Based on PK data, product did not meet requirement for further development.

The purpose of this study is to evaluate the safety of the matrix fentanyl patch ZR-02-01 in providing relief of cancer pain.

This study will evaluate the safety of the matrix fentanyl patch. The study will be conducted in opioid-tolerant patients with moderate to severe cancer pain currently taking an around-the-clock opioid. Patients will discontinue their current opioid regimen and begin using ZR-02-01 as soon as possible under the direction of the physician investigator upon entry into the study. Patient's dose of ZR-02-01 will be determined by the investigator using sponsor-provided conversion. Pain therapy will be under the supervision of the physician investigator.

Inclusion Criteria:

• Patient is at least 18 and no older than 75 years of age at the time of screening
• Patient has a diagnosis of cancer
• Patient has moderate to severe pain that is related to cancer or its treatment and is expected to last indefinitely and is currently taking an around-the-clock opioid to treat his/her pain
• Patient is already receiving opioid therapy, has demonstrated opioid tolerance
• A responsible adult caregiver is available in the event of an emergency at home

Exclusion Criteria:

• Patient has uncontrolled or rapidly escalating pain as determined by the investigator
• Patient has a history of substance abuse or has a substance abuse disorder