HLA-A2-Negative Uveal Melanoma: Darovasertib Plus Crizotinib Reduced Progression Risk by 58%
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The OptimUM-02 Study: A New Strategy for HLA-A2-Negative Metastatic Uveal Melanoma
Why is the HLA-A2-negative group a distinct problem in uveal melanoma?
Uveal melanoma is biologically different from cutaneous melanoma. BRAF mutations, common in cutaneous melanoma, are not typical of uveal melanoma. Instead, most patients have GNAQ or GNA11 mutations, which activate the PKC pathway. Liver metastasis is very common in metastatic uveal melanoma, and responses to conventional immunotherapy are generally limited.
Tebentafusp has become an important treatment standard for HLA-A*02:01-positive patients. However, HLA-A*02:01-negative patients cannot benefit from this treatment. Because most patients with metastatic uveal melanoma are estimated to be HLA-A*02:01 negative, the lack of an approved, effective systemic treatment for this group is a major clinical unmet need.
HLA is a family of molecules that enables the immune system to present fragments of cellular proteins to T cells. Some T-cell-redirecting treatments, such as tebentafusp, work only in patients with a particular HLA type. HLA-A*02:01-negative patients are not biologically eligible for tebentafusp.
Why are darovasertib and crizotinib used together?
Darovasertib is an oral PKC inhibitor. Because GNAQ/GNA11 mutations activate the PKC signaling pathway in uveal melanoma, PKC becomes a rational target in this disease. Crizotinib is an oral tyrosine kinase inhibitor targeting kinases such as MET and ALK/ROS1. In uveal melanoma, the HGF/MET axis may be associated with tumor growth and mechanisms of resistance.
The rationale for the combination is to suppress not a single signaling pathway, but two growth/survival pathways that can reinforce one another in the uveal melanoma cell: the GNAQ/GNA11-PKC axis and the HGF/MET axis.
Protein kinase C is a family of proteins involved in cell growth, survival, and signal transduction. In uveal melanoma, the PKC pathway can become persistently active through GNAQ/GNA11 mutations; PKC inhibition is therefore biologically meaningful in this disease.
Study design: How was OptimUM-02 conducted?
OptimUM-02 is a multi-arm, multistage, open-label phase 2/3 study comparing darovasertib + crizotinib with investigator-selected treatment in HLA-A*02:01-negative metastatic uveal melanoma. It was conducted in a first-line metastatic disease population.
In the phase 2b/3 efficacy analysis, darovasertib 300 mg + crizotinib 200 mg twice daily was administered to 210 patients; these patients were compared with 103 patients receiving investigator-selected treatment. The control arm theoretically offered pembrolizumab, ipilimumab + nivolumab, or dacarbazine; however, in the analyzed control population, 76,7% received ipilimumab + nivolumab, 23,3% received pembrolizumab ; no patient received dacarbazine.
| Item | Darovasertib + crizotinib | Investigator-selected treatment | Clinical significance |
|---|---|---|---|
| Efficacy population | 210 patients | 103 patients | Phase 2b/3 ITT efficacy analysis. |
| Treatment | Darovasertib 300 mg + crizotinib 200 mg, twice daily | Pembrolizumab or ipilimumab + nivolumab; dacarbazine was an option in the protocol | PKC + MET targeting was compared with off-label immunotherapy options used in clinical practice. |
| Actual control distribution | Not applicable | 76,7% ipilimumab + nivolumab; 23,3% pembrolizumab; 0% dacarbazine | The control arm largely represents real-world practice based on immunotherapy. |
| Primary analysis | PFS by BICR | An endpoint intended to form the basis of the FDA submission. | |
| Secondary endpoints | ORR, DOR, 12-week DCR, investigator-assessed PFS, safety, and OS | OS data are not yet mature. | |
Patient characteristics: A population dominated by liver metastases
Mean age in the combination arm was 61,1, compared with 61,5 in the control arm. Performance status was generally good; in the combination arm, 77,1% had ECOG 0, compared with 84,5% with ECOG 0 in the control arm.
The distribution of metastatic disease was liver predominant, as expected in uveal melanoma. In the combination arm, liver-only metastases accounted for %60,5, and liver + extrahepatic metastases for %34,3; in the control arm, liver-only metastases accounted for %63,1, and liver + extrahepatic metastases for %30,1 .
Main result: PFS more than doubled
Median follow-up was 7,4 months . By BICR, median PFS was reported as 6,9 monthsin the darovasertib + crizotinib arm, compared with 3,1 months in the investigator-selected treatment arm. HR was 0,42, with p<0,0001. This represents an approximately 58% relative reduction in the risk of progression or death.
Investigator assessments showed results in the same direction: median PFS was 6,7 months and 2,7 months ; HR was 0,36, with p<0,0001. Subgroup analyses reported consistent PFS benefit across groups defined by age, sex, ECOG performance status, largest target lesion size, and metastatic pattern.
Response rate: Marked superiority over the control arm
By BICR, the objective response rate was %37,1in the combination arm, compared with %5,8 in the control arm. The combination arm reported 5 complete responses ; there were no complete responses in the control arm. Median duration of response in the combination arm was 6,8 months .
| Outcome | Darovasertib + crizotinib | Investigator’s choice | Clinical interpretation |
|---|---|---|---|
| BICR median PFS | 6,9 months | 3,1 months | HR 0,42; 58% reduction in the risk of progression or death. |
| Investigator-assessed median PFS | 6,7 months | 2,7 months | HR 0,36; result consistent with BICR. |
| BICR ORR | %37,1 | %5,8 | Response rate approximately 6 times higher. |
| Complete response | 2,4%; 5 patients | %0 | No complete responses in the control arm. |
| 12-week DCR | %73,3 | %31,1 | Markedly higher early disease control. |
| Median DOR | 6,8 months | Not evaluable | DOR has limited interpretability because there were very few responses in the control arm. |
| OS | Not yet mature; an early favorable trend was reported | Final OS data should be awaited. | |
Safety: Gastrointestinal and edema-related adverse effects predominate
The combination arm had a high rate of treatment-related adverse effects of any grade; however, rates of treatment-related serious adverse events and treatment discontinuation were lower than in the control arm. The rate of treatment-related serious adverse events in the darovasertib + crizotinib arm was %9,2, compared with %25,0 in the control arm. Events leading to complete treatment discontinuation were reported as %0,8 and %5,0 , respectively.
In the combination arm, the most common treatment-related adverse effects of any grade were diarrhea %84,9, nausea %74,9, peripheral edema %66,9, vomiting %49,8, acneiform dermatitis %41,8, fatigue %39,3 , and hypotension %33,1 .
The rate of grade 3/4 treatment-related adverse effects was %40,6in the combination arm, compared with %37,0 in the control arm. In the combination arm, the most common grade 3/4 adverse effects were diarrhea %10,0, syncope %7,1, hypotension %3,8, nausea %2,9, peripheral edema %2,9 , and anemia %2,5 .
Practical safety message
Darovasertib + crizotinib is an oral targeted combination, but it should not be viewed as “easy tablet therapy.” Close monitoring is required for diarrhea, nausea and vomiting, edema, hypotension, syncope, and skin toxicity. Especially during the first weeks, fluid balance, blood pressure, electrolytes, antiemetic/antidiarrheal support, and dose management are part of treatment success.
Regulatory status: Is there FDA approval?
Darovasertib is not currently an FDA-approved drug. The FDA has granted darovasertib orphan drug designation for uveal melanoma; the FDA orphan drug record states “not FDA approved for orphan indication” for darovasertib. The darovasertib + crizotinib combination has received Fast Track designation in metastatic uveal melanoma. Based on the OptimUM-02 data, the company aims to submit an NDA in the United States in the second half of 2026. Therefore, this treatment is not a standard, approved routine option today, but a strong investigational candidate awaiting a regulatory submission.
The important distinction for patients is this: the data are promising , but there is no FDA approval yet. Until the approval process is completed, access to darovasertib + crizotinib may be limited to clinical trials, expanded access, or country-specific special programs.
How does it relate to tebentafusp?
Tebentafusp is an FDA-approved treatment for HLA-A*02:01-positive metastatic uveal melanoma and has demonstrated an overall survival advantage. However, this treatment is for HLA-A*02:01-positive patients. The importance of darovasertib + crizotinib, conversely, lies in its being studied in HLA-A*02:01-negative patients.
| Item | Tebentafusp | Darovasertib + crizotinib | Clinical interpretation |
|---|---|---|---|
| HLA status | HLA-A*02:01 positive | HLA-A*02:01 negative | The two treatments address biologically different patient groups. |
| FDA approval | Approved | Not yet approved; an NDA is planned | The darovasertib combination is in the regulatory process. |
| Mechanism | gp100-HLA-directed T-cell engager | Oral combination targeting PKC + MET | One is an immune-redirecting strategy; the other suppresses targeted signaling. |
| Main clinical gap | HLA-A2-positive patients | Lack of an approved option for HLA-A2-negative patients | OptimUM-02 addresses this gap. |
Critical reading: How should these data be interpreted in a balanced way?
Strong points that require careful interpretation
- PFS and ORR are very strong: PFS HR 0,42 and BICR ORR 37,1% provide important randomized data for HLA-A2-negative metastatic uveal melanoma.
- OS is not yet mature: An early favorable trend was reported; however, interpretation as a survival standard should remain cautious until final OS data are available.
- The control arm reflects real-world practice but is heterogeneous: Most patients received ipilimumab + nivolumab, and some pembrolizumab; dacarbazine was not used.
- Toxicity is substantial despite oral treatment: Diarrhea, nausea, edema, hypotension, and syncope require close monitoring.
- No FDA approval: Darovasertib is investigational; orphan designation and Fast Track designation do not constitute approval.
- There are real-world questions in liver-predominant disease: High tumor burden, liver function, elevated LDH, and integration with local liver treatments will be decisive in clinical practice.
- The findings should not be generalized to HLA-A2-positive patients: This study was conducted in an HLA-A*02:01-negative population; tebentafusp is a separate approved standard for HLA-A2-positive patients.
Message for clinical practice
OptimUM-02 is a strong study showing that the HLA-A2-negative group in metastatic uveal melanoma may no longer have to be left with immunotherapy alone because “there is no standard option.” Darovasertib + crizotinib has become one of the most important candidates demonstrating the clinical translation of targeted biology in this disease in a randomized study.
However, this treatment is not routinely approved today. Its entry into clinical practice will be determined by FDA assessment, country-specific licensing, and access processes. The most important message of this article for patients is that a new, promising targeted combination has provided strong phase 2/3 data in HLA-A2-negative metastatic uveal melanoma, but the approval process has not yet been completed.
How should this be explained to the patient?
“Treatment options are limited when uveal melanoma metastasizes. The approved treatment called tebentafusp can be used only in HLA-A2-positive patients. This study investigated the combined use of two oral targeted drugs, darovasertib and crizotinib, in HLA-A2-negative patients. The combination delayed disease progression and increased the rate of tumor shrinkage. However, this treatment is not yet FDA approved; the approval application process is awaited.”
Drozdogan Academic Commentary
OptimUM-02 provides some of the strongest randomized data for HLA-A2-negative patients, who have long represented one of the largest unmet needs in metastatic uveal melanoma.
The darovasertib + crizotinib combination extended PFS to 6,9 months versus 3,1 months, increased ORR to 37,1%, and yielded 5 complete responses. These findings show that simultaneously targeting the PKC + MET axis may translate into genuine clinical benefit in this disease.
However, OS data are not yet mature, and the drug is not FDA approved. The most appropriate interpretation, therefore, is that darovasertib + crizotinib is a potential new standard candidate in HLA-A2-negative metastatic uveal melanoma, but its definitive clinical role will be determined by the regulatory decision, final OS data, real-world tolerability, and access conditions.
Conclusion
Presented at ASCO 2026, the OptimUM-02 study showed that first-line darovasertib + crizotinib significantly improved PFS and ORR compared with investigator-selected treatment in HLA-A*02:01-negative metastatic uveal melanoma. By BICR, median PFS was 6,9 months versus 3,1 months, HR 0,42; BICR ORR was 37,1% versus 5,8%; 12-week DCR was 73,3% versus 31,1% .
Although the safety profile appears manageable, adverse effects such as diarrhea, nausea, edema, hypotension, and syncope require regular monitoring. The lower rates of treatment-related serious adverse events and treatment discontinuation compared with the control arm are a favorable finding.
Darovasertib + crizotinib is not yet FDA approved; however, based on these data, an NDA submission in the United States is planned for the second half of 2026. If approved, it could become one of the first genuine targeted systemic standards in HLA-A2-negative metastatic uveal melanoma.
- OncLive. Darovasertib Plus Crizotinib Delivers PFS Gains in HLA-A2–Negative Metastatic Uveal Melanoma. 2026.
- ASCO 2026 LBA9503. Darovasertib plus crizotinib vs investigator’s choice as first-line treatment for patients with HLA-A2 negative metastatic uveal melanoma.
- IDEAYA Biosciences and Servier. Positive topline results from OptimUM-02. 13 April 2026.
- IDEAYA Biosciences and Servier. Complete data from OptimUM-02 at ASCO 2026. 2026.
- ClinicalTrials.gov. OptimUM-02 / NCT05987332.
- FDA Orphan Drug Designations and Approvals. Darovasertib for treatment of uveal melanoma.
- FDA. Tebentafusp-tebn approval for HLA-A*02:01-positive unresectable or metastatic uveal melanoma. 2022.
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