<p>This research explores the growing importance of qualitative in-trial research (ITR) in regulatory and health technology assessment (HTA) decision making. Since 2020, the Food and Drug Administration (FDA) and European Medicines Agency (EMA) have emphasized incorporating patient experience data into drug development and approval. We reviewed regulatory guidance documents, drug approval records, and HTA reports from January 2017 to March 2025. This included labels and reviews for new drug applications from the FDA and EMA, the Patient-Focused Drug Development guidance series, guidance on rare diseases, oncology, and gene therapy, and methodological guidance from HTA bodies in Scotland, the UK, France, Germany, Italy, and Spain. From more than 1000 drug applications assessed by both regulatory agencies, only ten and eight products (from the FDA and EMA, respectively) included ITR, with 55% of these for rare diseases. Both agencies used ITR data to gain insights into symptoms and patient experiences, the relevance of patient-reported outcome concepts, and meaningful changes in symptoms or treatment benefits; and to support the interpretation of meaningful score or endpoint changes. Two products included ITR data in both FDA and EMA reviews/labels. Three HTA bodies published guidance documents on qualitative research, with only two products out of eight reviewed including qualitative data in HTA reports.</p><p>Despite increasing use, ITR in regulatory submissions and HTA reviews remains limited. Early planning and alignment of ITR objectives with regulatory and HTA requirements are needed to enhance the relevance and impact of qualitative evidence in drug development and healthcare decision making.</p>