NEW YORK — Patients with metastatic melanoma treated with high-dose interleukin-2 demonstrated improved OS compared with historical reference standards, according to study results presented at the HemOnc Today Melanoma and Cutaneous Malignancies meeting.
Prior studies designed to assess the efficacy of high-dose interleukin-2 [IL-2 (Proleukin, Prometheus)] in patients with metastatic melanoma showed an overall response rate of 16% and a median OS of 11.4 months. However, the studies that supported the agent’s regulatory approval were conducted more than 15 years ago, prior to the development of targeted therapies and checkpoint inhibition, according to study background.
Sandra Aung, associate director for oncology at Prometheus Labs in San Diego, and colleagues analyzed data from the PROCLAIM 2007-2012 National Registry. The registry — comprised of observational data from more than 30 sites — includes retrospective data from a cohort treated from 2007 to 2012, as well as an ongoing prospective cohort.
Their analysis focused on 170 patients from the retrospective cohort whose survival status was determined as of November 2013. Ninety-eight were deceased and 72 were alive.
All patients received at least one dose of high-dose IL-2. Median follow-up was 30.5 months.
Results showed median OS was 21 months, which compared favorably to the median OS range for monotherapy with other FDA-approved agents, Aung and colleagues wrote.
Patients with stable disease demonstrated considerably longer median OS than those with progressive disease (36.6 months vs. 15.4 months). Median OS had not been reached for patients who achieved partial response or complete response, Aung and colleagues wrote.
The researchers observed no significant difference in OS between patients who received high-dose IL-2 as first-line treatment (n = 138) or second-line treatment (n = 32). No deaths attributed to IL-2–related toxicities were reported.
“Responses to high-dose IL-2 traditionally [are] defined as complete response or partial response and — according to this data — should also include stable disease, which can be very durable,” Aung and colleagues wrote. “The observation that first- and second-line high-dose IL-2 [conferred] similar OS raises intriguing hypotheses about the sequencing of immunotherapy and targeted therapy in metastatic melanoma and the utility of IL-2 as a salvage option, all of which are currently under examination in the prospective database.” – by Cameron Kelsall
Aung S, et al. Improved median overall survival (OS) in patients with metastatic melanoma (mM) treated with high dose (HD) IL-2: analysis of the PROCLAIM 2007-2012 national registry. Presented at: HemOnc Today Melanoma and Cutaneous Malignancies; April 10-11, 2015; New York.
Disclosure: Aung reports an employment relationship with Prometheus. See the full study for all other researchers’ relevant financial disclosures.