On October 18, 2025 Delcath Systems, Inc. (NASDAQ: DCTH), an interventional oncology company focused on the treatment of primary and metastatic liver cancers, reported the results of the CHOPIN randomized Phase 2 clinical trial (CHOPIN Trial) presented by Principal Investigator and Lead Author Professor Ellen Kapiteijn, MD, from Leiden University Medical Center’s Department of Medical Oncology at the 2025 European Society of Medical Oncology (ESMO) (Free ESMO Whitepaper) Annual Congress.
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CHOPIN Trial Design
The investigator-initiated, prospective, randomized Phase 2 CHOPIN Trial was designed to compare the safety, tolerability, and efficacy of Delcath’s CHEMOSAT Hepatic Delivery System (HDS) with melphalan for percutaneous hepatic perfusion (PHP) when used alone versus when combined with the systemic immune checkpoint inhibitors (ICI) ipilimumab and nivolumab. Patients with metastatic uveal melanoma (mUM) were randomized 1:1 to receive PHP alone or in combination with ipilimumab and nivolumab. CHEMOSAT is the device component of the U.S. Food and Drug Administration (FDA) approved combination drug and device product HEPZATO KIT (HEPZATO (melphalan) for Injection/Hepatic Delivery System). HEPZATO KIT is approved for the liver-directed treatment of adult patients with uveal melanoma with unresectable hepatic metastases with less than 50% liver involvement and is administered every six to eight weeks for up to six melphalan/HDS treatments.
Ipilimumab and nivolumab are approved by the FDA and European Union for the treatment of unresectable metastatic melanoma, typically administered intravenously every three weeks for four doses, followed by maintenance nivolumab monotherapy every two to four weeks until disease progression.
The CHOPIN Trial randomized 76 patients 1:1 to receive PHP alone at weeks one and seven (PHP group) or four cycles of ipilimumab (1 mg/kg) and nivolumab (3 mg/kg) every three weeks over approximately nine weeks with two PHP treatments at weeks one and seven (combination group). The CHOPIN Trial design did not include additional PHP treatments beyond two treatments or nivolumab maintenance monotherapy. Once the nine-week treatment period was completed patients were monitored until progression. Key eligibility criteria included unresectable hepatic metastases with 50% or less unresectable disease and limited extrahepatic disease. The primary endpoint was one-year progression-free survival; secondary endpoints included safety, best overall response rate, overall survival, and hepatic progression-free survival.
CHOPIN Trial Results
Key Results from the CHOPIN Phase 2 Trial:
Progression-Free Survival (95% CI):
One Year % (95% CI)
Combination group: 54.7% (36.8 – 69.5)
PHP group: 15.8% (5.8 – 30.1)
Median months (95% CI)
Combination group: 12.8 (9.2 – 15.4)
PHP group: 8.3 (6.0 – 9.6)
Hazard Ratio 0.34 (0.19 – 0.60)
P<0.001
Overall Survival – (95% CI):
One Year % (95% CI)
Combination group: 82.8% (65.6 – 91.9)
PHP group: 82.2% (64.5 – 91.6)
Two Year % (95% CI)
Combination group: 49.6% (29.3 – 67.0)
PHP group: 22.1% (7.9 – 40.6)
Median: months (95% CI)
Combination group: 23.1 (20.2 – 38.5)
PHP group: 19.6 (15.2 – 21.8)
Hazard Ratio: 0.39 (0.20 – 0.77)
P = 0.006
Best Overall Response Rate (95% CI):
Combination group: 76.3 (59.4 – 88.0)
PHP group: 39.5 (24.5 – 56.5)
P < 0.001
Grade 3 or higher treatment-related adverse events were more frequent in the combination group (81.6% vs. 40.5%, P<0.001), but most were manageable with standard care. Overall, the combination treatment was well tolerated, with types, rates and frequencies of adverse events consistent with individual use of PHP and checkpoint inhibitors. No new safety signals were identified.
The abstract is available at ESMO (Free ESMO Whitepaper) Congress 2025 – Mini Oral Session LBA59.
"The CHOPIN trial clearly demonstrates that adding ipilimumab and nivolumab to PHP is both effective and tolerable. The efficacy results are impressive, especially when considering the treatment regime included only two PHP treatments and did not include nivolumab maintenance. Since many oncologists start systemic therapy first, this approach provides valuable lead time for patient assessment and scheduling PHP, helping to overcome logistical barriers and support broader adoption and near- to medium-term uptake," said Gerard Michel, Chief Executive Officer of Delcath Systems.
A number of large, randomized clinical trials shows that patients with liver metastases typically have poorer outcomes than those with metastases elsewhere when treated with ICIs across multiple tumor types, including melanoma, non-small-cell lung cancer (NSCLC), urothelial carcinoma, and renal cell carcinoma1, 2. This diminished efficacy of ICIs has been attributed to the well-documented immunosuppressive nature of the liver microenvironment, with underlying mechanisms increasingly understood through preclinical and clinical research3.
"In addition to the potential immediate benefit to patients with metastatic uveal melanoma, the possible synergy of PHP and ICI therapy seen in the successful Phase 2 CHOPIN trial may be transferable to other cancers with liver-dominant disease, and Delcath looks forward to investigating that potential," said Dr. Vojislav Vukovic, Chief Medical Officer of Delcath Systems.
Conference Call Information
Delcath Systems, Inc. will host a conference call and webcast on October 20, 2025, at 8:45 a.m. Eastern Time to discuss the Phase 2 CHOPIN Trial results and provide a brief overview of the financial results and guidance announced in this release. Joining Delcath management on the call with pre-recorded remarks will be Dr. Vincent T. Ma, Assistant Professor and Medical Oncologist at the University of Wisconsin Department of Medicine, a current user of HEPZATO KIT for the treatment of metastatic uveal melanoma patients, an expert in treating cutaneous melanoma, and a co-author on the seminal Nature Medicine paper exploring liver immune tolerance mechanisms in cancer.
To participate in this event, dial in approximately 5 to 10 minutes before the beginning of the call.
Event Date: Monday, October 20
Time: 8:45 AM Eastern Time
Participant Numbers:
Toll Free: 1-877-407-3982
International: 1-201-493-6780
Webcast: View Source;tp_key=6f3953dd75
A replay of the webinar will be available shortly after the conclusion of the call and will be archived on the company’s website View Source
(Press release, Delcath Systems, OCT 18, 2025, View Source [SID1234656766])