# Concurrent Immunoglobulin Light Chain and Transthyretin Cardiac Amyloidosis Patient Treated With Daratumumab and Tafamidis: A Case Report

## TL;DR

A 75-year-old man with two rare heart conditions was successfully treated with a combination of daratumumab and tafamidis.

## Contribution

This case report presents a rare instance of concurrent AL and ATTRwt cardiac amyloidosis treated with a sequential therapy approach.

## Key findings

- The patient had both AL and ATTRwt amyloid deposits confirmed by immunohistochemistry and mass spectrometry.
- Treatment with daratumumab followed by tafamidis was safe and effective for the patient.
- The case highlights the importance of accurate amyloid typing for effective treatment.

## Abstract

Immunoglobulin light chain (AL) and wild‐type transthyretin (ATTRwt) amyloidosis, while sharing similar clinical presentations, require distinct treatments. We report a rare case of a 75‐year‐old man with heart failure diagnosed with concurrent AL and ATTRwt cardiac amyloidosis. Immunohistochemistry and liquid chromatography‐tandem mass spectrometry confirmed both AL and ATTR amyloid deposits in the heart. The patient was safely and effectively treated with daratumumab‐based chemotherapy followed by tafamidis. This case underscores the necessity of precise amyloid typing for tailored therapy, suggesting sequential daratumumab and tafamidis as a viable strategy for this complex overlap.

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