Dosing challenges for chemotherapy and immunotherapy in congenital achondroplasia: a case report and literature review.

INTRODUCTION

Currently, no established guidelines exist for dosing chemotherapy or immunotherapy in patients with achondroplasia.

CASE: A 69-year old female with congenital achondroplasia was diagnosed with stage IV non-small cell lung carcinoma type adenocarcinoma, with high Tumor Mutational Burden and 20% programmed death-ligand 1 expression. The patient received carboplatin dose based on renal function utilizing measured creatinine clearance, pemetrexed based on body surface area and pembrolizumab at a fixed dose of 100mg for body weight <65 kg. The doses of carboplatin and pemetrexed were adjusted after the first cycle based on therapeutic drug monitoring (TDM). The treatment was generally well tolerated, with the exception of grade 2 neutropenia, which resolved after a one-week delay of the third treatment cycle. A favorable clinical response was achieved after four treatment cycles.

CONCLUSION

Given the uncertainty regarding the accuracy of dosing algorithms in patients with congenital achondroplasia, TDM may support dose optimization and attainment of adequate drug exposure.