP. The ACC Set is intended to cool the pancreas locally, without cooling the whole body, in order to reduce the severity of AP and shorten the time it takes to recover.

Investigational device: The ACC Set is made up of the Arctx Catheter and an Arctx Extension Line that connects the catheter to a Blanketrol III Hyper-Hypothermia System. The Arctx Catheter is a single-use, non-implantable tube with several channels, placed in the stomach/duodenum. Two channels circulate the cooling fluid through the connected heat exchanger; a third channel allows fluids to be given or drained through the gut.

Design and randomization: Eligible participants are randomized 1:1, stratified by site, to receive either the ACC Set plus standard of care or standard of care alone. The study may enroll up to 200 participants (approximately 100 per arm) at up to 25 sites in the United States and 1 in Latin America, with at least 50% of participants enrolled at U.S. sites and no single site enrolling more than 20% of total enrollment. Bias is minimized through randomization, objective eligibility criteria, uniform effectiveness criteria, an independent blinded image reviewer, and oversight by an independent Data Monitoring Committee (DMC).

Intervention: For participants randomized to the device arm, ACC placement and the start of cooling must occur within a total of 48 hours of symptom onset. Eligibility is reconfirmed immediately before placement. The device may remain in place for up to 72 hours, with earlier removal at the investigator's discretion; if a device is removed and replaced, the total time in use may not exceed 72 hours. An x-ray taken after placement confirms the position. Body temperature and gut (catheter) temperature are monitored during cooling. The gut is examined with an endoscope when there is a clinical reason to do so.

Standard of care and nutrition: Initial management in both arms follows American Gastroenterological Association Institute guidance, with medications given per each institution's standard of care. To support consistent assessment of the primary endpoint, feeding and the measurement of food tolerance are standardized across sites and across both arms. Standardized oral nutrition of at least 500 calories is offered, and the percentage of calories eaten, abdominal pain, and any vomiting are recorded around each feeding.

Assessments and follow-up: After randomization, nutrition intake is assessed about every 6 hours with standard mealtimes, and blood tests (CBC, CMP including amylase and lipase, and C-reactive protein) along with PASS and mPASS scoring are obtained about every 12 hours, each continuing until the participant can tolerate oral food without organ failure or SIRS. A contrast-enhanced CT is obtained at baseline and at Day 14.

Follow-up visits occur at Day 7, Day 14, and Day 30, with the Day 30 visit occurring 30 days after hospital discharge. An independent radiologist experienced in AP reviews the baseline and Day 14 contrast-enhanced CTs.

Statistical considerations: The primary effectiveness analysis is performed on the intent-to-treat (ITT) population, with sensitivity analyses on the modified ITT and per-protocol populations; safety is analyzed on all treated participants. The effectiveness sample size of 188 participants (94 per group) provides 80% power at a one-sided alpha of 0.025 to detect the expected difference in time to oral food tolerance, assuming a 5% dropout rate; the total of 200 participants also meets the goal of about 100 participants in the treatment arm for safety.

Inclusion Criteria:

• Meets criteria for SIRS, defined as meeting two of the following four criteria:
• Temperature >38°C (100.4°F) or <36°C (96.8°F)
• Heart rate >90 beats per minute
• Respiratory rate >20 breaths per minute or PaCO2 <32 mmHg
• White blood cell (WBC) count >12,000/mm³ or <4,000/mm³, or >10% immature (band) forms
• Symptom onset within a window of time enabling ACC placement within a total of 48 hours
• Diagnosis of acute pancreatitis by all three of the following criteria at the time of presentation (not referred), significant enough to require hospitalization:
• Abdominal pain consistent with acute pancreatitis (acute onset of persistent, severe, epigastric pain, often radiating to the back)
• Serum amylase and/or lipase greater than 3 times the upper limit of normal
• Characteristic findings on contrast-enhanced CT (CECT). Note: If CT is not standard of care, it will be performed after the patient signs informed consent and all other eligibility criteria are met.
• Signed written informed consent, and willingness and ability to complete follow-up requirements

Exclusion Criteria:

• Serum creatinine >1.5 mg/dL
• Current treatment with pancreatic enzyme replacement therapy
• Current treatment with hemodialysis or peritoneal dialysis
• Active malignancy: a history of any invasive malignancy (except nonmelanoma skin cancer), unless treated with curative intent with no clinical signs or symptoms of the malignancy for at least five years
• Pancreatic calcifications identified by the baseline contrast-enhanced CT (CECT)
• History or evidence of pancreatic surgery
• Uncorrected coagulation abnormalities or currently taking anti-coagulation medication
• Known history of chronic pancreatitis
• Prior history of acute pancreatitis requiring endoscopic drainage procedures and/or necrosectomy
• Recurrent acute pancreatitis within 30 days
• Known esophageal deformity or esophageal trauma, or known ingestion of acidic or caustic poisons
• Recent trans-nasal surgery, severe maxillofacial trauma, or known diseases of the sinus tract
• Nasopharyngeal or esophageal obstruction, diverticula, or stricture
• Septal deviations
• Known esophageal or gastric varices
• History of esophageal, gastric, or duodenal surgery, specifically including gastric bypass
• Reduced platelet count below 50,000
• Less than 40 kg of body mass
• Known allergy to any device component (polyurethane, barium sulphate, polyvinyl chloride, polycarbonate, nylon, ABS, polyethylene)
• Female who is pregnant or nursing
• Participated in another investigational drug or therapeutic medical device study within 30 days before randomization
• Any history of congestive heart failure
• History of peptic ulcer disease and/or H. pylori within the past year
• Glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m² (GFR <30)
• Known or suspected diabetic nephropathy
• Body mass index ≥40 kg/m², or BMI ≥35 kg/m² with significant comorbidity
• Currently using GLP-1 receptor agonists (RAs)

The sponsor does not plan to share individual participant data (IPD). The data generated in this study are confidential and proprietary to the sponsor and will be used to support a regulatory submission to the U.S. Food and Drug Administration.