Physician and Patient Preferences for Cell Therapies in Advanced Solid Tumors

This is a cross-sectional, questionnaire-based observational study using a discrete choice experiment (DCE) to elicit treatment preferences from oncology physicians and patients with advanced solid tumors. The study is designed and will be reported in accordance with the ISPOR good research practice guidelines for conjoint analysis. DCE attributes and levels will be developed through a structured process combining a literature review, expert consultation, and cognitive pretesting, and will span the efficacy, safety, treatment burden, and cost domains. A D-optimal fractional factorial design will be used to generate the choice tasks; each participant will be randomly assigned to a block of choice tasks, each presenting pairs of unlabeled hypothetical cell therapy profiles. Preference weights (part-worth utilities) will be estimated using random-parameters logit (mixed logit) models. Secondary analyses will examine the relative importance of attributes, maximum acceptable risk (MAR), marginal willingness to pay (mWTP) where applicable, differences in preferences between physicians and patients, and preference heterogeneity using latent class analysis and interaction-term models. Prespecified sensitivity analyses will be conducted to assess the robustness of the findings.

Inclusion criteria

• Physicians

Physicians must meet ALL of the following criteria:

• Hold a valid medical practitioner license issued in the People's Republic of China and currently practice at a medical institution in China;
• Specialize in medical oncology or another specialty directly involved in the diagnosis and treatment of solid tumors (e.g., thoracic oncology, gastrointestinal oncology, genitourinary oncology, or gynecologic oncology; surgical oncologists or radiation oncologists with prescribing authority for systemic anticancer therapy are also eligible);
• Hold a professional title of attending physician or above;
• Have directly participated in systemic treatment decision-making for patients with advanced (unresectable stage III or stage IV) solid tumors within the past 12 months;
• Have a basic understanding of cell therapies (e.g., CAR-T, TIL, TCR-T, and NK cell therapies) and their therapeutic principles;
• Participate voluntarily and provide electronic informed consent.

• Patients

Patients must meet ALL of the following criteria:

• Aged 18 years or older;
• Histologically or cytologically confirmed advanced solid tumor (unresectable stage III or stage IV; e.g., non-small cell lung cancer, hepatocellular carcinoma, colorectal cancer, gastric cancer, melanoma, or ovarian cancer);
• Received at least one prior line of systemic anticancer therapy (chemotherapy, targeted therapy, immune checkpoint inhibitors, or other cellular immunotherapy) in the advanced or metastatic setting;
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, with adequate cognitive and physical capacity to complete the questionnaire;
• Able to understand the questionnaire content independently or with assistance from a study coordinator;
• Participate voluntarily and provide electronic informed consent.

Exclusion criteria

• Physicians

Physicians meeting ANY of the following criteria will be excluded:

• Individuals engaged exclusively in basic research without direct involvement in clinical patient care;
• Individuals unable, for any reason, to understand the questionnaire content or make independent judgments.

• Patients

Patients meeting ANY of the following criteria will be excluded:

• Patients who are unaware of their tumor stage or treatment status;
• Severe cognitive impairment or psychiatric disorders that preclude comprehension of the questionnaire content or independent judgment;
• Estimated life expectancy of less than 3 months as assessed by the treating physician, or insufficient physical capacity to complete the questionnaire;
• Uncontrolled acute illness or other urgent medical conditions that make study participation inadvisable.