# CYTO-PV

Source: https://onco.cc/trials/cyto-pv/  
OnCo record `cyto-pv` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CYTO-PV settled the most basic question in PV: keeping the haematocrit under 45 percent gives far fewer serious clots and cardiovascular deaths than a looser target.

## Summary

CYTO-PV randomised 365 adults with polycythaemia vera to a haematocrit target below 45 percent or between 45 and 50 percent, achieved with phlebotomy and hydroxyurea. After a median of 31 months the primary endpoint of cardiovascular death or major thrombosis occurred in 2.7 percent of the low-target group and 9.8 percent of the high-target group (Marchioli and colleagues, New England Journal of Medicine 2013). The result made 45 percent the universal target.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-16
- Tags: polycythaemia-vera; mpn
- Registry id: NCT01645124
- Phase: 3
- Setting: Polycythaemia vera: haematocrit target below 45 percent versus 45 to 50 percent
- Sponsor: GIMEMA (Gruppo Italiano Malattie Ematologiche dell'Adulto)
- Enrolled: 365
- Result: Cardiovascular death or major thrombosis 2.7% vs 9.8% (hazard ratio 3.91 for the higher target).
- Outcomes: Cardiovascular death or major thrombosis: Haematocrit below 45% 2.7% vs Haematocrit 45 to 50% 9.8%

## Sources

- ClinicalTrials.gov NCT01645124: https://clinicaltrials.gov/study/NCT01645124
- NEJM 2013: https://www.nejm.org/doi/full/10.1056/NEJMoa1208500

## Connected records

- cancers: [Myeloproliferative neoplasms (PV, ET, myelofibrosis)](https://onco.cc/cancers/myeloproliferative-neoplasms/), [Polycythaemia vera (PV)](https://onco.cc/cancers/polycythaemia-vera/)
- drugs: [Hydroxyurea (hydroxycarbamide)](https://onco.cc/drugs/hydroxyurea/)
- terms: [Haematocrit](https://onco.cc/terms/haematocrit/), [Phlebotomy (venesection)](https://onco.cc/terms/phlebotomy/)

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