# Caution: T-cell redirectors and infections

Source: https://onco.cc/pairings/bispecific-infection-prophylaxis/  
OnCo record `bispecific-infection-prophylaxis` (Pairing). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Myeloma bispecifics and CAR-T suppress antibody production so profoundly that infections, not the cancer, became a leading cause of death in early trials.

## Summary

This caution pairing records that BCMA-directed T-cell redirectors in multiple myeloma, teclistamab, elranatamab and linvoseltamab, suppress antibody production so profoundly that infections rather than the cancer became a leading cause of death in early trials. BCMA is expressed on normal plasma cells, and continuous T-cell engagement causes T-cell exhaustion and deep humoral immunodeficiency; in MajesTEC-1 severe infections were frequent, including fatal COVID-19 and pneumonia, and hypogammaglobulinaemia was almost universal. The pattern held across MajesTEC-1, MagnetisMM-3 and LINKER-MM1 and is less marked with GPRC5D agents. Immunoglobulin replacement, antiviral and PJP prophylaxis, vaccination, and response-adapted dosing every two to four weeks are now standard.

## Fields

- Kind: Pairing
- Last checked: 2026-09-07
- Pairs: Teclistamab + Cytokine release syndrome (CRS)
- Type: caution
- Rationale: BCMA is expressed on normal plasma cells; continuous T-cell engagement causes T-cell exhaustion and profound humoral immunodeficiency.
- Evidence: Consistent across MajesTEC-1, MagnetisMM-3, LINKER-MM1; lower with GPRC5D agents.

## Sources

- MajesTEC-1: teclistamab, an off-the-shelf BCMA bispecific antibody, in heavily pretreated myeloma (New England Journal of Medicine 2022): https://doi.org/10.1056/NEJMoa2203478

## Connected records

- cancers: [Multiple myeloma](https://onco.cc/cancers/multiple-myeloma/), [Relapsed or refractory multiple myeloma](https://onco.cc/cancers/myeloma-relapsed-refractory/)
- drugs: [Elranatamab](https://onco.cc/drugs/elranatamab/), [Linvoseltamab](https://onco.cc/drugs/linvoseltamab/), [Teclistamab](https://onco.cc/drugs/teclistamab/)
- terms: [Cytokine release syndrome (CRS)](https://onco.cc/terms/crs/)
- key papers: [MagnetisMM-3: elranatamab, a second BCMA bispecific, with a switch to fortnightly dosing after response](https://onco.cc/key-papers/paper-magnetismm-3-elranatamab-natmed-2023/), [MajesTEC-1: teclistamab, an off-the-shelf BCMA bispecific antibody, in heavily pretreated myeloma](https://onco.cc/key-papers/paper-majestec-1-teclistamab-nejm-2022/)

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