In 2012, the FDA approved the first new prescription weight loss drug in thirteen years: lorcaserin, marketed as Belviq.
Available to patients in the US since June 2013 in a twice-daily dose, it was soon (2016) followed by once-a-day Belviq XR.
Nevertheless, this herald of hope for almost one third of Americans rated as obese had a lamentably short lifespan: in February 2020, the FDA requested its voluntary withdrawal from the US market, prompted by a cardiovascular safety trial that instead indicated higher occurrences of cancers.
Discovered and developed by Arena Pharmaceuticals (headquartered in California), in 2017 all global development and marketing rights for a new chronic weight management treatment based on lorcaserin hydrochloride were acquired by Eisai Co., Ltd. (headquartered in Tokyo) and its pharmaceutical subsidiary in the USA: Eisai Inc.
Cancer + Cardio risks
Ironically enough, safety was touted as one of the main benefits of Belviq, stressing that it was neither a stimulant nor a narcotic.
An additional trial (run by Arena at the request of the FDA) indicated that Belviq would not cause heart problems at its low prescription dosages.
Originally conducted to assess cardiovascular risks, this randomized, double-blind, placebo-controlled clinical trial was conducted over five years with 12,000 patients.
However, researchers subsequently found that more patients taking this drug were diagnosed with a variety of cancers at rates higher than their counterparts taking placebos.
Their studies indicated increased risks of pancreatic, colorectal and lung cancers, based on the data drawn from this five-year cardiovascular risk study.
Furthermore, lorcaserin is classified as a Schedule IV controlled substance.
The Drug Enforcement Agency (DEA) mentions the risk of dependence, with overdoses possibly causing euphoria, sluggish thinking and hallucinations, in addition to interacting adversely with other medications.
Back the early 2010s, when the outlook for lorcaserin was burgeoning in a steadily fattening world, Eisai also took over Arena’s exclusive Belviq development, marketing and distribution agreements in South Korea, Taiwan and Israel.
In 2016, lorcaserin was approved by the Brazilian and Mexican authorities, later launched in Mexico as Venespri and Vigitel in Brazil.
In late 2018, Eisai signed a Belviq distribution and marketing agreement with Brazilian pharma giant Eurofarma Laboratórios covering eighteen countries in the Caribbean, Central and South America (Argentina, Bolivia, Brazil, Colombia, Ecuador, Mexico, Paraguay, Peru, Uruguay and Venezuela; Belize, Costa Rica, Dominican Republic, El Salvador, Guatemala, Honduras, Nicaragua and Panama).
This exclusive deal was intended to leverage Eurofarma’s solid business foundation throughout Latin America into a springboard speeding up the delivery of lorcaserin Hcl throughout this region.
However, this entire global marketing and development strategy was shot down by the FDA warning of possible cancer risks associated with lorcaserin, announcing a review of clinical trial data in January 2020.
Already rejected by the European Medicines Agency in 2012, due to concerns over its safety, reactions to this latest FDA ban should be expected in other countries over the coming months.
Brazil’s Public Health Regulator (ANVISA) has already recommended that physicians cease prescribing lorcaserin, due to potential neoplasia risks.
It is currently reassessing the safety data, seeking further input for a decision on whether or not to keep this product on the Brazilian market.
There seems little doubt that the rest of the world will soon follow suit.
Why is approval so hard for diet pills?
The recent history of weight loss remedies has been plagued by safety issues.
Since 1999, when Xenical (orlistat) was given the green light, Meridia (sibutramine) has been taken off the market due to rising risks of heart problems, and Qnexa was rejected by the FDA because of safety concerns.
Tweaking the body’s natural weight control mechanisms can have severe consequences on the cardiovascular system and other metabolic aspects.
The FDA and its sister agencies all over the world must weigh diet pill benefits against the risks that they offer, imposing stringent safety requirements on drug developers.
No magic bullet
Even apparently safe herbal options can be dangerous.
Popular a couple of decades ago, supplements containing ephedra caused serious side effects, including strokes, heart attacks and even deaths.
Although ma huang is a mainstay of traditional Chinese medicine, the FDA banned these OTC weight loss favorites in 2004.
Back in the 1960s, Aminorex was an OTC appetite suppressant resembling amphetamine.
Before being outlawed in 1972, it triggered an epidemic of pulmonary hypertension in Germany, Switzerland and Austria.
Approved in 2006 in Europe (but never in the USA) and sold widely as Acomplia, rimonabant caused serious psychiatric side effects, particularly depression and suicidal ideation.
Associated with seven deaths and 2,500 adverse reactions, it was banned by the European Medicines Agency in 2008.
Yanked from the market in 1977 because of adverse effects that included pulmonary hypertension and heart valve disease, serotonin-based fenfluramine was half of the once-popular combo appetite suppressant known as fen-phen.
However, phentermine is still prescribed (as Adipex-P and Lomaira) as a short-term weight loss solution, despite its cardio risks and inclusion in the now-banned Qnexa.
How does Belviq work?
An appetite suppressant, lorcaserin activates brain receptors for serotonin, triggering feelings of fullness and satisfaction in the hunger-controlling part of the brain, known as the hypothalamus.
Like many antidepressants, it keeps the brain receptors bathed in this feel-good chemical.
Designed specifically for chronic weight management among obese adults or overweight patients with at least one comorbidity, (such as hypertension, type II diabetes or high cholesterol), it is prescribed as part of a healthy diet and exercise program.
If a patient fails to lose 5% body weight in twelve weeks, the medication should be discontinued.
The most common side effects of Belviq among non-diabetic patients are headache, dizziness, nausea, drowsiness, dry mouth, muscle pain confusion and constipation.
For more vulnerable patients with diabetes, side effects include low blood sugar, headache, back pain, cough and fatigue.
Looking at the severe and unexpected side-effects built up by assorted weight control medications over the past few decades, it is clear why only a few options are still approved for this massive global market.
Based on this disturbing track record, it seems clear that ever-hopeful dieters are spiralling right back to those boring old basics: a lo-cal diet and regular exercise.
Set to rank as the world’s second-most popular little blue pill only a few weeks ago, patients are now advised to come off lorcaserin immediately, exploring other weight loss options with their physicians.
And after Belviq patients have contacted their physicians, they might well consider calling their lawyers for advice too.