The purpose of this study is to check how well LY35327021 works and how safe it is for controlling nausea and vomiting caused by chemotherapy. Participants who join this study will be in it until all parts are finished, which could take about 2 months.

Inclusion Criteria:

• Chemotherapy-naive participants, planned to receive AC or cisplatin-based chemotherapy greater than or equal to (≥)70 milligrams per square meter (mg/m²), on Day 1 of each cycle, with no multiple administrations during the CINV observation period, from Day 2 to Day 5 of each cycle.
• Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.

Exclusion Criteria:

• Have symptomatic or untreated central nervous system (CNS) metastases.
• Have an established diagnosis of uncontrolled diabetes mellitus.
• Have a history of, or current evidence of, a clinically significant cardiac condition or QT/QTcF-related conditions.
• Have another etiology for nausea and vomiting, or receives medications with know or potential antiemetic activity
• Signs, symptoms or history of thyroid tumors
• Receives treatment with a gastric inhibitory polypetide (GIP) or glucagon-like peptide-1 (GLP-1) receptor agonist within 4 weeks prior to chemotherapy.
• Have participated in a clinical study involving study intervention within 30 days of Cycle 1 Day 1 (C1D1). If the previous study intervention has a long half-life, within 3 months or 5 halflives, whichever is longer, of C1D1.
• Are pregnant, breastfeeding, or intend to become pregnant during the study or within 30 days of the last dose of study intervention.

Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.

Data are available 6 months after the primary publication and approval of the indication studied in the US and EU, whichever is later. Data will be indefinitely available for requesting.

A research proposal should be approved by an independent review panel and researchers should sign a data sharing agreement.