Just a quick update before diving in: I’ll be starting at AdventHealth on December 1st, 2025, and I’m really looking forward to this next chapter. If you’ve noticed a lull in posts lately, it’s because I’ve been buried in board review—studying for my hematology recertification—while also ramping up with my wife on our first 4EverYoung franchise location, and managing some real estate projects that demanded attention. I’m hoping to get back to sharing more medically focused content in the weeks ahead.
At the 2025 ESMO Congress in Berlin, Dr. Marcus Butler presented compelling phase 2 data from the OptimUM-09 trial, evaluating neoadjuvant darovasertib —a first-in-class PKC inhibitor—for patients with primary uveal melanoma. These results may herald a paradigm shift toward what we might soon call “ocular-sparing oncology.”
Background: Why This Matters
Uveal melanoma (UM) is a rare malignancy arising from melanocytes within the uveal tract of the eye. While systemic metastatic risk has long been the focus of research, local control remains a major challenge. For many patients, large or posteriorly located tumors leave little choice but enucleation—complete removal of the affected eye. Even with plaque radiotherapy, significant visual loss is common.
At the molecular level, uveal melanoma is characterized by mutations in GNAQ and GNA11, which activate PKC (protein kinase C) signaling, leading downstream to RAS/RAF/MEK/ERK pathway activation. Until now, therapeutic attempts have mostly targeted downstream effectors like MEK. Darovasertib takes a different approach, targeting PKC directly—upstream in the cascade.
Study Design: The OptimUM-09 Trial
This phase 2, single-arm study explored neoadjuvant darovasertib in two cohorts:
- Cohort 1: Patients who would otherwise require enucleation.
- Cohort 2: Patients eligible for plaque radiotherapy.
Participants received oral darovasertib 300 mg BID, in 28-day cycles for up to 12 cycles, with the possibility of additional adjuvant therapy for six cycles following surgery or radiotherapy.
The study’s primary endpoints included eye preservation (Cohort 1) and radiation dose reduction (Cohort 2)—both aiming to maximize vision preservation and quality of life.
Results: Tumor Shrinkage and Vision Preservation
In total, 95 patients were enrolled (56 in Cohort 1, 39 in Cohort 2). The median tumor thickness was 10 mm in Cohort 1 and 8 mm in Cohort 2, with most patients presenting with T3–T4 disease.
Tumor response was robust:
- Cohort 1: Tumor reduction in 83.9% of patients;
57% achieved eye preservation, avoiding enucleation. - Cohort 2: Tumor reduction in 81% of patients;
~60% had ≥20% reduction in tumor size.
Across both cohorts, vision improvement or stabilization was observed in approximately 50–60% of patients during therapy—a clinically meaningful result for a disease where functional vision loss is often inevitable.
Importantly, the estimated three-year risk reduction in severe vision loss was approximately 64%, underscoring not only radiographic but also functional benefit.
Safety and Tolerability
Darovasertib was well tolerated overall. Most adverse events were low grade, including diarrhea, nausea, fatigue, and mild rash. Grade ≥3 toxicities were infrequent (≈5%), and only 6% of patients discontinued treatment due to side effects. This tolerability profile supports the feasibility of neoadjuvant and adjuvant use in a sensitive organ system.
A Step Toward Ocular-Sparing Oncology
The concept of organ preservation is familiar in surgical oncology—whether through sphincter-sparing rectal surgery or limb-sparing procedures in sarcoma. For uveal melanoma, the notion of ocular-sparing therapy has long seemed aspirational. The OptWM09 data suggest that this aspiration may soon become a reality.
With meaningful tumor shrinkage, preserved vision, and manageable toxicity, darovasertib could represent a new frontier in the treatment of primary uveal melanoma. The ongoing OptWM10 phase 3 registrational trial will test this hypothesis in a randomized setting, comparing standard approaches (enucleation or plaque radiotherapy) with darovasertib-based regimens.
If confirmed, this could redefine standard care—transforming treatment goals from “remove or radiate” to “preserve and protect.”
In Summary
- Drug: Darovasertib – first-in-class PKC inhibitor
- Disease: Primary uveal melanoma
- Key outcomes:
- Tumor reduction in ~80%
- Eye preservation in 57% (Cohort 1)
- Vision preservation in ~60% overall
- Well-tolerated safety profile
- Next step: OptWM10 phase 3 registrational trial
ESMO 2025 takeaway: Uveal melanoma may soon enter an era where precision medicine meets organ preservation—a combination as visionary as the organ it aims to protect.
About the author
Dr. Sajeve Thomas is a distinguished medical professional and a compassionate guide in the field of oncology. With over a decade of dedicated experience as a board-certified medical oncologist/internal medicine specialist, Dr. Thomas has become a trusted expert in the treatment of melanoma, sarcoma, and gastrointestinal conditions. He brings a wealth of expertise to the complex and challenging world of oncology.
Disclosures:
Dr. Thomas serves as a speaker for Bristol Myers Squibb (BMS), Merck, Ipsen, Natera, Immunocore, Pfizer, and SpringWorks. He also receives industry grants in support of numerous clinical trials.