OPT-IN (EA2197) Clinical Trial Overview

The OPT-IN (EA2197) clinical trial, led by ECOG-ACRIN with NCI support, is a Phase II/III randomized study evaluating whether preoperative and postoperative gemcitabine and cisplatin combination chemotherapy improves overall survival (OS) compared to postoperative adjuvant chemotherapy alone in patients with incidentally detected (incidental) T2-T3 stage gallbladder cancer during cholecystectomy. Emory University's Professor Shishir Maithel serves as the principal investigator (PI), and the study is conducted at multiple centers across the United States. Patient enrollment is currently closed, and the study is in the stage of awaiting OS data maturity.

Treatment Protocol Design

The control arm (Arm I) involves administering gemcitabine and cisplatin in a 21-day cycle for up to 8 cycles within 16 weeks after cholecystectomy and lymph node dissection. The experimental arm (Arm II) administers the same regimen for 4 cycles before surgery, followed by an additional 4 cycles, resulting in the same total treatment burden while evaluating the neoadjuvant effect. Both drugs are generic versions with expired patents, making them cost-effective. A positive outcome could lead to their immediate adoption in global clinical practice.

ASCO 2025 Similar Trial Results

The GAIN Trial (Phase III, PI: Thorsten Goetze, Frankfurt University), presented at ASCO 2025, used a similar design in resectable cholangiocarcinoma and demonstrated that the neoadjuvant gemcitabine and cisplatin arm nearly doubled the median OS to 27.8 months versus 14.6 months and significantly improved the R0 resection rate to 62.5% versus 33.3%. However, the trial was terminated early due to a small sample size of 68 patients, limiting its significance to a 'signal-generating' level. At the same conference, POLCAGB (Phase III) also presented results indicating that neoadjuvant chemoradiotherapy significantly improved OS and resection rates compared to chemotherapy alone in locally advanced gallbladder cancer, further supporting the rationale for preoperative treatment interventions.

Competitive Landscape and Changes in Standard of Care

The current standard of care for first-line treatment of advanced cholangiocarcinoma is the combination of AstraZeneca's (AZN) Imfinzi (durvalumab) and gemcitabine/cisplatin (TOPAZ-1, FDA approved in September 2022, HR 0.80) and Merck's (MRK) Keytruda (pembrolizumab) and gemcitabine/cisplatin (KEYNOTE-966, FDA approved in October 2023, HR 0.83), establishing the use of immune checkpoint inhibitors. In November 2024, Jazz Pharmaceuticals (JAZZ) received accelerated approval for Ziihera (zanidatamab) as a second-line treatment for HER2-positive cholangiocarcinoma (ORR 52%). OPT-IN targets a separate segment of resectable early-stage gallbladder cancer and is therefore more complementary than directly competitive with these advanced-stage drugs, potentially leading to a new sequential treatment paradigm of preoperative chemotherapy → surgery → immune combination therapy if the results are positive.

Market and Patient Impact

The gallbladder cancer therapeutics market is projected to grow from approximately USD 329 million in 2025 to USD 513 million in 2034 (CAGR of 5.8%), and the overall cholangiocarcinoma market is approximately USD 3.86 billion in 2025. A major barrier to market expansion for gallbladder cancer is the late stage at diagnosis, resulting in a low rate of resectability. If OPT-IN yields positive results, neoadjuvant chemotherapy could increase the number of patients eligible for resection, leading to an increase in surgical procedures → increased use of adjuvant therapy → and facilitating subsequent immune combination therapy trials, creating a virtuous cycle. This could create new demand not only for generic chemotherapy drug suppliers but also for medical device companies specializing in surgical equipment and techniques.