Study to Assess the Effect of Osimertinib (TAGRISSO™ ) on Blood Levels of Fexofenadine in Patients With EGFRm+ NSCLC

This is a Phase I, open-label, non-randomised, two-part study in patients with EGFRm+ NSCLC who have progressed on an EGFR-TKI. The PK phase will assess the effect of osimertinib on the PK parameters of fexofenadine following both single and multiple oral dosing of osimertinib. Continued access will provide patients with further access to osimertinib after the PK phase. The study will be conducted at approximately 10 sites across Asia and Western Europe, with approximately 24 patients enrolled in order to achieve at least 18 evaluable patients. Additional patients may be dosed to ensure the minimum number of evaluable patients. PK phase The PK phase is a non-randomised, open-label, 2-period design. Treatment Period 1 and Treatment Period 2 are separated by a 3 to 7 day washout period between doses. A study flow chart for the PK phase is presented in Figure 1. Patients will receive osimertinib 80 mg as a single dose on Day 1 of Treatment Period 2, then 80 mg once daily for 38 days (from Day 4 to Day 41 in Treatment Period 2). Patients will also receive a single oral dose of fexofenadine on Day 1 in Treatment Period 1, and on Days 1 and 39 in Treatment Period 2. Continued access On completion of the PK phase (ie, following collection of the 72-hour fexofenadine sample on Day 42), patients may continue to take osimertinib tablets (80 mg once daily) as a single agent in continued access if they and the Investigator agree that this is appropriate. This will continue until the Investigator believes they are no longer deriving clinical benefit, or they stop taking osimertinib for any other reason. No clinical data will be collected during this phase other than sudden death of unknown reason, serious adverse events (SAEs) that may be related to osimertinib, outcomes of pregnancy and drug dispensing/accountability. If a patient discontinues treatment during the PK phase, they will return to the clinic for follow-up assessments 30 days (±7 days) after their last dose of treatment in the PK phase. If the patient's last dose of osimertinib is in continued access, the patient should be contacted 30 days after their last dose of osimertinib to follow-up any existing SAEs, monitor for new SAEs that may be related to the IP, and record any sudden deaths of unknown cause.