Pirfenidone is an oral anti-scarring medicine, approved only for a progressive lung disease, now explored to make cancers more treatable by softening the scar-like tissue that shields tumors. Laboratory and animal studies are supportive, and people with lung scarring show early signs of lower cancer risk. No completed human trial confirms longer survival; it remains investigational and genuinely uncertain. (Full Review)

Protocol

Dose

801 mg 3× daily

Three 267 mg capsules with food; 2,403 mg/day total

Titration

2-week ramp-up

Start at one capsule 3× daily, increase to full dose over ~two weeks

Schedule

Split, 3× daily with meals

Short half-life (~2.5–3 h) requires split dosing to hold levels

Time to effect

Biological effect

Gradual over weeks

Effects on inflammation and scarring build slowly; no rapid, felt effect

Full dose

~2 weeks

Time to reach the full 2,403 mg/day dose via titration

Response check

Every 6–12 weeks

Tumor response reassessed by imaging, per accompanying therapy

Benefits

Medium: Reduced perioperative risk in lung cancer surgery

Low: Lower lung cancer incidence; stromal normalization and improved drug delivery; chemosensitization through fibroblast targeting

Speculative: Suppression of metastasis; enhanced immunotherapy response; radiosensitization

Contraindications

Strong CYP1A2 inhibitors (fluvoxamine)

Severe liver impairment (Child-Pugh C)

Severe renal impairment (creatinine clearance <30 mL/min)

Pregnancy or breastfeeding

Key Interactions

Moderate CYP1A2 inhibitors (ciprofloxacin, fluoroquinolones)

CYP1A2 inducers (rifampicin, omeprazole, tobacco smoke)

Over-the-counter proton-pump inhibitors, antacids (omeprazole)

Grapefruit juice

Hepatotoxic or enzyme-modifying supplements (St. John's Wort, green tea extract, kava)

Photosensitizers, CYP1A2 substrates (caffeine, melatonin)

Concurrent chemotherapy, radiotherapy, immunotherapy

Risk & Side Effects

High: Gastrointestinal effects; photosensitivity and skin rash; elevated liver enzymes

Medium: Fatigue, dizziness, and headache; anorexia and weight loss

Low: Serious drug-induced liver injury; angioedema and severe hypersensitivity

Speculative: Additive toxicity in anticancer combinations; photosensitivity-related skin cancer risk

Monitoring

Marker	Target	Why
ALT	<25 U/L (men), <20 U/L (women)	Detects drug-induced liver-cell stress early
AST	<25 U/L	Complements ALT in tracking liver injury
Total bilirubin	0.3–1.2 mg/dL	Rise with enzyme elevation signals significant liver injury
GGT	<20 U/L	Adds specificity for liver/biliary stress
eGFR	>90 mL/min/1.73m²	Confirms kidneys can clear the drug's metabolite

Cadence: Baseline, then liver enzymes monthly for the first 6 months, then every 3 months; kidney function and weight at each visit; tumor imaging every 6–12 weeks

Qualitative Assessment

Energy and fatigue levels day to day
Gastrointestinal tolerance (nausea, appetite, bowel habits)
Skin sensitivity to sunlight and any rash
Appetite and body weight stability
Cancer-related symptoms and overall functional status

Pirfenidone to Treat Cancer

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment