1134P - Long-term survival of patients with advanced melanoma treated second line with ipilimumab

Date 01 October 2012
Event ESMO Congress 2012
Session Poster presentation III
Topics Cancer Immunology and Immunotherapy
Melanoma and other Skin Tumours
Presenter Dawn Lee
Authors D. Lee1, L. Pericleous2, M. Lebmeier2, A. Batty3, B. Winn3, T. Nikoglou2
  • 1BresMed, S1 2DW - Sheffield/UK
  • 2Health Economics And Outcomes, Bristol Myers Squibb, UB8 1DH - Uxbridge/UK
  • 3Health Economics, BresMed, S1 2DW - Sheffield/UK

Abstract

Objective

To estimate the long-term survival of patients with advanced melanoma treated second-line with ipilimumab 3 mg/kg compared to no active treatment (best supportive care [BSC]).

Methods

At the end of the Phase III trial (MDX010-20) 17% of patients receiving ipilimumab were alive compared to 4% of those receiving GP100: median follow up 28 months, maximum 55 months. Trial data were used to model survival beyond the trial period. GP100 has been shown to have no impact on survival (within MDX010-20 and a mixed treatment comparison). GP100 arm data were used to model survival of patients receiving BSC. Two groups were seen: Patients who experience therapy benefit and enter a stable period leading to a gradual plateau of the KM curve; Patients whose immune systems do not respond quickly and die causing an initial steep drop in the KM curve Standard modelling techniques did not fit the available data well and underestimated the durable response of immunotherapy. Around 18 months the mortality hazard was shown to change in the ipilimumab arm meaning that different methods were required to predict survival before and after this time. We estimated long-term survival as follows: · ≤18 Months Kaplan-Meier data was used, mimicking survival within the trial · >18 Months - 5 years (representing the maximum data available from MDX-010-20) a standard parametric curve was fitted to the data · >5 years 15 year registry data from Balch et al (2001) for Stage IV melanoma and background mortality were used to estimate long-term survival.

Results

Using the three-part approach reduced the mean absolute error (MAE) associated with the curve fits. Those selected having an MAE of 0.003 (0.004 for long-term survivors) on the ipilimumab arm, and 0.008 (0.012 for long-term survivors) on the BSC arm. This compares to a MAE at least 7 x higher (0.06) for standard parametric curves. For BSC patients, the model predicts mean survival of 1.2 years whereas those taking ipilimumab are expected to survive for a mean of 3.7 years. This is due to more patients remaining alive beyond 5-years, after which death from melanoma is less likely.

Conclusion

Treatment with ipilimumab provides a substantial increase in survival over BSC in the second-line treatment of advanced melanoma.

Disclosure

D. Lee: Funding for the analysis conducted was provided to BresMed by BMS. I have not received any personal funding and do not have any personal interest in BMS or any competitor products.

L. Pericleous: I have worked for BMS. Other than this I have not received any personal funding and do not have any personal interest in BMS or any competitor products.

M. Lebmeier: I work for BMS. Other than this I have not received any personal funding and do not have any personal interest in BMS or any competitor products.

B. Winn: Funding for the analysis conducted was provided to BresMed by BMS. I have not received any personal funding and do not have any personal interest in BMS or any competitor products.

A. Batty: Funding for the analysis conducted was provided to BresMed by BMS. I have not received any personal funding and do not have any personal interest in BMS or any competitor products.

T. Nikoglou: I work for BMS. Other than this I have not received any personal funding and do not have any personal interest in BMS or any competitor products.