The present study aims to investigate a proactive strategy including Salovum™ and SPC-flakes to prevent the occurrence of abemaciclib-induced diarrhea in patients with early breast cancer.

In patients with high-risk luminal breast cancer, the addition of CDK 4/6-inhibitor abemaciclib to adjuvant endocrine therapy for two years has been associated with improved disease-free survival and is now recommended from national and international guidelines as the preferred treatment strategy for this patient group. However, patients treated with abemaciclib have higher risk of diarrhea which primarily occurs during the first three months from treatment initiation and seems to impact patients' quality of life. As a result, early and proactive strategies to reduce the occurrence of diarrhea from the initiation of abemaciclib should be investigated to ensure that patients in whom adjuvant abemaciclib is recommended can complete their treatment as planned.

Inclusion Criteria:

• Age ≥ 18 years.
• Histologically confirmed diagnosis of luminal breast cancer.
• No clinical evidence of metastatic disease.
• Planned to start abemaciclib in adjuvant setting (according to current national guidelines).
• Signed informed consent.

Exclusion Criteria:

• Contraindications to the investigational product, e g known or suspected hypersensitivity to the investigational products or expected inability to their use in accordance with the protocol.
• Lack of suitability for participation in the study, e g expected difficulties to follow the protocol procedures, as judged by the investigator.
• Prior exposure to abemaciclib.
• Prior exposure to Salovum or SPC-flakes.
• Past or present history of inflammatory bowel disease.

double-blind, placebo controlled