Open-Label, Extension Study to Evaluate the Safety of Hydrocodone Bitartrate Extended-Release Tablets

This is a 6-month, nonrandomized, open-label extension study to assess the long-term safety of hydrocodone bitartrate extended-release (ER) tablets in patients with moderate to severe chronic low back pain who require continuous opioid treatment for an extended period of time.

To be eligible for Study 3104, patients were required to have completed the entire double blind treatment period on study drug (either placebo or hydrocodone bitartrate ER tablets) through week 12 of Study 3103 (NCT01789970) and to have met the entry criteria for Study 3104.

Eligible patients from Study 3103 (NCT01789970) were enrolled for participation in this extension study. For these patients, the final study visit in Study 3103 was visit 1 for this study (also referred to as the titration or adjustment baseline visit, depending on whether the patient was enrolled under the original or amended protocol, respectively). The original protocol was amended after 26 patients had been enrolled in the study. Those who were enrolled under the original protocol participated in a double-blind titration period of up to approximately 4 weeks followed by an open-label treatment period of 22 weeks. Those patients who were enrolled under the amended protocol participated in an open-label adjustment period of up to approximately 3 weeks followed by an open-label treatment period of 22 weeks.

Eligibility Criteria:
Inclusion Criteria:

1. Patients must have participated in and completed the entire double-blind treatment period on study drug through the final study visit (week 12) of study 3103.

   NOTE: Patients who had a final on-treatment visit (i.e. prior to week 12) are not permitted to participate in study 3104.
2. The patient is able to speak English and is willing to provide written informed consent for study 3104, including re-signing a written opioid agreement, to participate in this study.
3. Women of childbearing potential (not surgically sterile or 2 years postmenopausal) must use a medically accepted method of contraception, agree to continue use of this method for the duration of the study and for 30 days after participation in the study, and have a negative pregnancy test at screening. Acceptable methods of contraception include barrier method with spermicide, intrauterine device (IUD), or steroidal contraceptive (oral, transdermal, implanted, and injected) in conjunction with a barrier method. NOTE: A woman will be considered surgically sterile if she has had a tubal ligation, hysterectomy, bilateral salpingo-oophorectomy or bilateral oophorectomy, or hysterectomy with bilateral salpingo-oophorectomy.
4. The patient must be willing and able to successfully self-administer the study drug, comply with study restrictions, and return to the study center for scheduled study visits, as specified in the protocol.
5. The patient must not participate in any other study involving an investigational agent (excluding those who participated in study 3103) while enrolled in the present study.

Exclusion Criteria:

1. The patient's current source of pain is different from the low back pain the patient was experiencing at entry into study 3103. NOTE: Any additional source of pain for a patient must be discussed with the medical monitor.
2. The patient has current evidence of alcohol or other substance abuse with the exception of nicotine or caffeine.
3. The patient has developed, during study 3103, a medical or psychiatric disease (including suicidality) that, in the opinion of the investigator, would compromise collected data.
4. The patient is expected to have surgery during the study.
5. The patient is pregnant or lactating.
6. The patient has developed an active malignancy (excluding basal cell carcinoma) during study 3103.
7. The patient has known human immunodeficiency virus (HIV).
8. In the judgment of the investigator, the patient has any clinically significant deviation from normal in the physical examination and/or clinical laboratory test values.
9. The patient has developed cardiopulmonary disease that would, in the opinion of the investigator, significantly increase the risk of treatment with opioids.
10. The patient is receiving a monoamine oxidase inhibitor (MAOI).

    * Other exclusion criteria apply.