Study shows improved OS with Proleukin in metastatic Renal Cell Carcinoma - Prometheus Labs

Analysis of data from the PROCLAIM national patient registry retrospective cohort shows improved overall survival in metastatic Renal Cell Carcinoma patients treated with high-dose Proleukin (aldesleukin), from Prometheus Laboratories, in the tyrosine kinase inhibitor (TKI) era versus that previously published by the NCI in patients treated prior to 2005. The survival benefit was observed to extend to patients with stable or progressive disease after High-Dose Interleukin-2 (HD IL-2) when compared to results in patients receiving only TKI. It also demonstrated a trend favoring patients receiving first-line versus second-line HD IL-2 immunotherapy, suggesting that patient selection and drug sequencing may yield better outcomes.

Ninety seven US patients with mRCC who received at least one dose of HD IL-2 were followed for a median duration of 37.1 months. The overall response rate (ORR) to IL-2 therapy was 22%, with an additional 24% of patients with stable disease (SD). The median OS rate from the time of HD IL-2 administration was 51 months. This compares favorably with the median survival of 19 months observed in the pre-2006 NCI series of HD IL-2 alone. The researchers reported a significant clinical benefit in patients with CR, PR, and stable disease (SD), none of whom have reached median OS; by comparison, median OS was 40.2 months in patients with progressive disease (PD).

In the past, it was believed that benefit from HD IL-2 was limited to the small proportion who achieved complete and partial responses. In addition, median OS was 61.8 months for the 82 patients treated with first-line HD IL-2 therapy, compared to 48 months for the 15 patients who received IL-2 after prior TKI therapy. Data was presented at the 50th annual meeting of the American Society of Clinical Oncology (ASCO).