Summary

BCMA targeting chimeric antigen receptor (CAR) T cell therapy has shown deep and durable responses in multiple myeloma. However, relapse following therapy is frequently observed, and mechanisms of resistance remain ill-defined. Here, we perform single cell genomic characterization of longitudinal samples from a patient who relapsed after initial CAR T cell treatment with lack of response to retreatment. We report selection, following initial CAR T cell infusion, of a clone with biallelic loss of BCMA acquired by deletion of one allele and a mutation that creates an early stop codon on the second allele. This loss leads to lack of CAR T cell proliferation following the second infusion and is reflected by lack of soluble BCMA in patient serum. Our analysis suggests the need for careful detection of BCMA gene alterations in multiple myeloma cells from relapse following CAR T cell therapy.

Overall design

A single cell cell RNA sequencing has been done for 8 longititunal samples collected from the same patient.

Contributors

Mehmet Kemal Samur 1 2 3, Mariateresa Fulciniti 4, Anil Aktas Samur 5 6, Abdul Hamid Bazarbachi 4 7, Yu-Tzu Tai 4, Rao Prabhala 4 8, Alejandro Alonso 4, Adam S Sperling 4, Timothy Campbell 9, Fabio Petrocca 10, Kristen Hege 9, Shari Kaiser 11, Hervé Avet Loiseau 12, Kenneth C Anderson 4, Nikhil C Munshi 13 14

Contact

nikhil_munshi@dfci.harvard.edu.(Nikhil C Munshi)