Observational Study of Efficacy, Safety and Tolerability of Fentanyl in Korean Cancer Patients

The purpose of this observational study is: To observe the efficacy, safety, and tolerability of Abstral ODT for the alleviation of breakthrough cancer pain in Korean patients with various cancers in real-world clinical settings and supplement and expand the previous cross-sectional survey results.

This is a multicenter, non-interventional, single-arm, non-randomized observational study designed to collect the efficacy, safety, and tolerability data of Abstral ODT for the treatment of breakthrough cancer pain in cancer patients in real-world outpatient and inpatient clinical settings. As the purpose of this study is to investigate the efficacy and safety of Abstral ODT in routine clinical practice, drug prescription and treatment will be determined according to the medical judgment of the investigator, regardless of enrollment to this study. During the patient's visit to the institution, Abstral ODT will be prescribed according to the judgment of the investigator, and study participation will be suggested for this patient. Whether to participate in this study or not will not affect the patient's treatment (physician's prescription or diagnostic and therapeutic decision). Due to the non-interventional observational nature of this study, there will be no visits or procedures to be performed mandatorily according to the protocol, and data will be collected at Week 1 (±3 days), Week 4 (±1 week), and Week 12 (±4 weeks) from the baseline visit according to the circumstances of clinical practice. Status of successful dose titration for Abstral ODT will be determined according to the criteria in which dose titration is deemed successful when all of the following are met, and ineffective when one of the following is not met: no additional dose is administered within 2 h of administration of Abstral ODT during maintenance phase; Numeric Rating Scale scores at 30 and 60 min after administration is reduced by ≥2; adverse drug reactions are tolerable for the subject.The overall procedures of this study are as follows.