Niraparib (Zejula)

How Medicare covers it

Part D (forms used at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Maintenance treatment of advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer in adults who are in a complete or partial response to platinum-based chemotherapy: (1) first-line maintenance when the cancer is HRD-positive (a deleterious or suspected deleterious BRCA mutation and/or genomic instability), and (2) maintenance of recurrent cancer with a deleterious or suspected deleterious germline BRCA mutation. Patients are selected using an FDA-authorized companion diagnostic test.

What it is for, in depth

Zejula is not a first treatment for ovarian cancer — it is the maintenance medicine taken after platinum chemotherapy has already shrunk the cancer, to keep it from coming back for as long as possible. It fits two places in the treatment path: after first-line chemotherapy, for advanced ovarian, fallopian tube, or primary peritoneal cancer that tests HRD-positive (a BRCA mutation and/or genomic instability on an FDA-authorized test); and after chemotherapy for recurrent cancer that carries an inherited (germline) BRCA mutation. Testing comes first — the label requires selecting patients with the companion diagnostic. It comes as 100 mg, 200 mg, and 300 mg tablets (the three strengths in this package), so the 200 mg and 300 mg daily doses and step-down dose reductions can all be built from them.

How it works

Niraparib blocks PARP enzymes (PARP-1 and PARP-2), which cancer cells use to repair damaged DNA. Blocking repair makes DNA damage build up in the cancer cells until they die; the effect is strongest in tumors that already have broken repair systems, such as BRCA-mutated or HRD-positive cancers.

How it is taken

Tablets by mouth once a day, with or without food, swallowed whole — do not chew, crush, or split. First-line maintenance dose is set by weight and platelet count: 200 mg a day if under 77 kg (170 lbs) or platelets under 150,000/mcL, otherwise 300 mg a day. Recurrent germline BRCA maintenance dose is 300 mg a day. Treatment continues until the cancer progresses or side effects become unacceptable; taking it at bedtime may help with nausea.

Common side effects

The most common reactions (at least 10%) were nausea, low platelets, anemia, fatigue, constipation, muscle and joint pain, abdominal pain, vomiting, low white blood cells, decreased appetite, insomnia, headache, breathlessness, rash, diarrhea, high blood pressure, cough, dizziness, kidney injury, urinary tract infection, and low magnesium.

Serious warnings

MDS/AML — a serious bone-marrow cancer — has occurred in patients treated with Zejula and some cases were fatal; the drug is stopped if MDS/AML is confirmed. Bone marrow suppression is common: blood counts are checked weekly for the first month, monthly for the next 11 months, then periodically. Blood pressure and heart rate can rise and are monitored weekly for the first 2 months, then monthly for the first year. PRES (a reversible brain swelling syndrome) has occurred and requires stopping the drug. Zejula can cause fetal harm, so effective contraception is required.

Who should be careful

Treatment requires an FDA-authorized test showing HRD-positive or germline BRCA-mutated status first. Blood counts, blood pressure, and heart rate need regular monitoring. The dose is reduced to 200 mg a day in moderate liver impairment. Females of reproductive potential must use effective contraception because of fetal-harm risk.

Major interactions

The Zejula label lists no major drug-interaction combinations that change dosing; its labeled cautions center on blood counts, blood pressure, and pregnancy. (The separate Akeega combination tablet, which pairs niraparib with abiraterone, is a different product and is not part of this package.)

Cost and saving notes

This is a Tier 5 specialty drug in most plans: Medicare's 2027 Part D out-of-pocket cap ($2,400 for the year) and Extra Help (the Part D low-income subsidy) are the main Medicare cost routes.

Why it is in its tier

Niraparib (Zejula) sits on Tier 5 — the specialty tier — in 96.91% of the plans that list it, and every Part D plan in the 2027 file lists it (100%). Tier 5 is the highest tier: patients usually pay a percentage of the cost (coinsurance) rather than a flat copay. The data-visible drivers match that placement: Zejula is a brand-only cancer medicine with no generic, and CMS dashboard average spending is about $111,182 per beneficiary for 2024 — a very high-cost drug, and high cost is the defining feature of specialty-tier placement. The tier shown is the most common one; a small share of plans file it on Tier 4 or Tier 1, and individual plans vary.

Sources

• ZEJULA (niraparib) tablet, film coated — DailyMed
• MedlinePlus — Niraparib

What official patient guides say

One thing to know first: the MedlinePlus page describes niraparib as capsules, while this package covers the Zejula tablets, so the daily routine below is the routine as that page states it. In daily life, niraparib is taken by mouth once a day, at about the same time every day, with or without food. If it makes you feel sick to your stomach, the page says you can take it once a day at bedtime. Swallow it whole and do not open, chew, or dissolve it. If you throw up after a dose, do not take another dose — just go back to your regular schedule. If you forget a dose, skip the missed dose and go back to your regular schedule. Do not take a double dose to make up for a missed dose. Keep it in the container it came in, tightly closed, at room temperature and away from extra heat and moisture (not in the bathroom), and out of the sight and reach of children. Get rid of medicine you no longer need through a medicine take-back program and do not flush it down the toilet.

Source: MedlinePlus — Niraparib

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-08

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 5,495 list Niraparib (Zejula) — 100% of plans. Most of those plans put it on Tier 5: 5,325 plans, 96.9% of the plans that list it. Other plans place it on Tier 1 (123 plans), Tier 4 (46 plans) or Tier 2 (1 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 5; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 5; Aetna Medicare Value Plus (PPO) puts it on Tier 5. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan';s deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.