Redefining Tolerability in Cancer Treatment
About the Research Study
Cancer treatments are more effective but increasingly complex. Yet there is no universal definition of treatment tolerability in immuno-oncology. Current measures focus on side effects and discontinuation rates, missing critical aspects of patients' daily lives.
This gap makes it harder for clinicians and patients to make informed decisions and limits regulators' ability to fully evaluate therapies.
To address this, DIA has launched the first phase of a global study to create the first standardized, patient-centered definition of treatment tolerability — one that combines clinical data with patient experience to better guide trial design, reporting, and patient care.
Tolerability isn’t just about side effects — it’s about whether patients can keep living their lives while on treatment.
Addressing Critical Gaps in Cancer Treatment
This work benefits patients, clinicians, and the life sciences community by building a shared, evidence-based understanding of what tolerability means in practice.
Bring together clinicians, patients, and researchers to agree on a rigorous, patient-centered definition of treatment tolerability in immuno-oncology.
Include treatment logistics, symptom burden, and quality of life — factors current measures miss — as core components of tolerability assessment.
Recommend trial designs, analytical methods, and PRO (patient-reported outcome) measures to assess and compare tolerability across cancer treatments.
What We Are Working to Achieve
Phase I is focused on three interconnected objectives that together establish the foundation for a globally applicable tolerability standard.
Bring together clinicians, patients, and researchers to agree on a rigorous, patient-centered definition of treatment tolerability in immuno-oncology.
Include factors like treatment logistics, symptom burden, and quality of life that current tolerability measures fail to capture in clinical trials.
Recommend trial designs, analytical methods, and PRO (patient-reported outcome) measures to assess and compare tolerability across treatments and generate real-world evidence to improve patient–clinician conversations and support shared treatment decisions.
Phase I Timeline
- Literature review and conceptual model development
- Direct input from patients and key opinion leaders (KOLs)
- Identification of relevant PRO measures or gaps needing new tools
- Analysis, reporting, and transparent dissemination of results
This phase will generate real-world evidence to improve patient–clinician conversations and support shared treatment decisions.
Identified patient experiences of treatment tolerability in oncology, focusing on lung cancer, colorectal cancer, multiple myeloma, and acute myeloid leukemia treated with immunotherapy.
Derived from the literature review, the model maps key factors influencing patients' perceptions of treatment tolerability.
Conducted interviews with patients and physicians to validate and enrich understanding of tolerability experiences.
Developed a comprehensive guide defining core tolerability concepts, integrating findings from the literature, conceptual model, and interviews to support improved clinical trial design and regulatory decision-making.
Building on Phase I insights — focused on validating key findings and developing practical recommendations for clinical trial design, analytical methods, and PRO tool implementation.
Where We Are Now
- Literature review and conceptual model development
- First round of patient and HCP input
- Finalizing interviews and analyses
- Reporting and dissemination
- Presentations at DIA 2025 Global Annual Meeting and DIA Europe 2025
- Tolerating Treatment Side Effects: Listen to the Patient Global Forum, 2026
- Immunotherapies Merit Unique Patient-Reported Outcomes to Inform Treatment Tolerability Global Forum, 2023
Founding Contributors & Sponsors
DIA is leading this initiative in collaboration with a diverse cross-sector network, including founding contributors dedicated to advancing patient-centered oncology care.
Scientific Advisors & Research Partners
A multi-stakeholder advisory network bringing together patient advocacy, academic research, and clinical expertise to guide the study.
Maria Paula Bautista Acelas serves as Senior Scientific Project Manager at DIA, where she leads day-to-day coordination and development of the Tolerability Study. She works closely with scientific advisors, research partners, and sponsor organizations to advance the study's patient-centered mission.
Dr. Vassileva has decades of experience with managing complex multi-stakeholder biomedical research programs. She spent most of her career in the nonprofit sector, leading the Science Team at the Arthritis Foundation, and working at the Foundation for NIH and the American Association for the Advancement of Science. She was also on the leadership teams of two health research organizations, serving as project director on multiple government contracts.
Her areas of expertise include musculoskeletal, metabolic, immunity and inflammation disorders, as well as patient engagement. She received her PhD in Biochemistry and Cell Biology from Johns Hopkins.
Conferences & Publications
The Tolerability Study team actively shares findings and engages the broader community through conferences and peer-reviewed publications.
Co-created with study partners to set the foundation for this initiative.
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Participation is open to DIA members and partner organizations dedicated to advancing patient-centered oncology care.
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