SAN DIEGO, March 30 -- Nearly half -- 47.5% -- of patients taking the investigational weight-loss drug lorcaserin lost at least 5% of their body weight compared with 20.3% of patients in the placebo group (P<0.0001), Arena Pharmaceuticals announced today.
The company said patients in its pivotal trial -- BLOOM (Behavioral modification and Lorcaserin for Overweight and Obesity Management) -- lost an average of 12.7 pounds, which was 5.8% of body weight compared with a 4.7-pound (2.2% of body weight) loss in the placebo arm.
Furthermore, Arena said 22.6% of lorcaserin patients lost 10% or more of their body weight from baseline, compared with 7.7% in the placebo group (P<0.0001).
As readers of MedPageToday know, I participated in a year-long weight-loss trial -- the drug that was being studied was Arena's lorcaserin.
I wasn't in the trial that was the subject of today's announcement -- mine required that participants have diabetes and one other cardiovascular risk factor -- but I, too, had good results.
I've completed my participation in the trial, and I'm still blinded to my therapy, but I lost 52 pounds -- 18.4% of my baseline body weight.
During the trial, my diabetes improved to the point where I was able to discontinue -- with physician approval -- three of the four oral diabetes medications I was taking at the start of treatment.
Despite the positive findings announced today, the results were not well received in financial quarters, where Arena's shares dropped 34% by midday.
"Although the results technically satisfy the FDA requirements for approvability, we consider the weight loss benefits to be underwhelming at best," JPMorgan said in a research note.
The researchers, however, were more upbeat.
"The BLOOM results, demonstrating lorcaserin's medically important weight loss coupled with the tolerability and safety profile displayed in this trial, differentiate lorcaserin from approved drugs or other agents in clinical trials," said Steven R. Smith, M.D., of Louisiana State University in Baton Rouge, who was the principal investigator in the trial.
The company statement reported that lorcaserin was generally very well tolerated.
The most frequent adverse events reported in the first year and their rates for lorcaserin and placebo patients, respectively, were headache (18.0% vs. 11.0%), upper respiratory tract infection (14.8% vs. 11.9%), nasopharyngitis (13.4% vs. 12.0%), sinusitis (7.2% vs. 8.2%), and nausea (7.5% vs. 5.4%).
During my 52 weeks in the trial I did not notice any adverse side effects.
Adverse events of depression, anxiety, and suicidal ideation were infrequent and reported at a similar rate in each treatment group, and no seizures were reported.
Serious adverse events occurred with similar frequency in each group throughout the trial without apparent relationship to lorcaserin. One death occurred during the trial, which was a patient in the placebo arm.
One concern of doctors, the Food and Drug Administration, and patients in the lorcaserin trials is the possibility of heart valve problems.
The assessment of echocardiograms performed at baseline and after patients completed six, 12, 18 and 24 months of dosing indicated no apparent drug-related effect on the development of FDA-defined valvulopathy, the company said.