Human Genome Calls Second Lupus Drug Study a Success
ROCKVILLE, Md. (
) --
Human Genome Sciences
(HGSI)
announced positive results Monday from a second pivotal study of its experimental lupus drug Benlysta, although the drug did not perform as well as it did in the first study.
Still, the company along with partner
GlaxoSmithKline
(GSK) - Get Report
said they plan to seek regulatory approval for Benlysta in the U.S. and Europe during the first half of next year. If approved, Benlysta will become the first new lupus drug to reach the market in more than four decades.
Regulators require two positive clinical trials of a lupus drug for approval, so investors have waited nervously for Monday's results from the so-called Bliss-76 study of Benlysta ever since the positive data from the first study -- Bliss-52 -- were released in July.
July's trial was a unambiguous success, Bliss-76 less so. Human Genome reported Monday that 43.2% of lupus patients responded to treatment with a high dose of Benlysta after one year compared to 33.8% of patients treated with a placebo -- a difference that was statistically significant for the trial's primary endpoint.
However, a lower dose of Benlysta only benefited 40.6% of lupus patients after one year and that difference was not statistically significant compared to placebo.
In the
, patients treated with both the high and low doses of Benlysta achieved a statistically significant response over placebo.
Likewise, mixed results were also reported from the study's key secondary endpoint. The high dose of Benlysta demonstrated a statistically significant decrease versus placebo in a scale of lupus disease activity, but the low dose did not.
Neither the high or low doses of Benlysta were able to demonstrate an improvement versus placebo in a physician's rating of lupus patients' overall health, a reduction in steroid use or a quality of life assessment tool.
Human Genome said that the rates of serious adverse events were similar in the Benlysta and placebo arms of the study. The rate of serious infections was actually a bit lower in Benlysta patients than placebo patients. However, five patients treated with Benlysta were diagnosed with cancer compared to a single placebo patients and three Benlysta patient died during the study compared to no placebo patients.
The Bliss-76 study enrolled 819 lupus patients primarily in North America and Europe. The study was similar to the earlier Bliss-52 trial except patients mainly came from Asia, South America and Easter Europe.
Better medical care for lupus patients in Europe and North America may have played a role in explaining the differences observed in the two Benlysta clinical trials.
Benlysta is a human monoclonal antibody designed to recognize and tamp down the biological activity of B-lymphocyte stimulator, or BLyS, a substance that was discovered by Human Genome. High levels of BLyS plays a role in the development of abnormal B cells (B cells are a component of the immune system), and abnormal B cells lead to increased auto-antibody formation.
Benlysta appears to lower levels of BLyS and therefore stop young B cells from growing abnormally. One advantage to treating lupus with this approach is that Benlysta doesn't appear to affect more mature B cells, which are an important part of a patient's immune system.
Rituxan, the blockbuster cancer and autoimmune disease drug from
Roche/Genentech
and
Biogen Idec
(BIIB) - Get Report
, works by depleting all B cells, but the drug has so far proved ineffective in lupus.
Benlysta is the first blockbuster drug to step out from Human Genome's labs. There are between 300,000 and 400,000 lupus patients in the U.S., with similar numbers in Europe. Not all these patients are sick enough or ideally suited for treatment with Benlysta, but the drug's peak revenue could still top $1 billion annually.
Human Genome shares closed Friday at $18.69.
-- Reported by Adam Feuerstein in Boston
Adam Feuerstein writes regularly for TheStreet.com. In keeping with TSC's editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet.com. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback;
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