Fig. 5: Neoantigen-specific T cell reactivity and ctDNA dynamics for patients with differential outcomes with neoadjuvant immune checkpoint inhibition.

Overall, neoantigen-specific T cell responses were observed in all patients with pCR and TCR expansions mirrored systemic tumor burden regression. a,b, Patient CGES13 attained a complete pathological response, which was consistent with ctDNA clearance at the preoperative time point (a). In tandem, the neoantigen-specific T cell clone CASWGGGTAAF (CDR3 region) was detected expanding after pulsing with mutation-associated neoantigens contained in pool 7 (b). c,d, Similarly, patient CGES2 showed ctDNA clearance after two cycles of ICI (c), which was reflected in complete pathological response at the time of resection and neoantigen-specific clone expansions for CASSSPETELWDEQFF, CASKGVADTQYF, CASSSRDRPYEQYF and CASSTDILSNYGYTF (d). e,f, In contrast, patient CGES11 showed sustained ctDNA throughout the course of the study (e), which was reflective of a residual tumor of 30% residual tumor at the time of resection. For this patient, there were no neoantigen-specific T cell expansions noted (f).