A Study of Abemaciclib (LY2835219) in Participants With Non-Small Cell Lung Cancer or Breast Cancer

Inclusion Criteria:

- Have a Stage IV diagnosis of 1 of the following: Part A: NSCLC (Kirsten rat sarcoma
mutant [KRAS mt], PD-L1+); Part B: NSCLC (squamous histology); Part C: metastatic
breast cancer (HR+, HER2-); or Part D: locally advanced or metastatic breast cancer
(HR+, HER2-)

- Part A: must be chemotherapy naïve for metastatic NSCLC

- Part B: must have received at least 1 prior therapy containing platinum-based
chemotherapy for advanced/metastatic NSCLC

- Part C: must have previously received prior treatment with at least 1 but no more
than 2 chemotherapy regimens in the metastatic setting

- Part D: cannot have received endocrine therapy or chemotherapy as treatment in
the locoregionally recurrent or metastatic breast cancer disease setting. Note:
Participants may be enrolled if they received prior (neo)adjuvant chemotherapy or
endocrine therapy for localized disease.

- Are amenable to provide tumor tissue prior to treatment and provide tumor tissue after
treatment initiation (both mandatory).

- Have presence of measurable disease as defined by Response Evaluation Criteria in
Solid Tumors (RECIST 1.1).

- Have a performance status (PS) ≤1 on the Eastern Cooperative Oncology Group (ECOG)
scale.

- Have discontinued all previous treatments for cancer and recovered from the acute
effects of therapy.

- Have an estimated life expectancy of ≥12 weeks.

- For Part D: Have postmenopausal status due to surgical/natural menopause or chemical
ovarian suppression (initiated 28 days prior to Day 1 of Cycle 1) with a
gonadotropin-releasing hormone (GnRH) agonist such as goserelin or radiation-induced
ovarian suppression.

Exclusion Criteria:

- Have a personal history of any of the following conditions: syncope of either
unexplained or cardiovascular etiology, ventricular arrhythmia (including but not
limited to ventricular tachycardia and ventricular fibrillation), or sudden cardiac
arrest. Exception: subjects with controlled atrial fibrillation for >30 days prior to
study treatment are eligible.

- Have central nervous system (CNS) metastasis with development of associated
neurological changes 14 days prior to receiving study drug.

- Have corrected QT interval of >470 milliseconds on screening electrocardiogram (ECG).

- Have history of interstitial lung disease or pneumonitis.

- Have history of or active autoimmune disease, or other syndrome that requires systemic
steroids or autoimmune agents for the past 2 years.

- Have received a live vaccination within 30 days of study start.

- Have received prior treatment with an anti PD-1, anti-programmed death ligand 1
(PD-L1), or anti cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) agent.

- For Part D Only:

- Have initiated bisphosphonates or approved RANK ligand (RANK-L) targeted agents
(for example, denosumab) <7 days prior to Cycle 1 Day 1.

- Are currently receiving or have previously received endocrine therapy for
locoregionally recurrent or metastatic breast cancer. Note: A participant may be
enrolled if she received prior (neo)adjuvant endocrine therapy (including, but
not limited to anti-estrogens or aromatase inhibitors) for localized disease.

- Are currently receiving or have previously received chemotherapy for
locoregionally recurrent or metastatic breast cancer. Note: Participants may be
enrolled if they received prior (neo)adjuvant chemotherapy for localized disease.