Early Breast CancerONCO-AdherNCT06650423
Adherence to Aromatase Inhibitors ± Abemaciclib Treatment in Patients With Early-stage HER2-negative Breast Cancer
An observational study of Early Breast Cancer and Hormone Receptor Positive Tumor, run by Institute of Oncology Ljubljana at 1 site in Slovenia.
Trial summary
Around 90% of breast cancer patients are diagnosed at an early stage and approximately 70% are hormone receptor-positive and HER2-negative (HR+/HER2-). Despite advancements in adjuvant endocrine therapy, 20-30% of early-stage breast cancer patients relapse within the first decade post-surgery. Read more about this study
- Who is it for?
- Ages 18 to 99 years, women only
- Conditions the study is for
- Early Breast Cancer, Hormone Receptor Positive Tumor, HER2-negative Breast Cancer
- How many people
- 319 participants
- Where
- 1 siteSlovenia
- Study dates
- 5 Jan 2025to 1 Mar 2027
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 99 years
- Women only
- No healthy volunteers
- Adult, Older adult
Study population: Eligible adult women with early HR+ HER2- breast cancer patients.
Who may be able to join
- Female,
- Early HR+/HER-2- BC,
- Patient is receiving adjuvant therapy with an aromatase inhibitor (letrozole, anastrozole or exemestane), with or without a CDK4/6 inhibitor abemaciclib, for no more than 18 months,
- Treatment of BC is being conducted at OIL,
- Patient has mandatory health insurance through Health Insurance Institute of Slovenia,
- Patient understands Slovenian language, and
- Patient agrees to participate in the study and provides written informed consent.
Who cannot join
- Metastatic HR+/HER2-negative breast cancer
- Previous treatment for breast cancer with an aromatase inhibitor, with or without a CDK4/6 inhibitor, for early breast cancer prior to the current adjuvant treatment line
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Slovenia1 site, 1 recruiting
- Recruiting
Institute of Oncology Ljubljana
Ljubljana, 1000
Erika Matos, MD, 0038615879715, ematos@onko-i.si
Cvetka Grašič Kuhar, 015879090, cgrasic@onko-i.si
About this study
Official title: ONCO-ADHER: Adherence to Treatment With Aromatase Inhibitors With or Without Abemaciclib in Patients With Early-stage, Endocrine-dependent, HER2-negative Breast Cancer
Around 90% of breast cancer patients are diagnosed at an early stage and approximately 70% are hormone receptor-positive and HER2-negative (HR+/HER2-). Despite advancements in adjuvant endocrine therapy, 20-30% of early-stage breast cancer patients relapse within the first decade post-surgery. A recent clinically meaningful therapeutic option for these patients has been cyclin-dependent kinases 4/6 inhibitors (CDK4/6 inhibitors). Abemaciclib and ribociclib were assessed in the adjuvant setting, both showing improvement in invasive disease-free survival (IDFS). Abemaciclib has been approved by the FDA and EMA for HR+/HER2- early breast cancer at high risk of disease recurrence and is the first addition to the Slovenian treatment regimen in routine clinical practice.
Poor medication adherence can directly affect the effectiveness of treatment for early HR+/HER2- breast cancer. While adherence data in patients treated with aromatase inhibitors are available, the adherence rate in patients with early HR+/HER2- breast cancer taking abemaciclib remains unclear.
In this study, investigators hypothesize that patients receiving abemaciclib in combination with aromatase inhibitors will have lower medication adherence and higher discontinuation rates compared to those receiving aromatase inhibitors alone. It is expected that patients with better quality of life, better cognitive functioning, and a more positive attitude toward their therapy will demonstrate higher medication adherence rates. Adherence may also be influenced by additional factors, such as age and prior treatments.
Read the detailed description
Poor medication adherence can directly affect the effectiveness of treatment for early HR+/HER2- breast cancer. While data on medication adherence in patients taking aromatase inhibitors are available, the adherence rate in patients with early HR+/HER2- breast cancer taking abemaciclib remains unclear. Due to the differing characteristics of these treatment modalities, particularly their distinct safety profiles, medication adherence and persistence may vary between them.
It is hypothesized that patients receiving abemaciclib in combination with aromatase inhibitors will have lower medication adherence and higher discontinuation rates compared to those receiving aromatase inhibitors alone. It is also expected that patients with better quality of life, better cognitive functioning, and a more positive attitude toward their therapy will demonstrate higher medication adherence rates. Additionally, factors such as age and prior treatments may contribute to adherence outcomes.
- Keywords
- breast cancer, medication adherence, CDK4/6, HR+, HER2-, aromatase inhibitor, quality of life, medication belief
- Medical subject headings
- Breast Neoplasms, Medication Adherence
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Aromatase inhibitor + abemaciclib | Adult women with early HR+ HER2- breast cancer, eligible for treatment with aromatase inhibitor + abemaciclib, both prescribed prior inclusion into study, irrespective of protocol, as per regular clinical practice | |
| Aromatase inhibitor | Adult women with early HR+ HER2- breast cancer, eligible for treatment with aromatase inhibitor, prescribed prior inclusion into study, irrespective of protocol, as per regular clinical practice |
What is being measured
The primary outcome is the main question the study is designed to answer.
Medication adherence (Proportion of Days Covered, PDC) at Month 3
Medication adherence measured as Proportion of Days Covered (PDC), calculated from pill count data and expressed as percentage (%). Participants with PDC ≥80% will be classified as adherent. Self-reported adherence will additionally be assessed using the Medication Adherence Report Scale (MARS-5; score range 5-25, higher scores indicate better adherence).
Measured: Month 3 after treatment initiation
Medication adherence (Proportion of Days Covered, PDC) at Month 6
Medication adherence measured as Proportion of Days Covered (PDC), calculated from pill count data and expressed as percentage (%). Participants with PDC ≥80% will be classified as adherent. Self-reported adherence will additionally be assessed using the Medication Adherence Report Scale (MARS-5; score range 5-25, higher scores indicate better adherence).
Measured: Month 6 after treatment initiation
Secondary outcomes (13)
EORTC QLQ-C30 score at Baseline
Quality of life assessed using the EORTC QLQ-C30 questionnaire. Scores are transformed to a 0-100 scale (higher scores on functional and global scales indicate better functioning; higher scores on symptom scales indicate greater symptom burden).
Measured: Baseline visit
EORTC QLQ-C30 score at Month 3
Quality of life assessed using the EORTC QLQ-C30 questionnaire. Scores are transformed to a 0-100 scale (higher scores on functional and global scales indicate better functioning; higher scores on symptom scales indicate greater symptom burden).
Measured: Month 3
EORTC QLQ-C30 score at Month 6
Quality of life assessed using the EORTC QLQ-C30 questionnaire. Scores are transformed to a 0-100 scale (higher scores on functional and global scales indicate better functioning; higher scores on symptom scales indicate greater symptom burden).
Measured: Month 6
EORTC QLQ-BR23 score at Baseline
Quality of life assessed using the EORTC QLQ-BR23 questionnaire. Scores are transformed to a 0-100 scale (higher scores on functional scales indicate better functioning; higher scores on symptom scales indicate greater symptom burden).
Measured: Baseline visit
EORTC QLQ-BR23 score at Month 3
Quality of life assessed using the EORTC QLQ-BR23 questionnaire. Scores are transformed to a 0-100 scale (higher scores on functional scales indicate better functioning; higher scores on symptom scales indicate greater symptom burden).
Measured: Month 3
EORTC QLQ-BR23 score at Month 6
Quality of life assessed using the EORTC QLQ-BR23 questionnaire. Scores are transformed to a 0-100 scale (higher scores on functional scales indicate better functioning; higher scores on symptom scales indicate greater symptom burden).
Measured: Month 6
Beliefs about Medicines Questionnaire (BMQ) score at Baseline
Beliefs about medicines assessed using the Beliefs about Medicines Questionnaire (BMQ). Items are rated on a 5-point Likert scale and summed to generate questionnaire scores.
Measured: Baseline visit
Beliefs about Medicines Questionnaire (BMQ) score at Month 3
Beliefs about medicines assessed using the Beliefs about Medicines Questionnaire (BMQ). Items are rated on a 5-point Likert scale and summed to generate questionnaire scores.
Measured: Month 3
Beliefs about Medicines Questionnaire (BMQ) score at Month 6
Beliefs about medicines assessed using the Beliefs about Medicines Questionnaire (BMQ). Items are rated on a 5-point Likert scale and summed to generate questionnaire scores.
Measured: Month 6
FACT-Cog score at Baseline
Cognitive functioning assessed using the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) questionnaire. Items are rated on a 0-4 scale and summed to generate domain and total scores (higher scores indicate better perceived cognitive functioning).
Measured: Baseline visit
FACT-Cog score at Month 3
Cognitive functioning assessed using the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) questionnaire. Items are rated on a 0-4 scale and summed to generate domain and total scores (higher scores indicate better perceived cognitive functioning).
Measured: Month 3
FACT-Cog score at Month 6
Cognitive functioning assessed using the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) questionnaire. Items are rated on a 0-4 scale and summed to generate domain and total scores (higher scores indicate better perceived cognitive functioning).
Measured: Month 6
Adverse events during follow-up
Number of participants experiencing at least one adverse event and total number of adverse events recorded during follow-up. Adverse events will be summarized by severity and seriousness.
Measured: From treatment initiation through Month 6
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Oct 2024
- Study start5 Jan 2025
- Primary completion1 Mar 2027 (estimated)
- Study completion1 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (25)Papers the sponsor has linked to this study.
- Other trials for Early Breast CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 319 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Institute of Oncology Ljubljana
- Sponsor type
- University, hospital or other
- Collaborators
- University of Ljubljana
- Responsible party
- Sponsor
- Investigators
- Erika Matos, PhD, Principal investigator, Institute of Oncology Ljubljana, Slovenia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06650423
- Sponsor's protocol ID
- ORI2024-001
- Acronym
- ONCO-Adher
- Status last verified
- Mar 2026
- First submitted
- 16 Oct 2024
- Last updated
- 6 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Bray F, Laversanne M, Sung H, Ferlay J, Siegel RL, Soerjomataram I, Jemal A. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2024 May-Jun;74(3):229-263. doi: 10.3322/caac.21834. Epub 2024 Apr 4.
PubMed 38572751Siegel RL, Miller KD, Wagle NS, Jemal A. Cancer statistics, 2023. CA Cancer J Clin. 2023 Jan;73(1):17-48. doi: 10.3322/caac.21763.
PubMed 36633525Giaquinto AN, Sung H, Miller KD, Kramer JL, Newman LA, Minihan A, Jemal A, Siegel RL. Breast Cancer Statistics, 2022. CA Cancer J Clin. 2022 Nov;72(6):524-541. doi: 10.3322/caac.21754. Epub 2022 Oct 3.
PubMed 36190501Early Breast Cancer Trialists' Collaborative Group (EBCTCG). Aromatase inhibitors versus tamoxifen in early breast cancer: patient-level meta-analysis of the randomised trials. Lancet. 2015 Oct 3;386(10001):1341-1352. doi: 10.1016/S0140-6736(15)61074-1. Epub 2015 Jul 23.
PubMed 26211827Sheffield KM, Peachey JR, Method M, Grimes BR, Brown J, Saverno K, Sugihara T, Cui ZL, Lee KT. A real-world US study of recurrence risks using combined clinicopathological features in HR-positive, HER2-negative early breast cancer. Future Oncol. 2022 Jul;18(21):2667-2682. doi: 10.2217/fon-2022-0310. Epub 2022 May 25.
PubMed 35611679Gao JJ, Cheng J, Bloomquist E, Sanchez J, Wedam SB, Singh H, Amiri-Kordestani L, Ibrahim A, Sridhara R, Goldberg KB, Theoret MR, Kluetz PG, Blumenthal GM, Pazdur R, Beaver JA, Prowell TM. CDK4/6 inhibitor treatment for patients with hormone receptor-positive, HER2-negative, advanced or metastatic breast cancer: a US Food and Drug Administration pooled analysis. Lancet Oncol. 2020 Feb;21(2):250-260. doi: 10.1016/S1470-2045(19)30804-6. Epub 2019 Dec 16.
PubMed 31859246Johnston SRD, Harbeck N, Hegg R, Toi M, Martin M, Shao ZM, Zhang QY, Martinez Rodriguez JL, Campone M, Hamilton E, Sohn J, Guarneri V, Okada M, Boyle F, Neven P, Cortes J, Huober J, Wardley A, Tolaney SM, Cicin I, Smith IC, Frenzel M, Headley D, Wei R, San Antonio B, Hulstijn M, Cox J, O'Shaughnessy J, Rastogi P; monarchE Committee Members and Investigators. Abemaciclib Combined With Endocrine Therapy for the Adjuvant Treatment of HR+, HER2-, Node-Positive, High-Risk, Early Breast Cancer (monarchE). J Clin Oncol. 2020 Dec 1;38(34):3987-3998. doi: 10.1200/JCO.20.02514. Epub 2020 Sep 20.
PubMed 32954927Slamon D, Lipatov O, Nowecki Z, McAndrew N, Kukielka-Budny B, Stroyakovskiy D, Yardley DA, Huang CS, Fasching PA, Crown J, Bardia A, Chia S, Im SA, Ruiz-Borrego M, Loi S, Xu B, Hurvitz S, Barrios C, Untch M, Moroose R, Visco F, Afenjar K, Fresco R, Severin I, Ji Y, Ghaznawi F, Li Z, Zarate JP, Chakravartty A, Taran T, Hortobagyi G. Ribociclib plus Endocrine Therapy in Early Breast Cancer. N Engl J Med. 2024 Mar 21;390(12):1080-1091. doi: 10.1056/NEJMoa2305488.
PubMed 38507751Hershman DL, Shao T, Kushi LH, Buono D, Tsai WY, Fehrenbacher L, Kwan M, Gomez SL, Neugut AI. Early discontinuation and non-adherence to adjuvant hormonal therapy are associated with increased mortality in women with breast cancer. Breast Cancer Res Treat. 2011 Apr;126(2):529-37. doi: 10.1007/s10549-010-1132-4. Epub 2010 Aug 28.
PubMed 20803066Yussof I, Mohd Tahir NA, Hatah E, Mohamed Shah N. Factors influencing five-year adherence to adjuvant endocrine therapy in breast cancer patients: A systematic review. Breast. 2022 Apr;62:22-35. doi: 10.1016/j.breast.2022.01.012. Epub 2022 Jan 24.
PubMed 35121501Yeo HY, Liew AC, Chan SJ, Anwar M, Han CH, Marra CA. Understanding Patient Preferences Regarding the Important Determinants of Breast Cancer Treatment: A Narrative Scoping Review. Patient Prefer Adherence. 2023 Oct 31;17:2679-2706. doi: 10.2147/PPA.S432821. eCollection 2023.
PubMed 37927344Zhao M, Zhao J, Chen J, Li M, Zhang L, Luo X, Zhang Y, Xiong C, Guo Z, Yan J. The relationship between medication adherence and illness perception in breast cancer patients with adjuvant endocrine therapy: beliefs about medicines as mediators. Support Care Cancer. 2022 Dec;30(12):10009-10017. doi: 10.1007/s00520-022-07411-w. Epub 2022 Oct 20.
PubMed 36261611Agostinetto E, Vian L, Caparica R, Bruzzone M, Ceppi M, Lambertini M, Ponde N, de Azambuja E. CDK4/6 inhibitors as adjuvant treatment for hormone receptor-positive, HER2-negative early breast cancer: a systematic review and meta-analysis. ESMO Open. 2021 Apr;6(2):100091. doi: 10.1016/j.esmoop.2021.100091. Epub 2021 Mar 18.
PubMed 33743330Barroso-Sousa R, Shapiro GI, Tolaney SM. Clinical Development of the CDK4/6 Inhibitors Ribociclib and Abemaciclib in Breast Cancer. Breast Care (Basel). 2016 Jun;11(3):167-73. doi: 10.1159/000447284. Epub 2016 Jun 22.
PubMed 27493615Chan AHY, Horne R, Hankins M, Chisari C. The Medication Adherence Report Scale: A measurement tool for eliciting patients' reports of nonadherence. Br J Clin Pharmacol. 2020 Jul;86(7):1281-1288. doi: 10.1111/bcp.14193. Epub 2020 May 18.
PubMed 31823381