Medications
Afatinib (Gilotrif)
A once-daily tablet (Gilotrif) for non-small cell lung cancer carrying EGFR changes (first treatment) and for squamous lung cancer after platinum chemotherapy; it permanently blocks the ErbB family of growth signals (EGFR, HER2, HER4).
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.
| Coverage details | |
|---|---|
| Part B status | No afatinib row in the CMS Part B Spending by Drug HCPCS file (RY26, data through 2024) — no J-code basis; coverage path is Part D. |
| Medicare Advantage | Most Medicare Advantage plans that include drug coverage (MAPD plans) use the same formulary-and-tier system; the plan's own drug list decides coverage and copay — check the plan's formulary. |
| Medicare Supplement (Medigap) | Medicare Supplement (Medigap) plans sold today do not include prescription drug coverage; drug coverage comes from Part D or an MAPD plan. |
What it treats
Metastatic non-small cell lung cancer (NSCLC) in two settings: as first-line treatment when the tumor has non-resistant EGFR mutations found by an FDA-approved test, and for metastatic squamous NSCLC that is progressing after platinum-based chemotherapy. Brand name Gilotrif.
What it is for, in depth
Gilotrif (afatinib) is a targeted pill for metastatic non-small cell lung cancer, a lung cancer that has spread. Its first use is as the first treatment for patients whose tumors carry non-resistant EGFR mutations — most often exon 19 deletions or the exon 21 L858R change — confirmed by an FDA-approved test, so patients are selected by tumor testing before starting. Its second use is for metastatic squamous non-small cell lung cancer that keeps growing after platinum-based chemotherapy, which makes it a later-line option there. The usual dose is one 40 mg tablet by mouth once a day on an empty stomach, continued until the cancer progresses or side effects become intolerable, and it also comes in 30 mg and 20 mg tablets so the dose can be lowered when needed.
How it works
Afatinib is a kinase inhibitor that permanently (irreversibly) binds to the kinase parts of EGFR (ErbB1), HER2 (ErbB2), and HER4 (ErbB4) and blocks their tyrosine kinase activity, which turns down ErbB signaling that certain lung cancers use to grow. The most common non-resistant EGFR mutations it targets are exon 21 L858R substitutions and exon 19 deletions. MedlinePlus describes it the same way: it blocks a naturally occurring substance that cancer cells may need to multiply.
How it is taken
40 mg by mouth once a day, on an empty stomach — at least 1 hour before or 2 hours after a meal — until the cancer progresses or the side effects can no longer be tolerated. Do not take a missed dose within 12 hours of the next dose. People with pre-existing severe kidney impairment start at 30 mg once a day, and doses are lowered in 10 mg steps when serious side effects occur.
Common side effects
In the main EGFR-mutation trial (LUX-Lung 3), the most common side effects in Gilotrif patients were diarrhea (96%), rash and acne-like dermatitis (90%), mouth sores (stomatitis, 71%), nail infection and inflammation (paronychia, 58%), dry skin (31%), decreased appetite (29%), nausea (25%), vomiting (23%), itching (21%), nosebleeds (17%), weight loss (17%), bladder infection symptoms (cystitis, 13%), fever (12%), lip inflammation (cheilitis, 12%), runny nose (11%), and conjunctivitis (11%). Lab changes included raised liver enzymes (ALT and AST) and lowered creatinine clearance.
Serious warnings
Warnings include: severe diarrhea that can cause dehydration and kidney damage and has sometimes been fatal, so patients are given an anti-diarrheal such as loperamide to start at the first loose stool; serious blistering and peeling skin disorders, including postmarketing reports of Stevens-Johnson syndrome and toxic epidermal necrolysis; interstitial lung disease (lung inflammation, 1.6%, sometimes fatal); liver toxicity, with periodic liver testing; gastrointestinal perforation (a tear in the stomach or intestine, sometimes fatal), with higher risk in people also taking corticosteroids, NSAIDs, or anti-angiogenic drugs or who have ulcers, diverticular disease, or bowel metastases; keratitis (eye inflammation); and harm to an unborn baby. Treatment is withheld or stopped for severe reactions, and stopped permanently for confirmed interstitial lung disease, gastrointestinal perforation, severe liver impairment, life-threatening blistering skin lesions, or persistent ulcerative keratitis.
Who should be careful
The label lists no contraindications. People who could become pregnant must use effective contraception during treatment and for at least 2 weeks after the last dose, because Gilotrif can harm an unborn baby, and they must not breastfeed during treatment and for 2 weeks after the last dose. People with severe kidney impairment use the lower 30 mg dose. Use with caution in people with a history of keratitis, ulcerative keratitis, or severe dry eye, and in contact lens wearers, and check liver tests regularly during treatment.
Major interactions
Afatinib levels are changed by P-glycoprotein (P-gp) drugs: with a P-gp inhibitor, the Gilotrif daily dose is reduced by 10 mg if it is not tolerated; with a P-gp inducer used long-term, the daily dose is increased by 10 mg as tolerated, then returned to the previous dose 2 to 3 days after the inducer is stopped. MedlinePlus also flags St. John's wort as interacting with afatinib.
Cost and saving notes
This drug is usually covered under Medicare Part D, often through a specialty pharmacy with prior authorization. If your cost is high, ask your plan about a tier exception. If you have limited income, the Extra Help (Low-Income Subsidy) program can lower your Part D premiums and drug costs. In 2027, your total yearly out-of-pocket spending on Part D drugs is capped at $2,400, and you can ask your plan to spread those costs out in monthly payments through the Medicare Prescription Payment Plan. The maker may also offer a patient support program.
Why it is in its tier
Afatinib (Gilotrif) sits on Tier 5 in 96.91% of the plans that list it (5325 of 5495 listing plans). Tier 5 is the specialty tier — instead of a flat copay, patients usually pay a percentage of the drug's cost (coinsurance), which is why specialty drugs feel expensive even with coverage. The data-visible drivers: It is a brand-only product with no generic version in the formulary data, and the CMS dashboard puts its average Part D spending at about $65,026 per beneficiary for 2024 — among the highest-cost drugs in the program, which matches where plans place it. It is listed by 100.0% of Part D plans. The tier shown is the most common one; individual plans vary.
Sources
- GILOTRIF (AFATINIB) TABLET, FILM COATED [BOEHRINGER INGELHEIM PHARMACEUTICALS, INC.] — DailyMed
- MedlinePlus — National Library of Medicine
- MedlinePlus Drug Information
What official patient guides say
Afatinib is one tablet by mouth once a day, taken at about the same time each day. The main daily planning point is food: take it on an empty stomach, at least 1 hour before or 2 hours after a meal or snack. Apart from that food window, you can keep your normal diet unless your doctor tells you otherwise. If you forget a dose, take it as soon as you remember — unless your next dose is due in less than 12 hours, in which case skip the missed dose and stay on your regular schedule. Never take a double dose. Keep taking afatinib even if you feel well, and tell your doctor how you are feeling, because the dose may be lowered or paused if side effects become hard to handle. In daily life, diarrhea, rash or acne-like skin changes, mouth sores, nail infections, and dry skin are common things to expect and report. Store the tablets in the container they came in, tightly closed, at room temperature and away from light, extra heat, and moisture — not in the bathroom — and out of the reach of children.
Source: MedlinePlus Drug Information
Part D formulary coverage
| Formulary summary | |
|---|---|
| Most common tier | 5 |
| Plans listing this drug | 5495 |
| Total Part D plans | 5495 |
| Share of plans listing it | 100 |
| Formularies listing it | 286 |
| Tier | Plans |
|---|---|
| Tier 1 | 123 plans |
| Tier 2 | 1 plans |
| Tier 4 | 46 plans |
| Tier 5 | 5325 plans |
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
| With Medicare Part D | |
|---|---|
| Most common tier | Tier 5 |
| Typical copay | $0 — half of plans charge between $0 and $0 |
| Typical coinsurance | 26.0% of the price |
| Based on | 5237 plans that cover this drug · 2027 plan year |
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 2026-11-07
Similar medications
Other medications in the same FDA pharmacologic class (Kinase Inhibitor):
Read next
Part D spending averages (2024)
| Brand name | Generic name | Total claims 2024 | Total spending 2024 | Total beneficiaries 2024 | Rank by beneficiaries 2024 |
|---|---|---|---|---|---|
| Gilotrif | Afatinib Dimaleate | 5410 | 6.11245e+07 | 940 | 1851 |
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
5,495 plans from 509 companies list this drug on a formulary for 2027. Search by company or plan name, or filter by tier. Cost sharing is the plan's published amount for this drug's tier in the initial coverage stage (1-month retail supply), where the plan publishes it; a blank means the plan does not publish it.
| Company | Plan | Tier | Copay | Coinsurance |
|---|
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.
Coverage and costs change. Drug lists (formularies), tiers, and copays can change during the year and differ by plan. Always check with your insurance company or plan directly to confirm what is covered and what you will pay.
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