CHM stands for the Commission on Human Medicines. The CHM monitor the safety of medicines and encourage healthcare professionals and patients to report all suspected adverse drug reactions using the Yellow Card Scheme. The CHM used to be called the CSM - the Committee on Safety of Medicines. Found on http://www.medicines.org.uk/emc/glossary
Commission on Human Medicines. An advisory non-departmental public body that advises ministers on the safety, efficacy and quality of medicinal products. Found on https://post.parliament.uk/covid-19-glossary/