SERPINB3

Overview

SERPINB3 (Serpin Family B Member 3, also known as SCCA1) is a serine protease inhibitor implicated in immune evasion and tumor progression. It has been previously associated with response to anti-CTLA-4 therapy in melanoma. Mutations in SERPINB3 have been observed in the context of immune checkpoint blockade cohorts, where their presence has been linked to a trend toward disease control.

Alterations observed in the corpus

  • Trend toward disease control (5/6 SERPINB3/SERPINB4-mutant patients had CR/PR/SD; p = 0.21, not significant due to small n) in melanoma patients receiving nivolumab; consistent with prior anti-CTLA-4 association reports PMID:29033130.

Cancer types (linked)

  • MEL (Melanoma) — SERPINB3 mutations observed in a nivolumab-treated melanoma cohort with a non-significant trend toward disease control PMID:29033130.

Co-occurrence and mutual exclusivity

  • Co-analyzed with SERPINB4 as a functionally related gene pair; 5/6 patients mutant for either gene achieved disease control on nivolumab PMID:29033130.

Therapeutic relevance

  • SERPINB3 mutations may represent a biomarker for PD-1 blockade response in melanoma, replicating associations previously described for CTLA-4 blockade; cohort size (n=6 mutant patients) insufficient for definitive conclusions PMID:29033130.

Open questions

  • Statistical significance not reached (p = 0.21) due to small cohort; larger prospective validation needed to confirm SERPINB3 mutation as a predictive biomarker for checkpoint blockade PMID:29033130.

Sources

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