Prescribing guide
Mimrylo (rusfertide)Dosing, titration to hematocrit below 45%, CBC monitoring and access for polycythemia veraFor prescribers and their offices treating polycythemia vera: what the pharmacy needs before it ships, what the prior authorization wants documented, the titration and the monitoring the label requires.
Label updated. The FDA's label database lists a Mimrylo label dated November 2, 2026, newer than the August 28, 2026 label this guide is built from. Trial Friend is rechecking this guide; until then the current label governs: current label on DailyMed.
Dispensing gate
No REMS; pregnancy testing recommended for females of reproductive potential, injection training before initiation, the Here2Assist enrollment form with original prescriber and patient signatures faxed to 1-844-269-3038 (the form's prescription is valid only by fax), and routing to Biologics by McKesson, Onco360 or in-office dispensing.
Example PA threshold
No public payer policy found as of November 9, 2026; label indication is erythrocytosis in adults with PV; VERIFY enrolled patients with at least 3 phlebotomies in 28 weeks or 5 in a year despite standard care.
Monitoring
CBC every 2 to 4 weeks after initiation and during dose modifications, or as clinically indicated; titrate to hematocrit below 45%; platelets generally plateau by week 8.
Support line
Takeda Oncology Here2Assist, 1-844-817-6468, Option 2, Monday to Friday 8 AM to 8 PM Eastern; fax 1-844-269-3038; benefits verification within 1 business day; free nurse-led injection training; co-pay as little as $0 for commercial plans; PAP; a 2-month Bridge Program for patients already on therapy.
Give your patient their plan
A one-page handout for starting Mimrylo, in plain language: what the first fill waits on, the first dates, who will call and the symptoms to report, with blank lines for the start date and your office's number. The link opens the patient's full first 90 days page, where their dates become calendar entries.
trialfriend.com/p/mimryloBefore the first fill: REMS, labs and enrollment
The steps that the pharmacy, the REMS or the drugmaker's program will wait on, in the order they usually need to happen. A first fill of a specialty drug most often stalls on one of these rather than on the plan.
| Step | What it requires | Source |
|---|---|---|
| Confirm the indication | Erythrocytosis in adults with polycythemia vera. Safety and effectiveness in pediatric patients are not established. | FDA label |
| Pregnancy testing and contraception | Pregnancy testing is recommended for females of reproductive potential before treatment. Advise effective contraception during treatment and for at least 30 days after the final dose, and no breastfeeding during treatment and for 30 days after, citing possible impaired iron absorption in the infant. | FDA label |
| Train before day 1 | Section 2.4: before initiation, show the patient or caregiver how to prepare and inject subcutaneously into the abdomen, thigh or upper arm. The upper arm is for caregiver administration only. | FDA label |
| Nurse-led training | Here2Assist provides free injection training to all enrolled Mimrylo patients, virtual or in person on request, covering technique, site rotation, disposal and side-effect management. | Here2Assist enrollment form |
| Enroll in Here2Assist | Fax the enrollment form to 1-844-269-3038 or enroll online. Original prescriber and patient (or legal representative) signatures are required; stamps are refused. The form asks for the ICD-10 code, a pharmacy preference and both sides of the insurance cards. | Here2Assist enrollment form |
| Write the prescription | The form lists 9.5, 19, 28, 41, 54, 69, 82, 95 and 108mg, with fields for directions, dispense quantity and refills. It restates a 19mg weekly start, an 82mg maximum daily dose and a 108mg maximum weekly dose. The prescription is valid only if received by fax. | Here2Assist enrollment form |
| Route the prescription | Biologics by McKesson 1-800-850-4306 or Onco360 Oncology Pharmacy 1-877-662-6633. For in-office dispensing, contact the specialty distributor or Here2Assist at 1-844-817-6468, Option 5. | Here2Assist pharmacies |
| Benefits verification and PA | Within 1 business day of enrollment, with out-of-pocket costs, exclusions, PA and appeal processes and in-network specialty pharmacies. Here2Assist tracks PA status and expirations but does not complete forms or submit PAs or appeals. | Here2Assist coverage |
Prior authorization criteria and what to document
No public payer policy with Mimrylo criteria was found as of November 9, 2026. On November 9, 2026 we searched public policies from Express Scripts, FEP Blue, Aetna, Cigna and others and found no Mimrylo criteria. The FDA approved Mimrylo on August 28, 2026, a little over 2 months before that search. Until plans publish their own rules, Takeda's Nurse Navigators can explain what a particular plan asks for after the benefits check.
| Element | What the checklist lists | In the chart | Source |
|---|---|---|---|
| Payer criteria | No public payer policy with Mimrylo criteria found as of November 9, 2026 | Request the plan's PA requirements from Here2Assist after the benefits verification | Here2Assist coverage |
| Indication | Erythrocytosis in adults with PV; pediatric use not established | Diagnosis and date of birth on the request | FDA label |
| Medical necessity | The enrollment form's statement of medical necessity asks for the ICD-10 code | Enrollment form, page 2 | Here2Assist enrollment form |
| Phlebotomy history (trial reference) | VERIFY required at least 3 phlebotomies in the 28 weeks or 5 in the year before randomization for inadequate hematocrit control on standard care; a reference point, not a published payer criterion | Phlebotomy dates and hematocrit values | FDA label |
| Background therapy (trial reference) | At randomization: phlebotomy only 44.7%, plus hydroxyurea 38.9%, interferon 13.3%, ruxolitinib 2.4%, combination 0.6% | Current and prior cytoreductive therapy with dates | FDA label |
| Hematocrit | Baseline mean 42.2% (Mimrylo) and 42.4% (placebo); titration target below 45% | Recent CBC with date | FDA label |
| Appeals | Sample Letter of Medical Necessity and Sample Letter of Appeal templates are downloadable; expedited medical necessity requests are suggested for patients needing immediate attention | Here2Assist HCP coverage page | Here2Assist coverage |
Mimrylo dosing and titration
| When | Label | Source |
|---|---|---|
| Day 1 | 19mg subcutaneously once weekly. One single-dose vial of lyophilized powder per carton, co-packaged with a diluent prefilled syringe. | FDA label |
| Increase | After at least 2 weeks at the current dose, 1 step: 9.5 to 19, 19 to 28, 28 to 41, 41 to 54, 54 to 69, 69 to 82, 82 to 95, 95 to 108mg, to reduce or maintain hematocrit below 45%. | FDA label |
| Decrease | 1 step for grade 2 or higher anemia or drug-related grade 3 or higher toxicity; from 9.5mg, discontinue. | FDA label |
| 69 and 82mg | 2 injections on the same day: 28mg plus 41mg, or 41mg plus 41mg. | FDA label |
| 95 and 108mg | Day 1: 54mg; day 4 or 5: 41mg or 54mg. The Patient Information limits patients to 2 injections a day. | FDA label |
| Missed dose, weekly | 1 to 4 days late: inject immediately, resume the schedule. More than 4 days: inject immediately, next injection 3 days later, then resume. | FDA label |
| Missed dose, twice weekly | 1 to 2 days late: inject immediately, next injection 3 days later, then resume. More than 2 days: skip and continue the schedule. | FDA label |
| Preparation | Reconstitute with the full diluent syringe via the vial adapter, swirl about 2 minutes without shaking, settle about 1 minute; clear, colorless solution. Administer within 4 hours at 20 to 25°C, otherwise discard. | FDA label |
| Storage | 20 to 25°C (68 to 77°F) in the original carton to protect from light; do not freeze. Cap colors: 9.5mg blue, 19mg lime, 28mg burgundy, 41mg yellow, 54mg white. | FDA label |
| Renal and hepatic | No clinically meaningful AUC difference in severe renal impairment (eGFR under 30) or moderate hepatic impairment (Child-Pugh B) after 19mg; not studied in Child-Pugh C. No dose adjustment is stated. | FDA label |
| Dating period | 24 months from manufacture at 20 to 25°C. | FDA letter |
Monitoring the Mimrylo label requires
| When | What | What the label says to do with it | Source |
|---|---|---|---|
| After initiation and dose changes | CBC every 2 to 4 weeks, or as clinically indicated | Section 2.2 and 5.1; titrate to hematocrit below 45% | FDA label |
| Weeks 0 to 8 | Platelets | Mean rise 31% within 4 weeks, plateau by week 8; above 600 x 10⁹/L in 36%, above 1,000 x 10⁹/L in 6%; discontinued for platelets in 1%. May require starting or changing cytoreductive therapy, or a Mimrylo dose change or discontinuation | FDA label |
| Any time | Signs of bleeding or thrombosis: unusual bruising or bleeding, chest pain, dyspnea, leg pain or swelling, sudden severe headache | Counsel patients to contact the prescriber (section 17) | FDA label |
| Weeks 0 to 32 | Anemia 16% against 4.1%; dyspnea 8% against 1.4%; thrombocytosis 8% against 0.7% | Dose reduction for anemia in 10%; 1 serious anemia (0.4%) | FDA label |
| Each injection | Injection site reactions, 56% against 33% in weeks 0 to 32; erythema 27%, pruritus 17%, pain 15%, swelling 8% in VERIFY | 2 grade 3 events; 0.7% discontinued. Ice, topical corticosteroids, antihistamines or analgesics as needed | FDA label |
| Iron stores | Mean ferritin 21mcg/L at baseline, 124mcg/L at week 32, 174mcg/L at week 52 | Pharmacodynamic finding; no label monitoring instruction | FDA label |
| Immunogenicity | Anti-drug antibodies in 34% (97 of 282); 36% of those neutralizing, 12% cross-reactive to human hepcidin | No apparent effect on PK, efficacy or safety in VERIFY | FDA label |
| Postmarketing | Required study of long-term safety with at least 3 years of follow-up: thrombocytosis, thromboembolism, transformation to myelofibrosis or AML, JAK2 allele burden, cytoreductive therapy use | Final report due 06/2029 | FDA letter |
Mimrylo drug interactions and contraindications
| Label category | Agents and what the label says | Source |
|---|---|---|
| Section 7 | The label has no drug interactions section | FDA label |
| CYP enzymes | In vitro, no inhibition of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 or 3A at clinically relevant concentrations, and no induction of CYP1A2, 2B6 or 3A | FDA label |
| Transporters | Not a substrate or inhibitor of BCRP, BSEP, MATE1, MATE2K, OATP1B1, OATP1B3, OAT1, OAT3, OCT1, OCT2 or P-gp | FDA label |
| Background PV therapy | Studied added to phlebotomy alone or with hydroxyurea, interferon or ruxolitinib; platelet rises may prompt cytoreductive therapy changes | FDA label |
| QT | No clinically significant QTc prolongation at 1.3 times the Cmax of 108mg weekly | FDA label |
| Lactation | Not recommended during treatment and for 30 days after the final dose | FDA label |
Why a first fill stalls, and the fix
- Prior authorization pending or deniedWe found no public insurer policy for Mimrylo as of November 9, 2026. A Nurse Navigator explains the plan's prior authorization process and keeps the office and the pharmacy updated. Takeda offers sample letters of medical necessity and appeal, which the office fills in and submits itself.
- The enrollment form was not acceptedThe form needs original signatures from the prescriber and the patient or a legal representative, and stamped signatures are refused. The prescription on the form is valid only if it arrives by fax, at 1-844-269-3038.
- The prescription went to the wrong pharmacyTakeda lists Biologics by McKesson (1-800-850-4306) and Onco360 Oncology Pharmacy (1-877-662-6633) for Mimrylo. In-office dispensing is arranged through a specialty distributor or Here2Assist, Option 5.
- A copay you cannot payWith commercial insurance, the Takeda Oncology Co-Pay Assistance Program may lower the cost to as little as $0 per prescription. You must be at least 18, live in the United States or a US territory, and meet the program's other terms.
- Medicare, Medicaid, TRICARE or VA coverageThe copay program's terms exclude anyone whose Mimrylo claims can be paid by a state or federal program. Takeda points these patients to Medicare's Extra Help, the Patient Advocate Foundation, the American Cancer Society and CancerCare.
- No insurance, or the plan will not cover itThe Takeda Oncology Patient Assistance Program may provide Mimrylo at no cost to people who meet its financial and coverage criteria. To apply, you first enroll in Here2Assist and then submit a separate application.
- A gap in commercial coverage after startingThe Bridge Program offers Mimrylo at no cost for up to 2 months during a temporary gap, such as a job loss. It is only for people already taking Mimrylo whose coverage came from a commercial plan.
Takeda Oncology Here2Assist (MIMRYLO Patient Support)
- A Nurse Navigator who welcomes you, ships a Welcome Kit, checks your insurance benefits and out-of-pocket costs, and tracks any prior authorization or appeal
- Free one-on-one injection training from a registered nurse for you or a care partner, by video or in person on request Here2Assist enrollment form
- Co-pay help for commercial insurance, as little as $0 per prescription for eligible patients 18 and older, not for Medicare, Medicaid, TRICARE, VA, DoD or state programs MIMRYLO Patient Support
- The Takeda Oncology Patient Assistance Program, Mimrylo at no cost for eligible people who are uninsured or whose plan does not cover it, after an application Here2Assist financial help
- A Bridge Program, Mimrylo at no cost for up to 2 months during a temporary gap in commercial coverage, for people already taking it
- Shipping from a specialty pharmacy, or pickup at the doctor's office where in-office dispensing is available, plus optional text updates and refill reminders
- Nurse Navigator check-ins every 8 weeks after enrollment Here2Assist FAQ
Questions prescribers' offices ask about Mimrylo
What is the Mimrylo starting dose and titration?
19mg subcutaneously once weekly, per the August 2026 label, within a weekly range of 9.5mg to 108mg. After at least 2 weeks at the current dose, increase one step (9.5, 19, 28, 41, 54, 69, 82, 95, 108mg) to reduce or maintain hematocrit below 45%.
What monitoring does the Mimrylo label require?
A CBC every 2 to 4 weeks after initiation and during dose modifications, or as clinically indicated, per the August 2026 label. Platelets rose a mean 31% within 4 weeks and generally plateaued by week 8; 36% of patients exceeded 600 x 10⁹/L and 6% exceeded 1,000 x 10⁹/L.
When is the Mimrylo dose reduced?
By 1 step for grade 2 or higher anemia or a drug-related grade 3 or higher toxicity, per the August 2026 label; at 9.5mg the label says to discontinue. In VERIFY, anemia led to dose reduction in 28 patients (10%).
Does Mimrylo have a REMS, boxed warning or contraindications?
The August 2026 label lists 0 contraindications and carries no boxed warning, and the August 28, 2026 approval letter requires no REMS. Warnings are new or worsening thrombocytosis, injection site reactions and embryo-fetal toxicity.
What do insurers ask for to approve Mimrylo?
As of November 9, 2026 we found 0 public payer policies with Mimrylo criteria, so the August 2026 label's indication, erythrocytosis in adults with PV, is the fixed reference. Here2Assist runs a benefits verification within 1 business day of enrollment, explains the plan's PA requirements and offers sample letters of medical necessity and appeal; it does not submit PAs or appeals.
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Sources
- MIMRYLO (rusfertide) for injection, for subcutaneous use, prescribing information, Patient Information and Instructions for Use, Revised 8/2026, Takeda Pharmaceuticals America, via DailyMed and openFDA, 2026-08-28.
- NDA 220605 approval letter, Mimrylo (rusfertide) for injection, FDA, 2026-08-28.
- Drugs@FDA: New Drug Application (NDA) 220605, MIMRYLO, FDA, 2026-11-09.
- SPL history, MIMRYLO (RUSFERTIDE) KIT [TAKEDA PHARMACEUTICALS AMERICA, INC.], U.S. National Library of Medicine, DailyMed, 2026-11-04.
- MIMRYLO™ Patient Support Program, Takeda, 2026-11-09.
- MIMRYLO™ (rusfertide) Getting Started │ Takeda Oncology Here2Assist®, Takeda, 2026-11-09.
- MIMRYLO™ (rusfertide) Financial Assistance │ Takeda Oncology Here2Assist®, Takeda, 2026-11-09.
- MIMRYLO™ (rusfertide) FAQ │ Takeda Oncology Here2Assist®, Takeda, 2026-11-09.
- MIMRYLO™ (rusfertide) HCP Understanding Coverage │ Takeda Oncology Here2Assist®, Takeda, 2026-11-09.
- MIMRYLO™ (rusfertide) HCP Distribution and Fulfillment │ Takeda Oncology Here2Assist®, Takeda, 2026-11-09.
- MIMRYLO (rusfertide) Takeda Oncology Here2Assist Enrollment Form, 08/26 US-RUS-0191, Takeda, 2026-11-09.
A reference drawn from the August 28, 2026 label, the drugmaker's published program and one public insurer policy shown as an example, checked on November 9, 2026. Labels and policies change; the label on DailyMed and the plan's current policy govern. Trial Friend is not a medical provider. It reports what these documents say and does not judge whether a drug is safe or right for any patient; that is the prescriber's decision. Not a substitute for the prescribing information.