By Amy Norton
MONDAY, Nov. 10, 2014 (HealthDay News) -- A combination of drugs may offer a better way to combat a serious kidney complication that commonly affects people with lupus, a new study from China suggests.
In a trial of more than 300 Chinese patients with the condition, known as lupus nephritis, those who were given a trio of powerful drugs were more likely to see a complete remission. After six months, 46 percent were in full remission, versus 26 percent of patients given an intravenous drug called cyclophosphamide.
"These are important results," said Dr. David Wofsy, a rheumatologist at the University of California, San Francisco, who was not involved in the study.
But there are some big questions that still need to be answered, he added.
One is whether lupus patients of other races and ethnicities would get the same benefits as these Chinese patients. The genetics of lupus vary, Wofsy explained, and researchers know from experience that a treatment can work well for one ethnic group, but not others.
"We need to proceed with caution," Wofsy said. "This is a first step, and we'll need to see these results replicated in other patient groups."
The researchers, led by Dr. Zhihong Liu of Nanjing University School of Medicine in China, reported the findings online Nov. 10 in the Annals of Internal Medicine.
Lupus is an autoimmune disease in which the immune system attacks tissue throughout the body, including the skin, joints, heart, lungs and kidneys. It's often first diagnosed in women in their 20s and 30s, and is more common among Asian, black and Hispanic people than whites, according to the Lupus Foundation of America.
Up to 60 percent of people with the disease develop lupus nephritis, according to the U.S. National Institutes of Health.
"Nephritis is the most common of the dreaded life-threatening complications that can affect people with lupus," Wofsy said.
But right now, he added, there are no drugs approved specifically to treat lupus nephritis. "So we try what we can," Wofsy said.
Two drugs that suppress the immune system -- intravenous cyclophosphamide and mycophenolate mofetil (MMF), an oral drug -- have become the standard treatments, Wofsy said.
But for many people, he explained, those medications alone don't put the kidney disease into remission -- or the side effects are too harsh for patients to tolerate.
And because of those side effects, Wofsy noted, doctors have been "hesitant" to try combining different immune-suppressing drugs to boost the chances of remission.
But in the new study, Liu's team did just that. They randomly assigned patients with lupus nephritis to one of two groups: One received monthly infusions of cyclophosphamide, plus oral steroid medication to ease their kidney inflammation; the other received oral steroids, along with two immune-suppressing medications -- MMF and tacrolimus.
After six months, 46 percent of patients on the drug trio were in complete remission, and 84 percent had at least a partial response -- meaning their kidney function had improved, according to the study.
In contrast, just under 26 percent of patients on cyclophosphamide were in complete remission. And 63 percent had at least a partial response, the researchers found.
"This is encouraging, in showing that combination therapy may have better efficacy," said Dr. Gary Gilkeson, a rheumatologist at the Medical University of South Carolina, in Charleston. "It will definitely lead to further studies."
But Gilkeson, who was not involved in the study, agreed that the results have to be replicated in other racial and ethnic groups.
He said one of the worries with giving multiple drugs is that it will boost the risk of side effects -- which, depending on the medication, can include infections, tremors, diarrhea, nausea and sleep problems.
In this study, about half of patients in each group had a serious side effect, according to Liu's team.
"So the toxicity was equivalent," Gilkeson said. "But everybody is looking for less toxicity. And we don't know what the long-term effects could be if this were continued beyond six months."
One potential side effect is high blood pressure, he noted, which can actually damage the kidneys.
Another unknown, according to Gilkeson, is whether patients with severe nephritis can benefit from the drug combination.
"This study didn't include patients with severe disease," he said. "So we don't know yet if the results would translate to them."