Last reviewed 2026-04-20 · How we verify

Symdeko (Copackaged) (TEZACAFTOR)

Tezacaftor and ivacaftor work together to increase the amount and function of CFTR protein at the cell surface, enhancing chloride transport.

Tezacaftor, marketed as part of Symdeko, is a cystic fibrosis treatment developed by Vertex Pharmaceuticals, currently generating significant revenue in the CF market. The drug's key strength lies in its mechanism of action, which enhances both the amount and function of CFTR protein, complementing ivacaftor to improve chloride transport. A primary risk is the key composition patent expiry in 2028, which could lead to increased competition from generic versions.

At a glance

Mechanism of action

Tezacaftor helps process and traffic mutant CFTR proteins to the cell surface, while ivacaftor potentiates the function of these proteins, increasing chloride transport. Together, they enhance both the quantity and function of CFTR at the cell surface.

Approved indications

• Cystic Fibrosis Treatment

Common side effects

• Headache
• Nausea
• Sinus congestion
• Dizziness

Drug interactions

• Strong CYP3A inducers (e.g., rifampin, rifabutin, phenobarbital, carbamazepine, phenytoin, St. John's wort)
• Moderate CYP3A inducers
• Strong CYP3A inhibitors (e.g., ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, clarithromycin)
• Moderate CYP3A inhibitors (e.g., fluconazole, erythromycin)
• Grapefruit juice
• Ciprofloxacin
• Sensitive CYP3A substrates (e.g., midazolam)

Key clinical trials

• Evaluation of VX-121/Tezacaftor/Deutivacaftor in Cystic Fibrosis (CF) Participants 1 Through 11 Years of Age (PHASE3)
• Evaluation of VX-828 in Healthy Participants and in Participants With Cystic Fibrosis (PHASE1)
• Effect of Vanzacaftor/Tezacaftor/Deutivacaftor (VNZ/TEZ/D-IVA) on the PK of Rosuvastatin in Healthy Participants (PHASE1)
• Evaluation of Long-term Safety and Efficacy of ELX/TEZ/IVA in Cystic Fibrosis (CF) Participants 2 Years and Older (PHASE3)
• Modulate-CF: Cystic Fibrosis Transmembrane Regulator (CFTR) Biomarker Study to Evaluate the Rescue of Mutant CFTR in Patients With Cystic Fibrosis Treated With CFTR-modulators
• Population Pharmacokinetics of Elexacaftor-tezacaftor-ivacaftor in a Paediatric Population
• Trikafta for Patients With Non-cystic Fibrosis Bronchiectasis (PHASE4)
• Evaluation of Long-Term Safety and Efficacy of Vanzacaftor/Tezacaftor/Deutivacaftor in Cystic Fibrosis Participants 1 Year of Age and Older (PHASE3)

Patents

Primary sources

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