# Clearing the JAK2 clone in polycythaemia vera: interferon plus mutant-selective inhibitors as a route to treatment-free remission

Source: https://onco.cc/ideas/idea-pv-clone-directed-therapy/  
OnCo record `idea-pv-clone-directed-therapy` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Today's PV drugs control blood counts but leave the mutant cells in place. Interferon is the one treatment that shrinks the clone, and the first JAK2 V617F-selective inhibitors have entered trials; combining the two could aim at molecular remission, the way imatinib did for CML.

## Summary

Polycythaemia vera is driven by a single recurrent mutation in almost every patient, yet no treatment is given with the aim of eliminating it. Ropeginterferon alfa-2b lowers the JAK2 V617F allele burden year on year in PROUD-PV and CONTINUATION-PV, and a fraction of patients reach very low burdens. Ruxolitinib blocks wild-type and mutant JAK2 alike, which limits its dose and spares the clone. Mutant-selective JAK2 V617F inhibitors are now in first-in-human trials. The idea is to test interferon plus a mutant-selective inhibitor against interferon alone with molecular response and progression, not haematocrit, as the endpoints.

## Fields

- Kind: Idea
- Last checked: 2026-09-16
- Tags: polycythaemia-vera; mpn
- Hypothesis: Ropeginterferon alfa-2b combined with a JAK2 V617F-selective inhibitor will produce deep molecular responses (allele burden below 1 percent) in a majority of patients within three years, and deep responders will have a lower rate of progression to myelofibrosis than count-controlled patients.
- Rationale: Interferon's molecular responses are durable and associated with fewer events; complete responders in MAJIC-PV had better event-free survival; CML showed that a single-driver disease can be pushed to treatment-free remission once the clone is suppressed deeply enough.
- Proposed test: A randomised phase 2 in high-risk PV: ropeginterferon with or without a mutant-selective JAK2 inhibitor once phase 1 doses are set, with JAK2 V617F allele burden at 24 and 36 months as the primary endpoint and progression, thrombosis and treatment discontinuation as secondary endpoints.
- Maturity: early-clinical
- Actor: industry

## Connected records

- cancers: [Myeloproliferative neoplasms (PV, ET, myelofibrosis)](https://onco.cc/cancers/myeloproliferative-neoplasms/), [Polycythaemia vera (PV)](https://onco.cc/cancers/polycythaemia-vera/)
- technologies: [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/)
- targets: [JAK2](https://onco.cc/targets/jak2/)
- drugs: [Ropeginterferon alfa-2b](https://onco.cc/drugs/ropeginterferon-alfa-2b/), [Ruxolitinib](https://onco.cc/drugs/ruxolitinib/)
- trials: [MAJIC-PV](https://onco.cc/trials/majic-pv/), [PROUD-PV and CONTINUATION-PV](https://onco.cc/trials/proud-pv/)

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