Uveal melanomas are a rare type of melanoma with only 5-7 cases per 1 million persons diagnosed each year. Patients with metastatic melanoma of uveal origin, tend to have lower response rates on traditional therapies, as well as are usually excluded from clinical trials.
Researchers have reported the experience with 7 patients with metastatic uveal melanoma who received Pembrolizumab ( keytruda ) as part Merck’s expanded access program.
Patients were considered eligible for treatment on this protocol, if they were gretaer than or equal to 12 years old, diagnosed with unresectable metastatic melanoma, had progressed on prior Ipilimumab therapy, and if BRAF mutant had progressed on BRAF inhibition therapy.
Patients had to have good performance status ( ECOG of 0 or 1 ) and adequate organ and marrow function.
Patients could have CNS disease, but needed to be clinically stable, prior to enrollment and could not be receiving other concurrent therapy for their cancer.
Patients were treated with 2 mg/kg of Pembrolizumab IV over q3 weeks until disease progression, unacceptable toxicity or for up to 2 years.
A total of 7 patients with metastatic uveal melanoma onto study MK-3475-030 were enrolled. Median age at enrollment was 64, with 5 patients being female.
As of the data cutoff date of 1/27/2014 median progression free survival was 12.2 weeks ( range 3.14-41 ) with 2 patients still currently receiving therapy without progression.
There was 1 CR ( complete response ), 1 PR ( partial response ) and 1 patient with SD ( stable disease ).
Three patients had disease progression and 1 patient was excluded as she discontinued therapy after 1 dose due to grade 4 endocrine toxicity.
Other toxicities were as expected and were usually grade 1 or 2 in nature.
In conclusion, while this cohort of patients was small, this is the first such report of outcomes in uveal melanoma patients being treated with anti-PD1 therapy.
Toxicities were acceptable and expected.
Patients were all pretreated, most with 2+ regimens.
Treatment with Pembrolizumab appears to be a viable option for patients with metastatic uveal melanoma. ( Xagena )
Kottschade LA et al, J Clin Oncol 33, 2015 (suppl; abstr 9010)