Is the Juice Worth the Squeeze? Overall Survival Gain per Unit Treatment Time as a Metric of Clinical Benefit of Systemic Treatment

Abstract

Aims

Novel systemic therapeutic options such as enzyme inhibitors and monoclonal antibodies have transformed the practice of medical oncology in the recent past. However, survival gains remain modest in most cases. Quantifying the magnitude of benefit against financial and nonfinancial toxicity of treatment is pivotal in deciding treatment. We describe a novel metric which can be used to assess effectiveness of novel therapeutics for incurable cancers along with other established tools.

Materials and methods

Sixty indications of 30 novel therapeutic agents were selected for analysis. The median overall survival gain was divided by the median duration of treatment to obtain the overall survival gain per treatment time, which was the primary end-point of the study. This parameter was compared with the European Society of Medical Oncology Magnitude of clinical benefit scale (ESMO-MCBS) score. Spearman’s rank correlation coefficient was used to test the association between the novel metric and the ESMO-MCBS scores.

Results

The median overall survival per unit treatment time ranged from 0.68 (range: 0.2–0.51). Only 18/60 indications had a ratio greater than 1, while 13/60 indications had a ratio less than 0.5. The median treatment duration was not mentioned in 12 indications and median progression-free survival was substituted for the analysis. The ESMO-MCBS score was available for 49 of the indications. The Spearman’s rank correlation coefficient was 0.44575 and showed a statistically significant association between survival gain per unit treatment time and the ESMO-MCBS score (P = 0.00133).

Conclusion

Along with other metrics, the ratio of survival gain over treatment duration is a useful parameter to assess effectiveness of novel therapeutics in the palliative setting.