A Trial of TAK-788 (AP32788) in Non-small Cell Lung Cancer (NSCLC)

This phase 1/2 study will evaluate the safety, pharmacokinetics, and anti-tumor activity of
oral EGFR/HER2 Inhibitor TAK-788 in participants with NSCLC and anti-tumor activity of
TAK-788 in participants with solid tumors other than NSCLC with EGFR or HER2 mutations. The
trial will be conducted in three parts: a dose escalation and expansion phase, followed by an
extension phase.

The objectives of the dose escalation phase are to determine the safety profile of orally
administered TAK-788, including the MTD, DLTs, RP2D and pharmacokinetic profile. The primary
goal of the expansion component of the trial is to evaluate the anti-tumor activity of
TAK-788 in seven histologically and molecularly defined cohorts at the RP2D (determined based
on dose escalation phase of the trial).

The seven expansion cohorts will be:

1. NSCLC participants with EGFR exon 20 activating insertions, who have either not received
or not shown an objective response to an EGFR TKI, and who have no active, measurable
CNS metastases;

2. NSCLC participants with HER2 exon 20 activating insertions or point mutations and no
active, measurable CNS metastases;

3. NSCLC participants with EGFR exon 20 activating insertions or HER2 exon 20 activating
insertions or point mutations and active, measurable CNS metastases;

4. NSCLC participants with other targets against which TAK-788 is active (examples include
EGFR exon 19 deletions or exon 21 substitutions [with or without T790M mutations] and
other uncommon EGFR activating mutations), with or without active, measurable CNS
metastases;

5. NSCLC participants with EGFR exon 20 activating insertions, who have previously shown an
objective response to an EGFR TKI and subsequently progressed, with or without active,
measurable CNS metastases;

6. NSCLC participants with EGFR exon 20 activating insertions, who have not received prior
systemic anticancer treatment for locally advanced or metastatic disease, with or
without active, measurable CNS metastases; and

7. Participants with solid tumors other than NSCLC with EGFR/HER2 mutations against which
TAK-788 is active, with or without active, measurable CNS metastases.

The extension phase will evaluate efficacy of TAK-788 in participants with locally advanced
or metastatic NSCLC whose tumors harbor EGFR exon 20 insertion mutations and who have been
previously treated. The study will enroll approximately 341 participants.

General Inclusion Criteria (all cohorts: dose escalation and expansion):

1. Have histologically or cytologically confirmed locally advanced (and not a candidate
for definitive therapy) or metastatic NSCLC (Stage IIIB or IV) or other solid tumors.
For all cohorts except Expansion Cohort 7, the locally advanced or metastatic disease
is NSCLC. For Expansion Cohort 7, the locally advanced or metastatic disease is any
solid tumor other than NSCLC

2. Must have sufficient tumor tissue available for analysis.

3. Must have measurable disease by response evaluation criteria in solid tumors (RECIST)
v1.1.

4. Male or female participants greater than or equal to (>=) 18 years old. For
participants in Japan, aged >=20 years.

5. Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1.

6. Minimum life expectancy of 3 months or more.

7. Adequate organ function at baseline.

8. Normal QT interval on screening electrocardiogram (ECG), defined as QT interval
corrected (Fridericia) (QTcF) of less than or equal to (<=) 450 millisecond (ms) in
males or <=470 ms in females.

9. Willingness and ability to comply with scheduled visits and study procedures.

Part 1: Dose Escalation Cohort Specific Inclusion Criteria:

1. Refractory to standard available therapies.

Part 2: Expansion Cohort 1 Specific Inclusion Criteria:

1. Have a documented EGFR in-frame exon 20 insertion by a local test.

2. Previously treated with one or more regimens of systemic therapy for locally advanced
or metastatic disease.

3. Prior treatment with an EGFR TKI is allowed unless the participants had an objective
response and subsequent progression as assessed by the investigator or treating
physician.

Expansion Cohort 2 Specific Inclusion Criteria:

1. Have one of the following documented by a local test:

1. A HER2 exon 20 insertion;

2. An activating point mutation in HER2.

2. Previously treated with one or more regimens of systemic therapy for locally advanced
or metastatic disease.

3. Prior treatment with a pan-HER TKI (example, afatinib, neratinib, or dacomitinib) is
allowed unless the participants had an objective response and subsequent progression
as assessed by the investigator or treating physician.

Part 2: Expansion Cohort 3 Specific Inclusion Criteria:

1. Have one of the following documented by a local test:

1. An EGFR exon 20 insertion;

2. A HER2 exon 20 insertion;

3. An activating point mutation in HER2.

2. Previously treated with one or more regimen of systemic therapy for locally advanced
or metastatic disease.

3. For participants with an EGFR exon 20 insertion: prior treatment with an EGFR TKI is
allowed unless the participants had an objective response and subsequent progression
as assessed by the investigator or treating physician during treatment with that prior
TKI.

4. For participants with a HER2 exon 20 insertion or HER2 activating point mutation:
prior treatment with a pan-HER TKI (example, afatinib, neratinib, or dacomitinib) is
allowed unless the participants had an objective response and subsequent progression
as assessed by the investigator or treating physician during treatment with that prior
TKI.

5. Have either previously untreated intracranial CNS metastases or previously treated
intracranial CNS metastases with radiologically documented new or progressing CNS
lesions.

6. Have at least one target (that is, measurable) intracranial CNS lesion (>=10
millimeter [mm] in longest diameter by contrast enhanced magnetic resonance imaging
[MRI]).

Part 2: Expansion Cohort 4 Specific Inclusion Criteria:

1. Have one of the following documented by a local test: an activating mutation in EGFR
including exon 19 deletions or exon 21 L858R substitution (with or without T790M), or
an uncommon activating mutation other than exon 20 insertion including, but not
limited to, G719X (where X is any other amino acid), S768I, L861Q, or L861R.

2. Treatment naive for locally advanced or metastatic disease or previously treated with
one or more regimens of systemic therapy for locally advanced or metastatic disease.

3. Have or do not have active (untreated or progressing) CNS metastases.

Part 2: Expansion Cohort 5 Specific Inclusion Criteria:

NSCLC participants with EGFR exon 20 activating insertions, who have previously shown an
objective response to an EGFR TKI and subsequently progressed, with or without active,
measurable CNS metastases.

1. Have a documented EGFR in-frame exon 20 insertion by a local test.

2. Previously treated with one or more regimens of systemic therapy for locally advanced
or metastatic disease.

3. Previously showed an objective response to an EGFR TKI and subsequently progressed as
assessed by the investigator or treating physician.

4. Have or do not have active (untreated or progressing) CNS metastases.

Part 2: Expansion Cohort 6 Specific Inclusion Criteria:

NSCLC participants with EGFR exon 20 activating insertions, who have not received prior
systemic anticancer treatment for locally advanced or metastatic disease, with or without
active, measurable CNS metastases.

1. Have a documented EGFR in-frame exon 20 insertion by a local test.

2. No prior systemic treatment for locally advanced or metastatic disease.

3. Have or do not have active (untreated or progressing) CNS metastases.

Part 2: Expansion Cohort 7 Specific Inclusion Criteria:

Participants with solid tumors other than NSCLC with EGFR/HER2 mutations against which
TAK-788 is active, with or without active, measurable CNS metastases.

1. Have a solid tumor that is not NSCLC and that is refractory to standard therapy.

2. Have EGFR or HER2 mutations, documented by a local test.

3. Have or do not have active (untreated or progressing) CNS metastases.

Part 3: Extension Cohort Specific Inclusion Criteria:

1. Have a documented EGFR in-frame exon 20 insertion by a local test and sufficient tumor
tissue available for central analysis.

2. Brain metastases are allowed if they have been treated with surgery and/or radiation
and have been stable without requiring corticosteroids to control symptoms within 7
days prior to the first dose of TAK-788.

3. Must have received at least 1 prior line of therapy for locally advanced or metastatic
disease and no more than 2 regimens of systemic anticancer chemotherapies for locally
advanced or metastatic disease.

- Prior treatment with an EGFR TKI is allowed unless the participant had an
objective response and subsequent progression as assessed by the investigator or
treating physician during treatment with that prior TKI.

Exclusion Criteria:

1. Previously received TAK-788.

2. Received small-molecule anticancer therapy (including cytotoxic chemotherapy, and
investigational agents, <=14 days prior to first dose of TAK-788 (except for
reversible EGFR TKIs [that is, erlotinib or gefitinib], which are allowed in the dose
escalation and expansion cohorts up to 7 days prior to the first dose of TAK-788).

3. Received antineoplastic monoclonal antibodies including immunotherapy within 28 days
of the first dose of TAK-788.

4. Have been diagnosed with another primary malignancy other than NSCLC except for
adequately treated non-melanoma skin cancer or cervical cancer in situ; definitively
treated non-metastatic prostate cancer; or participants with another primary
malignancy who are definitively relapse-free with at least 3 years elapsed since the
diagnosis of the other primary malignancy.

Note: This exclusion criteria does not apply to Expansion Cohort 7.

5. Received radiotherapy <=14 days prior to the first dose of TAK-788. SRS and
stereotactic body radiosurgery are allowed up to 7 days prior to the first dose.

6. Received a strong CYP4503A inhibitor or strong CYP3A inducer within 2 weeks prior to
first dose of TAK-788.

7. Have undergone major surgery within 28 days prior to first dose of TAK-788. Minor
surgical procedures, such as catheter placement or minimally invasive biopsy, are
allowed.

8. Have symptomatic CNS metastases (parenchymal or leptomeningeal) at screening or
asymptomatic disease requiring corticosteroids to control symptoms within 7 days prior
to the first dose of TAK-788.

9. Have current spinal cord compression (symptomatic or asymptomatic and detected by
radiographic imaging) or leptomeningeal disease (symptomatic or asymptomatic).

10. Have significant, uncontrolled, or active cardiovascular disease.

11. Have a known history of uncontrolled hypertension. Participants with hypertension
should be under treatment on study entry to control blood pressure.

12. Have prolonged QTcF interval, or being treated with medications known to be associated
with the development of Torsades de Pointes.

13. Have an ongoing or active infection, including but not limited to, the requirement for
intravenous (IV) antibiotics, or a known history of human immunodeficiency virus
(HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV). Testing is not required in
the absence of history.

14. Currently have or have a history of interstitial lung disease, radiation pneumonitis
that required steroid treatment, or drug-related pneumonitis.

15. Female participants who are lactating and breastfeeding or have a positive urine or
serum pregnancy test during the screening period.

Note: Female participants who are lactating will be eligible if they discontinue
breastfeeding.

16. Have gastrointestinal illness or disorder that could affect oral absorption of
TAK-788.

17. Have any condition or illness that, in the opinion of the investigator, might
compromise participant safety or interfere with the evaluation of the safety of the
drug.