Real-Life Data on Ziconotide-Based Intrathecal Therapy in Patients With Cancer Pain: Interim Analysis of the...

This study aimed to provide real-world data on the utilization of ziconotide-containing intrathecal (IT) treatment.

This ongoing European multicenter, prospective observational study included patients experiencing severe refractory chronic pain, eligible for IT analgesia using ziconotide. Patients are treated and observed according to the site's usual practice. The study includes an interim analysis of the French cohort of patients with cancer pain.

The study analyzed 211 patients, with a median age of 61.7 years and a median baseline numerical rating scale (NRS) pain score of 5 (0‒10), with a neuropathic component in 39%. At IT treatment initiation, approximately 50% of participants received antidepressants and 45% antiepileptics; the median dose of oral opioids was 300 oral morphine equivalents (OME) (4.5‒2400). Mean and median initial doses of ziconotide were 0.4 and 0.5 μg/d, respectively, administered in combination with morphine and local anesthetics. Dose increased over time but remained low (median: 1.6 μg/d at three months). A reduction in pain was observed in most patients, particularly in those with pain scores ≥5 (n = 90, 18% with NRS score of 0 and 14.4% with score of 1 or 2 at one month). After three months, pain scores remained globally stable; the median OME reduction was 89.7%. Most adverse events (AEs) (62%) were reported within the first month, primarily graded 1 or 2. The most frequently reported AEs were drowsiness (51% of patients), confusion (46%), hallucinations (40%), nausea (37%), memory disorders (29%), asthenia (22%), dizziness (21%), constipation (17%), diarrhea (17%), and vomiting (12%). AEs resolved completely in 70.1% of patients, partially in 10%, remained stable in 12.3%, and worsened in 1.9% (issue not known in 16.6%).

IT therapy combining ziconotide with morphine and a local anesthetic is an effective option for managing cancer-related pain in patients who have inadequate response to, or poor tolerance of, conventional systemic analgesics.

The Clinicaltrials.gov registration number for the study is NCT04321408.