{"entity":{"id":"idea-tr1-duffy-null-neutrophil-threshold","kind":"idea","name":"Fix the neutrophil count rule that excludes many people of African ancestry","aka":[],"tldr":"A majority of people of West African ancestry carry the Duffy-null variant, which lowers baseline neutrophil counts without raising infection risk. Trials apply a single neutrophil cut-off that wrongly labels them unfit, so protocols should use Duffy-specific thresholds; Duffy status is a cheap blood test.","summary":"The Duffy-null phenotype (ACKR1 rs2814778 CC), carried by a majority of people of West African ancestry, is associated with lower baseline neutrophil counts without increased infection risk. Protocols would use Duffy-status-specific absolute neutrophil count thresholds (or exclude on infection history rather than ANC alone), and dose-modification rules for neutropenia would be reinterpreted accordingly. Duffy status is a cheap blood test.","asOf":"2026-09-08","links":[{"label":"Bottleneck evidence (Trials do not represent the people who get cancer): Loree et al., Disparity of race reporting and representation in trials leading to cancer drug approvals (JAMA Oncology 2019)","url":"https://doi.org/10.1001/jamaoncol.2019.1870"}],"tags":[],"related":[],"cancers":["prostate","multiple-myeloma","tnbc"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":["b-trial-diversity","b-trial-enrolment"],"keyPapers":["paper-loree-jama-oncol"],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"Adopting Duffy-aware ANC thresholds will remove a leading cause of screen failure among Black patients in oncology trials and will not increase febrile neutropenia among those enrolled under the adjusted threshold.","rationale":"Retrospective analyses attribute a substantial share of Black patients' trial ineligibility and chemotherapy dose reductions to the standard ANC cut-off, and the Duffy-null association with benign neutropenia is well established in haematology.","test":"A sponsor adopts Duffy-aware thresholds across its solid-tumour trials for two years; compare Black patient screen-failure rates and febrile neutropenia among those newly eligible against prior protocols.","maturity":"early-clinical","actor":"industry","cost":"small","horizonYears":1},"route":"/ideas/idea-tr1-duffy-null-neutrophil-threshold/","neighbours":{"cancer":[{"id":"multiple-myeloma","kind":"cancer","name":"Multiple myeloma","route":"/cancers/multiple-myeloma/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"bottleneck":[{"id":"b-trial-diversity","kind":"bottleneck","name":"Trials do not represent the people who get cancer","route":"/bottlenecks/b-trial-diversity/"},{"id":"b-trial-enrolment","kind":"bottleneck","name":"Trials enrol too few, too slowly","route":"/bottlenecks/b-trial-enrolment/"}],"paper":[{"id":"paper-loree-jama-oncol","kind":"paper","name":"Disparity of Race Reporting and Representation in Clinical Trials Leading to Cancer Drug Approvals From 2008 to 2018","route":"/key-papers/paper-loree-jama-oncol/"}]}}