The impact of bridging therapy (BT) administered between leukapheresis and chimeric antigen receptor (CAR) T-cell therapy for large B-cell lymphoma (LBCL) is unclear. We evaluated the influence of BT (systemic therapy [ST], radiation therapy [RT], or combined-modality therapy [CMT]) on outcomes of 148 LBCL patients who underwent leukapheresis for planned axicabtagene ciloleucel (axi-cel) infusion. The 55% (n = 81) of patients who received BT were more likely to have international prognostic index (IPI) score ≥3 (P ≤ .01), bulky disease (P = .01), and elevated lactate dehydrogenase (LDH; P ≤ .01). The 1-year progression-free (PFS) and overall survival (OS) rates were 40% and 65% in non-BT patients vs 21% and 48% in BT patients (P = .01 and .05, respectively). Twenty-four patients (16%) did not receive axi-cel, most commonly because of lymphoma progression (88%), despite 80% (n = 19) receiving BT. Among 124 patients who received axi-cel, 50% (n = 62) received BT with ST (n = 45), RT (n = 11), or CMT (n = 6); 1-year PFS and OS rates were not significantly different between BT and non-BT cohorts (P = .06 and .21, respectively). There was no difference in proportion of patients with IPI ≥3, limited-stage disease, or elevated LDH between ST, RT, and CMT groups. Compared with non-BT patients, 1-year PFS was inferior for ST-bridged patients (P = .01). RT-bridged patients had improved PFS compared with ST-bridged patients (P = .05). Despite the poor prognosis associated with requiring BT, RT can be an effective bridging strategy. Future studies are necessary to identify strategies that may improve access to CAR T-cell therapy and outcomes.

Milgrom SA, et al. J Cardiovasc Imaging. 2019 Apr;27:e38. https://doi.org/10.4250/jcvi.2019.27.e38

Standard treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (NACRT), followed by surgical resection. However, >70% of patients do not achieve a complete pathological response and have higher rates of relapse and death. There are no validated pre- or on-treatment factors that predict response to NACRT besides tumour stage and size. We characterised the response of 33 LARC patients to NACRT, collected tumour samples from patients prior to, during and after NACRT, and performed whole exome, transcriptome and high-depth targeted sequencing. The pre-treatment LARC genome was not predictive of response to NACRT. However, in line with the increasing recognition of microbial influence in cancer, RNA analysis of pre-treatment tumours suggested a greater abundance of Fusobacteria in intermediate and poor responders. In addition, we investigated tumour heterogeneity and evolution in response to NACRT. While matched pre-treatment, on-treatment and post-treatment tumours revealed minimal genome evolution overall, we identified cases in which microsatellite instability developed or was selected for during NACRT. Recent research has suggested a role for adaptive mutability to targeted therapy in colorectal cancer cells. We provide preliminary evidence of selection for mismatch repair deficiency in response to NACRT. Furthermore, pre-NACRT genomic landscapes do not predict treatment response but pre-NACRT microbiome characteristics may be informative.