The New Obesity Breakthrough Drugs

There are many holy grails in medicine, with failure after failure, like finding a way to prevent Alzheimer's disease or a non-invasive means for accurately measuring ambulatory blood pressure. But one of the biggest and most daunting has been finding drugs that can tackle obesity — achieving a substantial amount of weight loss without serious side effects. Many attempts to get there now fill a graveyard of failed drugs, such as fen-phen in the 1990s when a single small study of this drug combination in 121 people unleashed millions of prescriptions, some leading to serious heart valve lesions that resulted in withdrawal of the drug in 1995. The drug rimonabant, an endocannabinoid receptor blocker (think of blocking the munchies after marijuana) looked encouraging in randomized trials. However, subsequently, in a trial that I led of nearly 19,000 participants in 42 countries around the world, there was a significant excess of depression, neuropsychiatric side-effects and suicidal ideation which spelled the end of that drug's life.

 

In the United States, where there had not been an anti-obesity drug approved by the FDA since 2014, Wegovy (semaglutide), a once-weekly injection was approved in June 2021. The same drug, at a lower dose, is known as Ozempic (as in O-O-O, Ozempic, the ubiquitous commercial that you undoubtedly hear and see on TV) and had already been approved in January 2020 for improving glucose regulation in diabetes. The next drug on fast track at FDA to be imminently approved is tirzepatide (Mounjaro) following its approval for diabetes in May 2022. It is noteworthy that the discovery of these drugs for weight loss was serendipitous: they were being developed for improving glucose regulation and unexpectedly were found to achieve significant weight reduction.

Both semaglutide and tirzepatide underwent randomized, placebo-controlled trials for obesity, with marked reduction of weight as shown below. Tirzepatide at dose of 10 to 15 mg per week achieved >20% body weight reduction. Semaglutide at a dose of 2.4 mg achieved ~17% reduction. These per cent changes in body weight are 7-9 fold more than seen with placebo (2-3% reduction). Note: these levels of per cent body weight reduction resemble what is typically achieved with the different types of bariatric surgery, such as gastric bypass.

 

Another way to present the data for the 2 trials is shown here, with an edge for tirzepatide at high (10-15 mg) doses, extending to >25% body weight reduction.

 

 

The results with semaglutide were extended to teens in a randomized trial (as shown below), and a similar trial with tirzepatide is in progress.

 

How Do These Drugs Work?

 

These are peptides in the class of incretins, mimicking gut hormones that are secreted after food intake which stimulate insulin secretion.

 

These 2 drugs have in common long half-lives (~ 5 days), which affords once-weekly dosing, but have different mechanisms of action. Semaglutide activates (an agonist) the GLP-1 receptor, while tirzepatide is in a new class of dual agonists: it activates (mimics) both the GLP-1 receptor and GIP receptors (Gastric inhibit polypeptide is also known as glucose-dependent insulinotropic polypeptide.) The potency of activation for tirzepatide is 5-fold more for GIPR than GLP1. As seen below, there are body wide effects that include the brain, liver, pancreas, stomach, intestine, skeletal muscle and fat tissue. While their mode of action is somewhat different, their clinical effects are overlapping, which include enhancing satiety, delaying gastric emptying, increasing insulin and its sensitivity, decreasing glucagon, and, of course, reducing high glucose levels. The overlap extends to side effects of nausea, vomiting, abdominal pain, constipation and diarrhea. Yet only 4 to 6% of participants discontinued the drug in these trials, mostly owing to these GI side effects (and 1-2% in the placebo group discontinued the study drug for the same reasons).

In randomized trials among people with Type 2 diabetes, the drugs achieved HbA1c reduction of at least an absolute 2 percentage points which led to their FDA approvals (For semaglutide in January 2020, and for tirzepatide in May 2022). The edge that tirzepatide has exhibited for weight loss reduction may be related to its dual agonist role, but the enhancement via GIP receptor activation is not fully resolved (as seen below with GIP? designation). The Amgen drug in development (AMG-133) has a marked weight loss effect but inhibits GIP rather than mimics it, clouding our precise understanding of the mechanism.

 

The gut-brain regulation of food intake with the many gut hormones (including leptin, gherlin, PYY, amylin) and targets in the body and brain regions. From Muller et al, Nature Reviews Drug Discovery March 2022. 

Nevertheless, when the two drugs were directly compared in a randomized trial for improving glucose regulation, tirzepatide was superior to semaglutide, as shown below. Of note, both drugs achieved very favorable effects on lipids, reducing triglycerides, LDL and raising HDL cholesterol, along with reduction of blood pressure, an outgrowth of the indirect effect of weight reduction and direct metabolic effects of the drugs.

 

While there has been a concern about other side effects besides the GI ones noted above, review of all the trials to date in these classes of medication do not reinforce a risk of acute pancreatitis. Other rare side effects that have been noted with these drugs include allergic reactions, gallstones (which can occur with a large amount of weight loss), and potential of medullary thyroid cancer (so far only documented in rats, not people), which is why they are contraindicated in people with Type 2 multiple endocrine neoplasia syndrome.

How They Are Given and Practical Considerations

 

For semaglutide, which has FDA approval, the indication is a BMI of 30 kg/m2 or greater than 27 kg/m2 and a weight related medical condition (such as hypertension. hypercholesterolemia or diabetes). To reduce the GI side effects, which mainly occur in the early dose escalation period, semaglutide is given in increasing doses by a prefilled pen by self-injection under the skin (abdomen, thigh or arm) starting at 0.25 mg for a month and gradual increases each month reaching the maximum dose of 2.4 mg at month 5. The FDA label for dosing of tirzepatide has not been provided yet but in the weight loss trial there was a similar dose escalation from 2.5 mg up to 15 mg by month 5. The escalation is essential to reduce the frequent GI side effects, such as seen below in the tirzepatide trial.

 

Semaglutide is very expensive, ~$1500 per month, and not covered by Medicare. There are manufacturer starter coupons from Novo Nordisk, but that is just for the first month. These drugs have to be taken for a year to 18 months to have their full effect and without changes in lifestyle that are durable, it is likely that weight will be regained after stopping them.

What Does This Mean?

 

More than 650 million adults are obese and 13% of the 8 billion world's population (including over 340 million ages 5-18) is obese — that sums us to over 1 billion people. The global obesity epidemic has been relentless, worsening each year, and a driver of "diabesity," the combined dual epidemic. We now have a breakthrough class of drugs that can achieve profound weight loss equivalent to bariatric surgery, along with the side benefits of reducing cardiovascular risk factors (hypertension and hyperlipidemia), improving glucose regulation, reversing fatty liver, and the many detrimental long-term effects of obesity such as osteoarthritis and various cancers. That, in itself, is remarkable. Revolutionary.

 

But the downsides are also obvious. Self-injections, even though they are once a week, are not palatable for many. We have seen far more of these injectables in recent years such as the PCSK-9 inhibitors for hypercholesterolemia or the TNF blockers for autoimmune conditions. That still will not make them a popular item for such an enormous population of potential users.

That brings me to Rybelsus, the oral form of semaglutide, which is approved for glucose regulation improvement but not obesity. It effects for weight loss have been modest compared to Wegovy (5 to 8 pounds for the 7 and 14 mg dose, respectively). But the potential for the very high efficacy of an injectable to be achievable via a pill represents an important path going forward—it could help markedly reduce the cost and uptake.

The problem of discontinuation of the drugs is big, since there are limited data and the likelihood is that the weight will be regained unless there are substantial changes in lifestyle. We know how hard it is to durably achieve such changes, along with the undesirability (and uncertainty with respect to unknown side-effects) of having to take injectable drugs for many years, no less the cost of doing that.

The cost of these drugs will clearly and profoundly exacerbate inequities, since they are eminently affordable by the rich, but the need is extreme among the indigent. We've already seen celebrities take Wegovy for weight loss who are not obese, a window into how these drugs can and will be used without supportive data. As one physician recently observed, "Other than Viagra and Botox, I've seen no other medication so quickly become part of modern culture's social vernacular." Already there are concerns that such use is preventing access to the drugs for those who qualify and need them.

 

There are multiple agents in the class under development which should help increase competition and reduce cost, but they will remain expensive. There is private insurance reimbursement, often with a significant copay, for people who tightly fit the inclusion criteria. Eventual coverage by Medicare will markedly expand their use, and we can expect cost-effectiveness studies to be published showing how much saving there is for the drugs compared with bariatric surgery or not achieving the weight loss. But that doesn't change the cost at the societal level. Even as we've seen with generics, which will ultimately be available, the alleviation of the cost problem isn't what we'd hoped.

 

This is not unlike the recent triumphs of gene therapy, as in $3.5 million for a cure of hemophilia that just got FDA approval, but instead of a rare disease we are talking about the most common medical condition in the world. We finally get across the long sought after (what many would qualify as miraculous) goal line, but the economics collide with the uptake and real benefit.

 

These concerns can't be put aside in the health inequity-laden world we live in, that will unquestionably be exacerbated. However, we cannot miss that this represents one of the most important, biggest medical breakthroughs in history. This may signify the end or marked reduction in the need for bariatric surgery. These drugs will likely become some of the most prescribed of all medications in the upcoming years. While there are many drawbacks, we shouldn't miss such an extraordinary advance in medicine—the first real, potent and safe treatment of obesity.

Can Particles in Dairy and Beef Cause Cancer and MS?

In our Western diet, dairy and beef are ubiquitous: Milk goes with coffee, melted cheese with pizza, and chili with rice. But what if dairy products and beef contained a new kind of pathogen that could infect you as a child and trigger cancer or multiple sclerosis (MS) 40-70 years later?

Researchers from the German Cancer Research Center(DKFZ) suspect that such zoonoses are possibly widespread and are therefore recommending that infants not be given dairy products until they are at least age 1 year. However, in two joint statements, the German Federal Institute for Risk Assessment (BfR) and the Max Rubner Institute (MRI) have rejected such theories.

In 2008, Harald zur Hausen, MD, DSc, received the Nobel Prize in Medicine for his discovery that human papillomaviruses cause cervical cancer. His starting point was the observation that sexually abstinent women, such as nuns, rarely develop this cancer. So it was possible to draw the conclusion that pathogens are transmitted during sexual intercourse, explain zur Hausen and his wife Ethel-Michele de Villiers, PhD, both of DKFZ Heidelberg.

Papillomaviruses, as well as human herpes and Epstein-Barr viruses (EBV), polyomaviruses, and retroviruses, cause cancer in a direct way: by inserting their genes into the DNA of human cells. With a latency of a few years to a few decades, the proteins formed through expression stimulate malignant growth by altering the regulating host gene.

Acid Radicals 

However, viruses — just like bacteria and parasites — can also indirectly trigger cancer. One mechanism for this triggering is the disruption of immune defenses, as shown by the sometimes drastically increased tumor incidence with AIDS or with immunosuppressants after transplants. Chronic inflammation is a second mechanism that generates acid radicals and thereby causes random mutations in replicating cells. Examples include stomach cancer caused by Helicobacter pyloriand liver cancer caused by Schistosoma, liver fluke, and hepatitis B and C viruses.

According to de Villiers and zur Hausen, there are good reasons to believe that other pathogens could cause chronic inflammation and thereby lead to cancer. Epidemiologic data suggest that dairy and meat products from European cows (Bos taurus) are a potential source. This is because colon cancer and breast cancer commonly occur in places where these foods are heavily consumed (ie, in North America, Argentina, Europe, and Australia). In contrast, the rate is low in India, where cows are revered as holy animals. Also noteworthy is that women with a lactose intolerance rarely develop breast cancer.

Viral Progeny 

In fact, the researchers found single-stranded DNA rings that originated in viruses, which they named bovine meat and milk factors (BMMF), in the intestines of patients with colon cancer. They reported, "This new class of pathogen deserves, in our opinion at least, to become the focus of cancer development and further chronic diseases." They also detected elevated levels of acid radicals in these areas (ie, oxidative stress), which is typical for chronic inflammation.

The researchers assume that infants, whose immune system is not yet fully matured, ingest the BMMF as soon as they have dairy. Therefore, there is no need for adults to avoid dairy or beef because everyone is infected anyway, said zur Hausen in a speech.

'Breast Milk Is Healthy'

De Villiers and zur Hausen outlined more evidence of cancer-triggering pathogens. Mothers who have breastfed are less likely, especially after multiple pregnancies, to develop tumors in various organs or to have from MS and type 2 diabetes. The authors attribute the protective effect to oligosaccharides in breast milk, which begin to be formed midway through the pregnancy. They bind to lectin receptors and, in so doing, mask the terminal molecule onto which the viruses need to dock. As a result, their port of entry into the cells is blocked.

The oligosaccharides also protect the baby against life-threatening infections by blocking access by rotaviruses and noroviruses. In this way, especially if breastfeeding lasts a long time — around 1 year — the period of incomplete immunocompetence is bridged.

Colon Cancer 

To date, it has been assumed that around 20% of all cancerous diseases globally are caused by infections, said the researchers. But if the suspected BMMF cases are included, this figure rises to 50%, even to around 80%, for colon cancer. If the suspicion is confirmed, the consequences for prevention and therapy would be significant.

The voice of a Nobel prize winner undoubtedly carries weight, but at the time, zur Hausen still had to convince a host of skeptics with his discovery that a viral infection is a major cause of cervical cancer. Nonetheless, some indicators suggest that he and his wife have found a dead end this time.

Institutional Skepticism 

When his working group made the results public in February 2019, the DKFZ felt the need to give an all-clear signal in response to alarmed press reports. There is no reason to see dairy and meat consumption as something negative. Similarly, in their first joint statement, the BfR and the MRI judged the data to be insufficient and called for further studies. Multiple research teams began to focus on BMMF as a result. In what foods can they be found? Are they more common in patients with cancer than in healthy people? Are they infectious? Do they cause inflammation and cancer?

The findings presented in a second statement by the BfR and MRI at the end of November 2022 contradicted the claims made by the DKFZ scientists across the board. In no way do BMMF represent new pathogens. They are variants of already known DNA sequences. In addition, they are present in numerous animal-based and plant-based foods, including pork, fish, fruit, vegetables, and nuts.

BMMF do not possess the ability to infect human cells, the institutes said. The proof that they are damaging to one's health was also absent. It is true that the incidence of intestinal tumors correlates positively with the consumption of red and processed meat — which in no way signifies causality — but dairy products are linked to a reduced risk. On the other hand, breast cancer cannot be associated with the consumption of beef or dairy.

Therefore, both institutes recommend continuing to use these products as supplementary diet for infants due to their micronutrients. They further stated that the products are safe for people of all ages.

Association With MS? 

Unperturbed, de Villiers and zur Hausen went one step further in their current article. They posited that MS is also associated with the consumption of dairy products and beef. Here too geographic distribution prompted the idea to look for BMMF in the brain lesions of patients with MS. The researchers isolated ring-shaped DNA molecules that proved to be closely related to BMMF from dairy and cattle blood. "The result was electrifying for us."However, there are several other factors to consider, such as vitamin D3 deficiency. This is because the incidence of MS decreases the further you travel from the poles toward the equator (ie, as solar radiation increases). Also, the EBV clearly plays a role because patients with MS display increased titers of EBV antibodies. One study also showed that people in Antarctica excreted reactivated EBV in their saliva during winter and that vitamin D3 stopped the viral secretion.

Under these conditions, the researchers hypothesized that MS is caused by a double infection of brain cells by EBV and BMMF. EBV is reactivated by a lack of vitamin D3, and the BMMF multiply and are eventually converted into proteins. A focal immunoreaction causes the Schwann cells and oligodendrocytes to malfunction, which leads to the destruction of the myelin sheaths around the nerve fibers.