While beneficial for patients with prior weight loss, ruxolitinib can cause significant weight gain (20-30 pounds) in other myelofibrosis patients. This quality-of-life issue should be discussed proactively, as it can become a major concern, effectively trading one disease state for another.

When stopping GLP-1 drugs like Ozempic, hunger doesn't just return to normal; it comes back with a "ferocious, animalistic" vengeance that is far more intense than before starting the medication. This powerful rebound effect is a primary driver of rapid weight regain.

Contrary to early beliefs, drugs like Ozempic's main effect is on GLP-1 receptors in the brain, not the gut. This changes how the brain functions, representing a more intimate and potentially riskier intervention that could trigger psychological side effects or, conversely, treat addiction.

GPRC5D-targeting bispecifics like talquetamab require a specific learning curve due to their unique 'on-target, off-tumor' side effects. Because the GPRC5D target is also present on skin and taste bud tissues, patients can experience significant dysgeusia, skin changes, and nail toxicities that require active management.

Early retrospective data from major cancer centers suggests patients on hormone therapy experience less weight loss with GLP-1 agonists. This indicates a potential drug interaction that may require clinicians to more closely monitor weight trends and consider dose adjustments for this patient population.

Next-gen ROS1 inhibitors like repotrectinib also inhibit the TRK protein, leading to a highly unusual side effect: severe, full-body withdrawal pain if the drug is held for surgery or radiation. The pain, which resolves within hours of restarting the pill, highlights a unique withdrawal phenomenon clinicians must anticipate.

Patients often worry that anti-estrogen therapies directly cause weight gain. However, the mechanism is more nuanced: the drugs induce a postmenopausal state characterized by inflammation and metabolic dysfunction, which, combined with natural aging, makes weight gain more likely and weight loss more difficult.

Despite showing massive weight loss, new obesity drugs from Eli Lilly and others have high discontinuation rates due to side effects. This suggests the industry's singular focus on efficacy may be hitting diminishing returns, opening a new competitive front based on better patient tolerance and adherence.

When you stop taking GLP-1 medications and regain weight, the new weight is primarily fat, not the lean muscle you lost. Each on-off cycle progressively shifts your body composition unfavorably, making you metabolically worse off than before starting.