Human chromaffin cell graft into the CSF for cancer pain management: a prospective phase II clinical study

A number of pre-clinical studies have demonstrated the value of adrenal med ullary allografts in the management of chronic pain. The present longitudin al survey studied 15 patients transplanted for intractable cancer pain afte r failure of systemic opioids due to the persistence of undesirable side-ef fects. Before inclusion, all the patients had their pain controlled by dail y intrathecal (I-Th) morphine administration. The main evaluation criteria of analgesic activity of the chromaffin cell allograft was the complementar y requirement of analgesics and in particular the consumption of I-Th morph ine required to maintain effective pain control. Out of the 12 patients who profited from enhanced analgesia with long-term follow-up (average 4.5 mon ths), five no longer required the I-Th morphine (with prolonged interruptio n of systemic opioids as well), two durably decreased I-Th morphine intake and five were stabilized until the end of their follow-up. Durable decline and stabilization were interpreted as indicative of analgesic activity by c omparison with the usual dose escalation observed during disease progressio n. In most,cases, we noted a relationship between analgesic responses and C SF met-enkephalin levels. The results of this phase II open study demonstra te the feasibility and the safety of this approach using chromaffin cell gr afts for long-term relief of intractable cancer pain. However, while analge sic efficacy was indicated by the reduction or stabilization in complementa ry opioid intake, these observations will need to be confirmed in a control led trial in a larger series of patients. (C) 2000 International Associatio n for the Study of Pain. Published by Elsevier Science B.V. All rights rese rved.