The drug is called Kimmtrak, and it represents one of the more unusual crossovers in modern oncology. Approved by the FDA on January 25, 2022, tebentafusp — sold under the brand name Kimmtrak — became the first systemic therapy ever to demonstrate a survival benefit for patients with unresectable or metastatic uveal melanoma, a rare cancer that originates in the eye. What makes this drug particularly notable is that it treats a cancer most people have never heard of, one that starts in the pigmented cells of the eye and, in roughly half of all cases, spreads to the liver with devastating consequences. Before Kimmtrak’s approval, doctors treating metastatic uveal melanoma had essentially no systemic therapy proven to extend life.
Patients faced a grim landscape of off-label treatments borrowed from skin melanoma protocols, none of which had demonstrated meaningful overall survival improvements in clinical trials. Kimmtrak changed that, though at a staggering cost — roughly $400,000 to $500,000 per year of treatment — and with a mechanism of action unlike most cancer drugs on the market. It is a bispecific T-cell engager, meaning one end of the molecule grabs onto a protein on melanoma cells while the other end recruits the patient’s own immune cells to destroy them. This article covers how Kimmtrak works and who qualifies for it, the emergence of a second FDA-approved option called Hepzato Kit that delivers chemotherapy directly to the liver, and a promising pipeline drug called darovasertib that may soon offer a third path forward. For families dealing with dementia and cognitive decline, understanding rare cancers like uveal melanoma matters more than you might think — older adults are disproportionately affected, and the intersection of complex medical decision-making with cognitive impairment creates real challenges for caregivers.
Table of Contents
- What Is the Rare Eye Drug Used for Metastatic Cancer, and How Does It Work?
- Understanding Uveal Melanoma and Why It Spreads to the Liver
- Hepzato Kit — A Second FDA-Approved Option That Targets the Liver Directly
- Darovasertib — The Pipeline Drug That Could Change Treatment for HLA-Negative Patients
- Side Effects, Cost, and the Practical Realities of Treatment
- The Neoadjuvant Promise — Treating the Eye Tumor Before It Spreads
- Where Uveal Melanoma Treatment Is Headed in 2026 and Beyond
- Conclusion
- Frequently Asked Questions
What Is the Rare Eye Drug Used for Metastatic Cancer, and How Does It Work?
Kimmtrak (tebentafusp) is manufactured by Immunocore Holdings and belongs to a class of immunotherapy drugs called bispecific T-cell engagers, or TCEs. The “bispecific” part is key: one arm of the molecule is engineered to recognize gp100, a protein found on the surface of uveal melanoma cells, while the other arm latches onto T cells — the immune system’s natural killers. By physically bridging the cancer cell and the T cell, Kimmtrak essentially forces an immune response that the body would not mount on its own. this mechanism is distinct from checkpoint inhibitors like pembrolizumab or nivolumab, which work by removing the brakes on the immune system rather than actively directing T cells to a specific target. The clinical evidence supporting Kimmtrak comes primarily from the Phase 3 trial that led to its FDA approval, with updated data published in the new England Journal of Medicine in 2023. The three-year survival numbers tell the story clearly: median overall survival was 21.6 months for patients receiving tebentafusp compared to 16.9 months in the control group, and 27% of tebentafusp patients were alive at three years versus 18% in the control arm.
Those numbers may sound modest in absolute terms, but for a disease that had no proven systemic treatment, they represent a genuine shift. Kimmtrak generated $400.0 million in revenue for the full year of 2025, reflecting 29% year-over-year growth and 15 consecutive quarters of increasing sales — a sign that oncologists are prescribing it with growing confidence. There is, however, a significant limitation. Kimmtrak only works in patients who carry a specific immune marker called HLA-A*02:01, which is found in roughly 40-50% of people of European descent and at lower rates in other populations. If you do not carry this marker, Kimmtrak is not an option, which immediately narrows the eligible patient pool. This genetic prerequisite is one of the reasons researchers have been pushing hard to develop alternative treatments that work regardless of HLA status.
Understanding Uveal Melanoma and Why It Spreads to the Liver
Uveal melanoma is the most common primary cancer of the eye in adults, but “common” is relative — only about 2,500 new cases are diagnosed each year in the United States. The cancer arises in the uveal tract, the pigmented middle layer of the eye that includes the iris, ciliary body, and choroid. Most uveal melanomas develop in the choroid, the vascular layer at the back of the eye, which means they can grow silently for months or even years before being detected during a routine eye exam. Unlike skin melanoma, which is strongly associated with UV exposure, uveal melanoma’s relationship to sunlight is far less clear, and its molecular biology is fundamentally different. The real danger of uveal melanoma is its tendency to metastasize. Approximately 50% of patients will eventually develop metastatic disease, and the liver is the primary site of spread in the vast majority of those cases.
This liver tropism is not random — uveal melanoma cells appear to have a biological affinity for the hepatic microenvironment. Once the cancer reaches the liver, outcomes deteriorate rapidly. Historical median survival for metastatic uveal melanoma was roughly 12 months, and standard chemotherapy and immunotherapy regimens that work for cutaneous melanoma have been largely ineffective. For caregivers of older adults with cognitive decline, a diagnosis of uveal melanoma in their loved one introduces layers of complexity. The initial eye cancer may be treated with radiation or surgery, and the patient may seem fine for years before metastatic disease appears. However, if the patient has developed dementia or significant cognitive impairment in the interim, they may not be able to participate meaningfully in treatment decisions, report symptoms accurately, or tolerate the frequent monitoring that metastatic disease requires. Advance care planning becomes critical well before a crisis point.
Hepzato Kit — A Second FDA-Approved Option That Targets the Liver Directly
On August 14, 2023, the FDA approved a second treatment for metastatic uveal melanoma: the Hepzato Kit, a melphalan hepatic delivery system manufactured by Delcath Systems. Unlike Kimmtrak, which is a systemic immunotherapy given intravenously, Hepzato Kit takes a radically different approach. It delivers high-dose melphalan chemotherapy directly to the liver through a procedure called percutaneous hepatic perfusion, or PHP. During the procedure, the liver’s blood supply is temporarily isolated from the rest of the body using balloon catheters and a filtration system, allowing oncologists to flood the organ with a chemotherapy dose that would be toxic if it circulated systemically. The results from the FOCUS Phase 3 trial showed a 36.3% objective response rate, including a 7.7% complete response rate and 28.6% partial response rate.
These numbers are meaningful because uveal melanoma is notoriously resistant to conventional chemotherapy. In January 2026, UT Southwestern became the first center in Texas to perform the Hepzato Kit procedure, underscoring that access is still expanding across the country. The treatment is not available everywhere and requires a specialized interventional radiology team, which can be a barrier for patients in rural areas or those whose cognitive or physical condition makes travel difficult. A notable development came in March 2026, when the Dutch CHOPIN Phase II trial — published in The Lancet Oncology — showed that combining percutaneous hepatic perfusion with nivolumab and ipilimumab (two checkpoint inhibitors) significantly improved progression-free survival compared to PHP alone. This combination approach could reshape how liver-directed therapy is used, though it also adds immunotherapy side effects on top of the procedural risks of PHP. Patients and caregivers should understand that Hepzato Kit involves a complex inpatient procedure, not simply an infusion, and recovery can be demanding — a critical consideration for elderly patients or those with co-existing conditions like dementia.
Darovasertib — The Pipeline Drug That Could Change Treatment for HLA-Negative Patients
For the roughly half of metastatic uveal melanoma patients who do not carry HLA-A*02:01 and therefore cannot receive Kimmtrak, the pipeline drug darovasertib offers perhaps the most tangible hope. Developed by IDEAYA Biosciences, darovasertib is a first-in-class selective protein kinase C (PKC) inhibitor that targets a biological vulnerability shared by approximately 90% of all uveal melanomas: mutations in the GNAQ or GNA11 genes. These driver mutations are nearly universal in uveal melanoma but rare in other cancers, making them an attractive therapeutic target. Phase 2 results reported in October 2025 showed that darovasertib combined with crizotinib achieved a median overall survival of 21.1 months — comparable to Kimmtrak’s results — with a progression-free survival of 7.0 months, a 34% objective response rate, and a 90% disease control rate.
By December 2025, IDEAYA had completed enrollment of 435 patients in the pivotal Phase 2/3 OptimUM-02 trial, with median progression-free survival data expected in the first quarter of 2026 to support a potential accelerated FDA approval. The comparison between Kimmtrak and darovasertib highlights an important tradeoff. Kimmtrak has proven survival data and FDA approval but is limited to HLA-A*02:01-positive patients and causes significant side effects — rash in 83% of patients, fever in 76%, itching in 70%, and hypotension in 38%. Darovasertib, if approved, would serve a different and complementary patient population (HLA-negative patients in the current trial design) and works through an entirely different mechanism. Rather than competing directly, these drugs may end up being used sequentially or in combination as the treatment landscape matures.
Side Effects, Cost, and the Practical Realities of Treatment
The side effect profile of Kimmtrak deserves careful attention, especially for older adults who may already be managing multiple medical conditions. The most common adverse effects reported in clinical trials include rash (83% of patients), pyrexia or fever (76%), pruritus or itching (70%), and hypotension or low blood pressure (38%). The first three doses carry the highest risk of severe reactions, and patients must be monitored in a clinical setting for at least 16 hours after the first infusion and for shorter periods after subsequent doses. For patients with dementia, these side effects are not merely uncomfortable — fever and hypotension can worsen confusion, agitation, and delirium, creating a cascade of problems that extend well beyond the cancer itself. Then there is cost. Kimmtrak is priced at approximately $18,760 per vial, administered weekly, with an estimated annual treatment cost of $400,000 to $500,000.
While insurance and manufacturer assistance programs may offset some of this burden, the financial reality is daunting. Hepzato Kit, as a procedural treatment, carries its own significant costs related to the specialized equipment, interventional radiology team, and inpatient hospital stay required for each session. Families should have frank conversations with the oncology team about expected out-of-pocket costs before beginning treatment, particularly when the patient’s prognosis and quality-of-life goals must be weighed against the financial strain. One warning that does not appear often enough in patient literature: beginning treatment with Kimmtrak requires HLA typing, which is a simple blood test but must be ordered proactively. Not all community oncologists are familiar with uveal melanoma or aware that this test is a prerequisite. If you or a loved one has been diagnosed with metastatic uveal melanoma, requesting a referral to a melanoma-specialized academic center can make a significant difference in both the speed and quality of care.
The Neoadjuvant Promise — Treating the Eye Tumor Before It Spreads
One of the more encouraging findings to emerge recently involves using darovasertib not for metastatic disease, but for the primary tumor still in the eye. In neoadjuvant studies — meaning treatment given before definitive surgery or radiation — darovasertib shrank primary uveal melanoma tumors by 20% or more in 76% of patients. Even more striking, 57% of patients achieved eye preservation, and that rate climbed to 95% among those whose tumors shrank by at least 20%.
This matters because the traditional treatment for a large uveal melanoma is enucleation — surgical removal of the entire eye. If a drug can shrink the tumor enough to allow eye-sparing radiation therapy instead, the quality-of-life implications are profound. For older adults, preserving vision in both eyes affects everything from fall risk to independence to the ability to participate in cognitive stimulation activities that depend on visual engagement. Should darovasertib receive FDA approval for metastatic disease, its potential use in earlier-stage uveal melanoma could eventually change the standard of care for the primary tumor as well.
Where Uveal Melanoma Treatment Is Headed in 2026 and Beyond
The uveal melanoma treatment landscape is evolving faster now than at any point in the disease’s history. Immunocore is not resting on Kimmtrak’s success — the company has two Phase 3 trials underway (TEBE-AM and ATOM) exploring new melanoma indications, and is running the PRISM-MEL-301 trial evaluating brenetafusp, a next-generation bispecific T-cell engager, as a first-line treatment for cutaneous melanoma. If brenetafusp succeeds, it would validate the entire bispecific TCE platform beyond the narrow uveal melanoma indication.
Meanwhile, the convergence of liver-directed therapy (Hepzato Kit), systemic immunotherapy (Kimmtrak), and targeted therapy (darovasertib) suggests that future treatment may involve combinations or sequences tailored to individual patients based on their HLA status, liver tumor burden, and overall health. For families navigating these decisions alongside dementia care, the growing number of options is both a blessing and a source of complexity. The most important step a caregiver can take is to ensure their loved one is seen at a center with specific uveal melanoma expertise, where the full range of emerging treatments can be evaluated in context rather than offered piecemeal.
Conclusion
The rare eye cancer known as uveal melanoma has gone from a therapeutic wasteland to a space with two FDA-approved treatments and a third likely on the horizon. Kimmtrak broke through as the first drug ever to extend survival in metastatic uveal melanoma, Hepzato Kit offered a liver-directed alternative for patients with hepatic-dominant disease, and darovasertib may soon fill the critical gap for HLA-negative patients who cannot access Kimmtrak.
Each approach has distinct benefits and limitations — from Kimmtrak’s immune-mediated side effects and genetic eligibility requirements, to Hepzato Kit’s procedural complexity, to darovasertib’s still-pending regulatory status. For caregivers supporting someone with both cognitive decline and a cancer diagnosis, the practical takeaways are clear: pursue HLA typing early, seek out academic medical centers with uveal melanoma programs, have honest conversations about treatment goals and financial realities, and maintain advance directives that reflect the patient’s wishes. The science has advanced remarkably in just a few years, and the pipeline suggests further progress is coming — but navigating these options requires informed advocacy, especially when the patient may not be able to advocate for themselves.
Frequently Asked Questions
What is uveal melanoma, and how common is it?
Uveal melanoma is the most common primary cancer of the eye in adults, but it is still rare, with approximately 2,500 new cases diagnosed annually in the United States. It develops in the pigmented cells of the uveal tract — typically in the choroid at the back of the eye — and about 50% of patients eventually develop metastatic disease, most often in the liver.
Who is eligible for Kimmtrak treatment?
Kimmtrak is approved for adults with unresectable or metastatic uveal melanoma who test positive for the HLA-A*02:01 immune marker. This marker is found in roughly 40-50% of people of European descent and at lower rates in other populations. A blood test for HLA typing is required before treatment can begin.
How much does Kimmtrak cost?
Each weekly dose of Kimmtrak costs approximately $18,760 per vial, which translates to an estimated annual treatment cost of $400,000 to $500,000. Insurance coverage, manufacturer assistance programs, and patient support services may reduce out-of-pocket costs, but the financial burden remains significant.
What is the Hepzato Kit, and how is it different from Kimmtrak?
The Hepzato Kit, approved by the FDA on August 14, 2023, delivers high-dose melphalan chemotherapy directly to the liver through a procedure called percutaneous hepatic perfusion. Unlike Kimmtrak, which is a systemic immunotherapy infusion, Hepzato Kit is a liver-directed procedure that isolates the organ’s blood supply to concentrate chemotherapy where metastases most commonly occur, while filtering the drug before it recirculates through the body.
What is darovasertib, and when might it be approved?
Darovasertib is an investigational PKC inhibitor developed by IDEAYA Biosciences that targets mutations found in approximately 90% of uveal melanomas. It completed enrollment of 435 patients in its pivotal Phase 2/3 trial in December 2025, with key data expected in the first quarter of 2026 to support potential accelerated FDA approval. It is particularly important for HLA-A*02:01-negative patients who cannot receive Kimmtrak.
Should a patient with dementia be treated for metastatic uveal melanoma?
This is a deeply individual decision that depends on the stage of dementia, the patient’s previously expressed wishes, the extent of metastatic disease, and the specific treatment being considered. Kimmtrak’s side effects — particularly fever and low blood pressure — can worsen confusion and agitation in patients with cognitive impairment. Families should work closely with both the oncology team and the patient’s neurologist or geriatrician to weigh the potential benefits against the burdens of treatment.
