Definition

An orally bioavailable modulator of the E3 ubiquitin ligase complex containing cereblon (CRL4-CRBN E3 ubiquitin ligase), with potential immunomodulating and antineoplastic activities. Upon oral administration, cemsidomide specifically binds to cereblon (CRBN), thereby affecting the ubiquitin E3 ligase activity, and targeting certain substrate proteins for ubiquitination. This induces proteasome-mediated degradation of certain transcription factors, including Ikaros (IKZF1) and Aiolos (IKZF3), which are transcriptional repressors in T cells. This reduces the levels of these transcription factors, and modulates the activity of the immune system, which may include the activation of T lymphocytes. This also leads to downregulation of the activity of other proteins, some of which play key roles in the proliferation of certain cancer cell types. CRBN, the substrate recognition component of the CRL4-CRBN E3 ubiquitin ligase complex, plays a key role in the ubiquitination of certain proteins.