Figure 4: Serial analysis of ctDNA mutation AF changes binned by best clinical response.

(a) ESR1 and (b) PIK3CA ctDNA mutation AF changes while on part 1 (green) or part 2 (blue) pictilisib+fulvestrant or placebo+fulvestrant (grey) treatment arms. Patients are binned according to their best clinical response: CR/PR defined by RECIST criteria, and SD or PD as assessed by radiographic scans. Patients with a best response of non-CR/non-PD for patients without measurable disease at baseline are binned with SD. Each line represents one patient with the per cent change of AF relative to baseline (study day 0) plotted for two or three time points. The mutation AF sum is plotted for patients with multiple ESR1 (a) or PIK3CA (b) mutations.