A Study for Subjects Who Are Participating in an Astellas-sponsored ASP8273 Study

This is a multicenter, rollover study for subjects with non-small cell lung cancer (NSCLC)
with an epidermal growth factor receptor (EGFR) activating mutation who are currently
participating in studies evaluating ASP8273.

Subjects should sign the informed consent at cycle 1 day 1 visit. The assessments from the
last treatment visit from the parent study can be utilized for the cycle 1 day 1 visit.
Either local or central laboratories may be utilized for the cycle 1 day 1 visit if
assessments are used from the last treatment visit of the parent study. The subject will
then receive ASP8273 study drug for the rollover study and return all ASP8273 study drug
from the parent study. Subjects will continue on to subsequent 28-day cycles until 1 of the
discontinuation criteria are met. Upon enrollment, subjects with fewer than 6 cycles of
study drug dosing in the parent study will return to the clinic on day 1 of each cycle up to
cycle 5. After cycle 5, these subjects can switch to day 1 of every other odd cycle for
clinic visits. Subjects with 6 or more cycles of study drug dosing upon enrollment into the
rollover study will return to the clinic on day 1 of every other odd cycle (e.g., cycles 3,
5, etc.). Imaging methods and frequency will be performed per standard of care.

An end of treatment study visit will be conducted 30 days after the last dose of study
medication.

Inclusion Criteria:

- Subject must be participating in an Astellas-sponsored ASP8273 study which has
completed, at a minimum, the primary analysis or have completed the individual study
evaluation period requirements. Subject must not have met any discontinuation
criteria in the parent study.

- Subject must be receiving a stable dose of ASP8273 for 14 days minimum and is able to
enroll into this rollover study without treatment interruption of study drug, or with
no more than 21 consecutive days of treatment interruption in study drug within the
parent study.

- Subject should be deriving clinical benefit without any persistent intolerable
toxicity from continued treatment of ASP8273.

- Subject agrees not to participate in another interventional study while on treatment.

Exclusion Criteria:

- Subject who developed persistent intolerable toxicity to ASP8273 treatment in the
parent study.

- Subject who received any other systemic anticancer treatment after parent study entry
(radiation to local areas such as bone or brain if received in the parent ASP8273
study is permitted).

- Subject who requires the following medications will be excluded:

- Chemotherapy, radiotherapy, immunotherapy or other medications intended for
antitumor activity

- Investigational products or therapy other than ASP8273

- Strong inhibitors or inducers of CYP3A4

- Permeability-glycoprotein (P-gp) substrates with a narrow therapeutic index

- Subject has any condition which may require treatment during the study and may make
the subject unsuitable for study participation.