Primary Objective:

To determine the feasible dose range of Painkyl® required for Taiwanese population.

Secondary Objectives:

To evaluate the efficacy of Painkyl® by calculating squared mean of pain intensity difference at 30 minutes after taking Painkyl® (SPID30, an 11-point scale).

To evaluate subjects' satisfaction by conducting global evaluation of medication performance (a 5-point categorical scale).

To identify percentage of episodes requiring rescue medication during maintenance treatment period.

To evaluate the safety data of Painkyl® for breakthrough pain.

The primary endpoint was the feasible range of FBSF required for Taiwanese population. The secondary endpoints were the difference in pain intensity at 30 minutes (PID30) after FBSF administration, subjects' satisfaction, and the percentage of episodes requiring rescue medications.

Pain intensity was determined using an 11-point numeric scale from 0="no pain" to 10="worst pain." Patients were assessed with baseline pain as well as pain intensity at 30 minutes after dosing. The PID30 was obtained by baseline pain score minus score rated 30 minutes after dosing.

Patient's satisfaction was assessed using a 5-point (poor, fair, good, very good, and excellent) categorical scale at 30 minutes after taking FBSF with the following question: "What was your overall satisfaction with the medication?" At each episode of BTP, subjects recorded whether a rescue medication was taken after administration of FBSF.

Inclusion Criteria:

• a. a stable current regimen of oral opioids equivalent to 60-1000 mg/day of oral morphine or 20-120 mg/day of iv morphine or 25-300 mcg/hr of transdermal fentanyl for one week or longer;
• b. regularly experienced 1 to 3 breakthrough pain episodes per day that required additional opioids from pain control;
• c. at least partial relief of breakthrough pain by use of opioid therapy;
• d. 20 years of age or older;
• e. ability to understand and willingness to sign a written informed consent document;
• f. able to self-administer the study medication correctly or has the availability of a responsible adult caregiver available to administer the study medication correctly;
• g. willing and able to complete patient diary with each pain episode

Exclusion Criteria:

• a. rapidly escalating pain (e.g., regularly more than 3 breakthrough pain episodes per day) that are hard to be controlled by analgesics;
• b. history of hypersensitivity or intolerance to fentanyl;
• c. cardiopulmonary disease that, in the opinion of the investigator, would significantly increase the risk of respiratory depression;
• d. psychiatric/cognitive or neurological impairment that would limit the subject's ability to understand or complete the diary;
• e. moderate (Grade 3) to severe (Grade 4) mucositis (subjects with less than moderate mucositis are permitted and must be instructed to not apply the Painkyl® film at a site of inflammation);
• f. abnormal oral mucosa which will impede drug absorption;
• g. currently under other treatments that may alter effect of pain control based on investigator's judgment;
• h. recent history or current evidence of alcohol or other drug substance (licit or illicit) abuse;
• i. use of an investigational drug within 4 weeks preceding this study;
• j. pregnant women or nursing mothers, or positive pregnancy test for women of childbearing potential;