Figure 2. PDX data show that because different tumors respond to different drugs, independent drug action is sufficient for a combination therapy to improve response distribution in a population.
A. Correlations in drug response (Spearman’s Rho applied to PFS) were calculated from PDX trials where the same tumors receive many different treatments (Gao et al., 2015) (Methods). B. Progression free survival measured by Gao et al. in 41 patient-derived gastric cancer xenografts, when treated with Alpelisib (PI3K inhibitor) or with LLM871 (FGFR2/4 antibody-drug conjugate). C. Probability of progression free survival in gastric cancer xenografts when treated with Alpelisib, or LLM871, or a hypothetical combination of the two drugs assuming independent action, where each tumor’s response is the best one of its observed responses to the two monotherapies.