June 29, 2006
Comments (0)
Implantable Device May Offer Better Pain Management
National Cancer Institute
Patients with advanced cancer who used an implantable drug-delivery device to control their pain had better pain relief, fewer toxic side effects, and better survival than patients who received intensive medical pain management, researchers reported in the October 1, 2002, issue of the Journal of Clinical Oncology.
The multicenter trial involved 202 patients who were randomly assigned to two groups. One group received comprehensive medical management (CMM) for their pain. CMM is a more systematic approach to pain control than cancer patients typically receive. It involves a team of health care professionals with special training in pain management who search for the most effective pain medication for each patient by starting with the least toxic and only gradually moving up to medications with more side effects until the pain is relieved. CMM may also include the use of complementary methods of pain reduction such as relaxation, guided imagery, psychotherapy, and patient support groups.
The trial's second group received CMM plus the implantable device. Implantable drug delivery systems (IDDSs) deliver narcotic pain medications directly to the spinal fluid, using much smaller doses than are required when the same drugs are taken by mouth or injected. The device consists of a small, battery-powered, programmable pump implanted under the skin of the abdomen and connected to a small catheter. Although IDDSs have been in use since 1991, this was the first randomized trial to compare the device with CMM for cancer pain.
Upon entering the study, most trial participants were taking at least 250 milligrams per day of narcotic pain relievers, such as morphine. Many were also taking additional medications such as antidepressants and anticonvulsants for pain relief.
During the study, patients in the CMM-only group continued to take morphine or similar narcotic drugs by mouth, plus additional medications as needed. Most IDDS patients received morphine via the pump; the others received hydromorphone (Dilaudid). IDDS patients could take additional narcotics by mouth if necessary.
At study entry, all trial participants rated their pain as well as the side effects of their pain medication (such as sedation, clouded thinking, constipation, and fatigue) on scales from 0 (least) to 10 (worst). Both the CMM-only group and the CMM-plus-IDDS group had average pain scores of more than 7.5 at the start of the trial.
But four weeks later, pain scores for IDDS patients fell to an average of 3.7 (a 51.5 percent reduction). In CMM patients, average pain scores dropped to 4.8 (a 39 percent reduction). IDDS patients also experienced a 50 percent reduction in toxic side effects after four weeks. By contrast, in patients who received CMM alone, toxic side effects declined by 17 percent.
When the researchers looked to see how many individuals in each group lowered their pain and side-effects scores by 20 percent or more, they found that 58 percent of patients using the implantable device had achieved this level of relief compared with 38 percent of patients who received CMM alone.
Survival rates also differed. After six months, 54 percent of patients using the implantable device were alive, compared with 37 percent of those in the CMM-only group. The better survival among users of the implantable device may be partly explained by the fact that they experienced a larger reduction in toxic side effects, say the investigators, who were led by Thomas J. Smith, M.D., of the Medical College of Virginia in Richmond.
As many as 15 percent of cancer patients have pain that is not relieved by conventionally delivered narcotic pain medications, note the researchers. Previous studies have shown that fear of the side effects of these medications is an important reason why many doctors fail to prescribe them and many patients decline to take them.
"This is a well-designed study that shows a modest but real benefit from the use of an implantable pump for control of cancer pain," commented Mitchell Max, M.D., a pain control specialist at the National Institute of Dental and Craniofacial Research in Bethesda, Maryland. He added, however, that it is premature to conclude that implantable pumps are better for all patients with difficult-to-treat cancer pain. "We need more research to better define which subgroups of cancer patients will benefit the most from using these devices."
Experimental Cancer Drug Tarceva
Reuters, October 9, 2002
NEW YORK (Reuters Health) - OSI Pharmaceuticals Inc. is more confident than ever of the potential of its experimental cancer drug Tarceva (erlotinib HCl), even after the failure of a similar drug in a major clinical study this summer, OSI Chairman and CEO Dr. Colin Goddard told investors at the UBS Warburg Global Life Sciences conference here on Wednesday.
In August, AstraZeneca Plc. announced that adding its investigational non-small cell lung cancer (NSCLC) drug Iressa to standard therapy did not improve survival in a phase III trial of patients who had failed prior chemotherapy. The news raised concerns about a new class of cancer drugs expected to be effective with fewer side effects than other therapies.
Iressa is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. These kinds of drugs are believed to cause fewer adverse events because they target specific proteins associated only with tumors.
Since Tarceva is also an EGFR inhibitor, many industry watchers began to worry that the drug, which is still being evaluated in a phase III trial of NSCLC patients, might also fail to meet expectations.
But Dr. Goddard dismissed these concerns on Wednesday, noting that while similar, Iressa and Tarceva are structurally different. But more importantly, he said, the companies' approaches in evaluating their respective drugs are very different, as well.
Dr. Goddard told Reuters Health that in its failed trial, AstraZeneca was using doses of Iressa one-third to two-thirds of the maximum tolerable dose. OSI is using the highest tolerated dose of Tarceva.
Interestingly, he said, one of the side effects of Tarceva treatment is rash, and "what we find is when we produce rash, patients tend to do very well. In other words, there's a suggestion that pushing dose has real benefit in terms of survival."
"Hence, our whole rationale and belief is that we will see a differentiation between
No comments:
Post a Comment