"The great thing is that the study collected blood and they are able to look at carnitine levels," Dr. Barton said. "So if carnitine is up in the group that got acetyl-carnitine and not in the group that got placebo, well, I think that pretty much confirms that this just didn’t work."
ALC for Treatment of Peripheral Neuropathy
In the second trial, protocol ZHAOKE-2007L03540, investigators led by Dr. Yuanjue Sun of the Sixth Affiliated Hospital of Shanghai (China) Jiao Tong University, enrolled 239 patients who had cancer of various types and stages, had completed chemotherapy, and had had at least grade 2 peripheral neuropathy for up to 6 months.
They were randomly assigned to receive either oral ALC at a dose of 3 g/day or matching placebo, for 8 weeks, with outcomes assessed at clinic visits or by telephone.
Analyses showed that compared with their counterparts in the placebo group, patients in the ALC group were more likely to have had an improvement of at least one grade in their neuropathy, both at 8 weeks (51% vs. 24%; P less than .001) and at 12 weeks (58% vs. 40%; P less than .001).
In terms of secondary outcomes, the ALC group was also more likely to have had an improvement in cancer-related fatigue (31% vs. 20%; P = .048), physical strength (29% vs. 13%; P = .02), and electrophysiology in peripheral nerves (75% vs. 58%; P = .02).
The two groups had statistically indistinguishable rates of adverse events (20% vs. 15%) and adverse reactions (6% vs. 5%). The most common events were gastrointestinal ones and skin allergies.
"This is the first time to confirm that ALC has a positive effect to cure chemotherapy-induced peripheral neuropathy in the Chinese population," Dr. Sun commented through a translator.
"I think the very important thing for this trial is, it is a different kind of patient population. Before this, most clinical trials were performed in [whites] or maybe Americans. This is an only-Asian [population]," he noted, and it is possible that there are genetic differences in how ALC is metabolized.
Dr. Barton, the discussant, took a cautionary view, saying that "there are some things to consider before going out and telling patients to consider acetyl-carnitine for their peripheral neuropathy."
It was unclear from the results reported whether the two treatment groups were well balanced and what criteria were used to define improvement for the secondary outcomes, she noted. Additionally, "outcome measures were all provider graded, [and there were] no self-report measures, so it is difficult to understand the impact of treatment on symptoms, particularly from the patient perspective," she noted.
Dr. Hershman, Dr. Sun, and Dr. Barton disclosed no relevant conflicts of interest; the ZHAOKE-2007L03540 trial was sponsored by Lee’s Pharmaceutical Limited.