Polycythemia vera (PV)
JAK2-mutation-driven clonal myeloproliferative neoplasm — JAK2 V617F in ~95% of cases, exon 12 mutations in most of the remainder. Hematology-managed disease; risk-stratified per ELN 2018 / NCCN MPN guidelines (high-risk = age >60 or prior thrombosis history). Standard-of-care: phlebotomy to hematocrit <45% (since 1960s), low-dose aspirin, hydroxyurea (Droxia, Siklos) for high-risk; ruxolitinib (Jakafi JAK1/2 inhibitor) for HU-resistant/intolerant per RESPONSE trials. Paradigm shifts: ropeginterferon alfa-2b (Besremi, FDA November 2021) — first PV-specific disease-modifying agent with documented JAK2 V617F allele burden reduction (molecular response per PROUD-PV / CONTINUATION-PV); rusfertide (PTG-300 hepcidin mimetic) per Phase 3 VERIFY 2024 readouts (iron-restrictive paradigm without phlebotomy iron deficiency). WHO 2022 + ICC 2022 diagnostic criteria. MPN-SAF symptom tracking (pruritus especially aquagenic, fatigue, splenomegaly). The editorial honest answer for this trigger is that no peptide in the Juno library has a defensible discovery-card case — and several have theoretical reasons to AVOID (angiogenic mechanism vs thrombosis-driven morbidity; immune stimulation in clonal myeloid disease).
What changes during this transition
Polycythemia vera is a clonal myeloproliferative neoplasm driven by gain-of-function JAK2 mutations — JAK2 V617F in ~95% of cases, JAK2 exon 12 mutations in most of the remainder. The mutation produces constitutive JAK-STAT signaling in the hematopoietic stem cell compartment, expanding the red cell lineage (often with platelet and granulocyte lineage involvement). Diagnosis follows WHO 2022 and ICC 2022 criteria; risk stratification per ELN 2018 and NCCN MPN guidelines is binary in practice — high-risk is defined as age >60 or prior thrombosis history, low-risk is everyone else. Thrombosis is the dominant morbidity-mortality driver. Standard-of-care is mature and stratified. Phlebotomy to maintain hematocrit <45% has been the foundation since the 1960s. Low-dose aspirin is used for thrombosis prophylaxis unless contraindicated. High-risk disease gets cytoreduction — hydroxyurea (Droxia, Siklos) first-line, ruxolitinib (Jakafi, JAK1/2 inhibitor) for hydroxyurea-resistant or intolerant patients per the RESPONSE trials. The modern paradigm shifts are editorially load-bearing. Ropeginterferon alfa-2b (Besremi, FDA-approved November 2021) is the first PV-specific disease-modifying agent — PROUD-PV and CONTINUATION-PV documented durable hematologic AND molecular response (JAK2 V617F allele burden reduction). Rusfertide (PTG-300, a hepcidin mimetic) with Phase 3 VERIFY trial readouts in 2024 supports iron-restrictive control of erythrocytosis without repeated phlebotomy. Active disease-modification trials include MAJIC-PV, MITHRIDATE, and the MPN-RC series. Anagrelide is used for predominant thrombocytosis. Busulfan is now rare due to leukemogenic risk. Symptom burden tracking uses MPN-SAF Total Symptom Score — pruritus (especially aquagenic, the post-shower itch that is pathognomonic-feeling for patients), fatigue, early satiety from splenomegaly, microvascular symptoms (erythromelalgia, headaches, visual disturbances). Peptides are not part of this toolkit. Several have theoretical reasons to avoid in a clonal MPN: BPC-157 and TB-500 carry angiogenic and endothelial-modulating mechanisms that work in the wrong direction in a disease where thrombosis is the central morbidity driver. Thymosin alpha-1's immune-stimulatory profile has uncharacterized interactions in clonal myeloid disease and overlapping immunomodulation with ropeginterferon if used concurrently — two immunomodulators in a clonal myeloid compartment is not a characterized combination. NMN's mitochondrial framing doesn't translate to PV-meaningful endpoints (hematocrit, JAK2 allele burden, thrombosis risk). Selank's anxiolytic framing speaks to a real symptom of living with PV but doesn't substitute for hematologist communication about modern prognosis (which is dramatically better than older mental models) or for conventional anxiety treatment if it crosses the threshold. Where Juno's library fits — narrowly and with deliberate non-elevation. No peptide has a discovery-card-defensible PV case. The five drafted substrate entries (BPC-157, TB-500, Thymosin alpha-1, NMN, Selank) exist for honest /ask answers when users probe specific compounds. The honest editorial frame: hematology-oncology coordination, JAK2 mutation status + risk stratification + treat-to-target hematocrit + MPN-SAF symptom tracking, and the modern therapeutic ladder (phlebotomy + aspirin + hydroxyurea + ruxolitinib + ropeginterferon + rusfertide) drive outcomes; no peptide in the library substitutes.
Important caveat
PV is hematology-oncology-managed clonal myeloproliferative neoplasm — JAK2 V617F or exon 12 mutation confirmation, WHO 2022 + ICC 2022 diagnostic criteria, ELN 2018 + NCCN MPN risk stratification (binary: age >60 or thrombosis history = high-risk), and MPN-SAF symptom tracking are the workup. No peptide substitutes for this care framework. The standard-of-care: phlebotomy to maintain hematocrit <45% (foundation since 1960s), low-dose aspirin for thrombosis prophylaxis unless contraindicated, hydroxyurea (Droxia, Siklos) for high-risk first-line cytoreduction, ruxolitinib (Jakafi) for hydroxyurea-resistant or intolerant patients per RESPONSE / RESPONSE-2 trials. Paradigm shifts: ropeginterferon alfa-2b (Besremi, FDA November 2021) — the first PV-specific disease-modifying agent per PROUD-PV / CONTINUATION-PV with documented JAK2 V617F allele burden reduction (molecular response); rusfertide (PTG-300 hepcidin mimetic) per Phase 3 VERIFY 2024 readouts for iron-restrictive control without repeated phlebotomy. Anagrelide for predominant thrombocytosis. Active trial programs (MAJIC-PV, MITHRIDATE, MPN-RC) for disease-modification research. No Juno library peptide is surfaced as a PV discovery card. Rule 6 non-propagation is editorially load-bearing on this trigger: BPC-157's Sikiric wound-healing rodent corpus does NOT propagate to clonal MPN, and the angiogenic / VEGF mechanism is theoretically OPPOSED to a thrombosis-driven disease; TB-500's tissue-repair claims operate on endothelial migration and angiogenesis mechanisms that are theoretically OPPOSED to the central thrombotic morbidity driver in PV; Thymosin alpha-1's hepatitis-B Tier 1 registered indication across multiple non-US jurisdictions does NOT propagate to PV, AND the immune-stimulatory mechanism in clonal myeloid disease has uncharacterized effects on clonal dynamics, with specific concern about uncharacterized overlap if used concurrently with ropeginterferon (Besremi); NMN's NAD+/mitochondrial framing does NOT propagate to PV-meaningful endpoints; Selank's Russian GAD/neurasthenia registration does NOT propagate to PV — the anxiety overlay is real but addressing modern prognosis via hematologist conversation, treating aquagenic pruritus through specific channels (antihistamines, SSRIs especially paroxetine, ruxolitinib's documented pruritus reduction, ropeginterferon's symptom-burden improvement), and conventional psychiatry where indicated are the answer. The load-bearing safety thread on this axis: angiogenic / endothelial-modulating peptides (BPC-157, TB-500) in a clonal MPN with thrombosis as the central morbidity-mortality driver are theoretically working in the WRONG direction; disclose any peptide use to your hematologist even for unrelated indications. WADA athletes: BPC-157 (S0) and TB-500 (S2) prohibited at all times. Pregnancy: PV pregnancies are high-risk for thrombotic and obstetric complications and managed by hematology + maternal-fetal medicine; hydroxyurea contraindicated in pregnancy (interferon-based therapy is the preferred cytoreduction option when needed).
Want this list to grow? The library is editorial — if there’s a peptide you think belongs on this page with documented or mechanistically-clear evidence, send us a note with the citation and we’ll review it under the same evidence-tier discipline as every other entry.