Marisa Wexler, MS, senior science writer —

Marisa holds a Master of Science in cellular and molecular pathology from the University of Pittsburgh, where she studied novel genetic drivers of ovarian cancer. Her areas of expertise include cancer biology, immunology, and genetics, and she has worked as a science writing and communications intern for the Genetics Society of America.

Articles by Marisa Wexler

Study Identifies Possible Genetic Causes of MS

Scientists are zeroing in on mutations in a few genes that appear to be major risk factors for developing multiple sclerosis (MS). The results of their research suggest there are common biological pathways that cause the disease. The study, “Exome sequencing in multiple sclerosis families identifies 12…

#AANAM – Ocrevus Effective in RRMS Patients with Poor Responses to Other DMTs, Early Trial Data Suggest

Early, one-year data from theĀ Phase 3 CHORDS study show that OcrevusĀ effectively prevents relapses and disease progression inĀ relapsing-remitting multiple sclerosis (RRMS) patients who have had poor responses to other disease-modifying therapies. These interim results were presented at the 2019 annual meeting of the American Academy of NeurologyĀ (AAN) in…

#AANAM – Research Suggests Extended Interval Dosing of Tysabri Can Decrease Risk of PML

New data suggests that treatment withĀ TysabriĀ (natalizumab) in an extended interval dosing regimen is associated with a significantly lower risk ofĀ progressive multifocal leukoencephalopathyĀ (PML) in patients with multiple sclerosis (MS), compared with the standard interval dosing. The data was presented byĀ Lana Zhovtis Ryerson, MD, on May 7 at the 2019Ā …

#AANAM – Precision Innovative Network and Splice Machine Will Present Predictive Healthcare Application at AAN Meeting

A new clinical application prototype that uses machine learning to help physicians predict the best treatment options for patients with multiple sclerosis (MS) will be unveiled at theĀ American Academy of Neurology’s 2019 annual meetingĀ May 4ā€“10, in Philadelphia, Pennsylvania. The prototype is called PIN Population Data Platform. It has been…

Excess Body Fat Spurs Disease Progression by Impact on Immune Cells, Study Suggests

A link between fat molecules calledĀ ceramides andĀ worsening disease in overweight and obese people with multiple sclerosis appears to exist, a study reports, with its findings suggesting that ceramides prompt the growth of immune cells calledĀ monocytes, which in turn spurs disease progression. These results also strengthen the likelihood thatĀ lifestyle factors, like diet and weight, can act as disease modifiers, its researchers said. High body mass index has been linked to the risk of developing MS, but for reasons that aren't clear. One idea is that weight-induced differences in lipids (fat molecules) in the blood, because they are involved in several cellular signaling processes, may affect MS and its course in people with higher BMIs. To test this hypothesis, a team led by researchers atĀ the Advanced Science Research Center (ASRC) at The Graduate Center and at the Icahn School of Medicine at Mount Sinai analyzed 54 patients with relapsing-remitting MS (MS), ages 18 to 60, and with normal or high BMIs (27 people in each group). Participants were followed for two years. BMI is a measure of body fat based on height and weight. A normal BMI is defined as one between 18.5 and 24.9, while a person is considered overweight with a BMI of 25ā€“29.9, and obese it is 30 or higher. Researchers took blood samples, and looked for differences between the groups in terms of both immune cells and blood lipid profiles. They then validated their findings in a separate group of 91 RRMS patients. Patients with high BMIs tended to have more monocytes than those with normal BMIs. Monocytes can travel through the blood to tissues where they develop into macrophages, immune cells with various functions that are best known for "eating" invading bacteria. Monocytes can also travel to the brain and damage nerve fibers. Overweight and obese patients also had significantly higher levels of ceramides compared with normal-weight patients, and the researchers wondered if a link might exist between the two. Through a set of experiments in cells, they discovered that ceramides cause epigenetic changes in monocytes; that is, they alter the way their genomes are "read," so they alter gene activity. Specifically, ceramide-treated cells showed a type of epigenetic change called methylation ā€” which generally turns genes "off" ā€” in genes that normally help prevent cells from dividing. Conceptually, these genetic changes serve to unleash monocytes, leading them to grow more (proliferate) than they otherwise might. The researchers also found more methylation on the genomes of monocytes from high-BMI patients than those from low-BMI patients, and they noted that the overweight or obese patients also tended to have greater disease activity, worse disability progression, and more brain lesions on MRI (magnetic resonance imaging) scans on follow-up. Finally, the researchers tested a mouse model of MS, giving one group of mice a standard diet and another a high-fat diet. Mice fed the high-fat diet were found to have greater disease severity, more brain lesions, and more monocytes, confirming the findings seen in MS patients. "This study gives us a much-needed view into the environmental influences that can affect and change the behavior of cells in an individual's body," Kamilah Castro, the study's first author, said in a press release. "Our findings suggest that increased levels of saturated fat as a result of dietary habits are one likely cause of the epigenetic changes that advance MS, which gives us a starting point for a potential intervention." According to the team, the findingsĀ support the concept of nutri-epigenomics:Ā that is, the ability of food to alter the way the genetic information is interpreted by each cell, and suggest that "weight management and dietary intervention" might affect MS prognosis. One limitation was the study's small size, its researchers noted. "While we consider our results ā€¦ very exciting and mechanistic, we acknowledge that the potential consideration of ceramide levels as biomarkers for disease progression in MS would require validation ... using larger cohorts with a longitudinal and/or cross-sectional design," they concluded. "It will also be important to evaluate the effectiveness of dietary intervention (with an emphasis on the reduction of specific classes of saturated fats), as potential modulator of plasma ceramide levels and possibly of disease course in MS patients."

Cleveland Clinic Neurologist Applauds Mayzent’s FDA Approval, But Surprised by Those It May Not Treat

When theĀ U.S. Food and Drug Administration approvedĀ the disease-modifying therapy Mayzent forĀ relapsing types of multiple sclerosis, itĀ specified in its label that the treatment was for people withĀ clinically isolated syndrome, relapsing-remitting MS, and ā€” importantly ā€”Ā secondary progressive MSĀ provided they have "active" disease. The approval is good news, an MS researcher and physician saidĀ toĀ Multiple Sclerosis News TodayĀ in an interview, but "surprising" in that the FDA's decision was largely based on a trial that didn't involve CIS patients and wasn't focused on responses among particular types of SPMS. ā€œIt's the first time that I've seen in the MSĀ field that regulatorsĀ made an approval designation ā€” activeĀ secondary progressive MS ā€” based on an underpowered subgroupĀ analysis,ā€ saidĀ Robert Fox, MD, a neurologist at the Mellen Center for Multiple Sclerosis at the Cleveland Clinic. Novartis'Ā medication, as a first oral therapy approved in the U.S. forĀ a form ofĀ SPMS,Ā is a big step forward in MS treatment, he said. But details of the FDA's decisionĀ caughtĀ him off guard. Fox served on the steering committee for the EXPAND Phase 3 clinical trial ,Ā on which the FDA decision was largely based.Ā His clinic was also one of the sites treating and evaluating patients in this pivotal study. Results of the EXPAND trial showed thatĀ Mayzent could reduce the risk of disability progression at three months (the trialā€™s primary endpoint, or goal) by 21% in treatedĀ SPMS patients, compared to those given aĀ placebo. Among those with active SPMS (meaning with relapses), a 33% reduction was observed. The treatment, an S1P modulator that works in part to keep lymphocytes from entering the brain to trigger inflammation,Ā alsoĀ decreased the annualized relapse rate by 55% and improved cognitive processing speed in all treated patients.Ā  ā€œWhat was found, and I think quite clearly found in a large-size study, was that siponimod in patients with secondary progressive MS clearly slowed the progression of clinical disability over the course of the trial,ā€ Fox said. ā€œIt's a statistical concept ā€” obviously patients either progress or they don't progress ā€” but on an overall basis there was a 21% slowing in the rate of progression of clinical disability.ā€ The FDAā€™s decision is particularly important for SPMS patients. While Ocrevus (ocrelizumab) alsoĀ treats all relapsing MS forms and people with primary progressive disease (PPMS), it's an intravenous therapy given every six months. Mavenclad (cladribine), approved for relapsing patients in the U.S. just days after Mayzent, is another oral and active disease therapy. To Fox, Mayzent seemed to reach beyond only those secondary progressive patients with clinically active disease. ā€œReally, this is the only drug that's been found to be effective in secondary progressive MS," he said. ā€œTo that degree, it stands alone.ā€ That's why two points in the FDA's decisionĀ surprised him. The firstĀ is the label's specific mention of clinically isolated syndrome. CISĀ is defined asĀ theĀ first clinical presentationĀ of this diseaseĀ ā€” aĀ neurological episode that lasts at least 24 hours, and is characterized by inflammatory demyelination (the loss of myelin, the protective coat surrounding neurons). Ā  For clinicians like Fox, CIS is a first manifestation of MS ā€” a kind of "mono sclerosis."Ā Since thereā€™s only one documented attack, it canā€™t yet be considered multiple sclerosis, ā€œas the multiple hasn't happened,ā€ Fox said, but many "in the field consider CIS to be ā€¦ an early stage of MS." ā€œIf the patient has a whole bunch of lesions on their brain [as seen on an MRI scan] and they had a single clinical event, ah, probably, they have MS,ā€ he said. Regulatory bodies like the FDA,Ā however,Ā have historically considered CIS to be its own separate entity. That makes this decision doubly surprising, according to Fox, since the EXPAND trial only enrolled patients with SPMS, not CIS. Ā  ā€œIt's the first time I've seen them approve for CIS specifically when there wasn't a trial in CIS,ā€Ā Fox said. ā€œI agree with it ā€” I don't have a problem with it ā€” it just surprised me that the regulators were so progressive in their appreciation of MS.ā€ The second ā€” and far more unsettling ā€” surpriseĀ wasĀ the FDAā€™s decision toĀ only approve Mayzent for ā€œactiveā€ SPMS patients, instead of all SPMS patients. This decision didnā€™t come out of nowhere, he noted, but it remains puzzling in the context of the EXPAND trial.Ā  InĀ compiling trial results, investigators did a subgroup analysis ā€” as they often do, almost as an aside for research reasons ā€” and found more favorableĀ responses to Mayzent treatmentĀ in patients with active inflammation beforeĀ the trial's start, those it determined to be with "active" disease. Ā  ā€œThere was a third of patients who had a relapse in the two years prior to enrollment, and those patients actually had a 30% slowing in disability progression, compared to the 21% overall,ā€ Fox said. This certainly does suggest that Mayzent can be more effective in people with active disease ā€” but there's a catch. The trial itself was not designed to make such a distinction. It enrolled SPMS patients regardless of activity, and its priority goal was changes in disease progression across all who were treated with Mayzent or given a placebo. Ā  ā€œWhat's important is that the trial was powered for the overall outcome. It was not powered for subgroup analysis,ā€ Fox said,Ā considering this a crucial point.Ā  In clinical studies, being ā€œpoweredā€ refers to theĀ enrollingĀ of whatever specific number of participants a study needs to ensureĀ itsĀ results will reach statistical significance. More people are redundant and, as such, an unnecessary cost; fewer could mean that trial's conclusions cannot be supported by rigorous scientific measures.Ā  In other words, Fox said, the only conclusions that can be drawn from the EXPAND study reliably ā€” with rigor ā€” are based on data drawn from all its SPMSĀ patients, not aĀ subgroup with active disease. This trial ā€œfollowed over 1,600 patients for the clinicalĀ disability. These are purposely powered so that you're not following twice as many people as you need toĀ ā€¦ you're powered for that primary outcome,ā€ he said. ā€œSo, how could they [the FDA] look at a subgroupĀ analysis and make an approval decision based on a subgroupĀ analysis that was underpowered?ā€ The neurologist gave as examplesĀ other subgroup differences found in trial analyses that didn't affect regulatory approval ā€” but to his mind, equally could have.Ā One was an analysis findingĀ female SPMS patients respondedĀ to the therapy better than males,Ā showing lesser disease progression. "So why didn't they just approve it for the females and not the males?" Fox asked. But, when asked, Fox did not think the labelĀ toĀ necessarily be an error. "My point is the absurdity of it," he said. "How could they make the regulatory approval based on a subgroupĀ analysis that wasn't powered for conclusions?" He was also particularly troubled becauseĀ the FDAĀ ā€œdidn't define what ā€˜activeā€™ means ā€”Ā is it just a relapse, or is it MRI disease activity?"Ā  For many clinicians, ā€œactiveā€ SPMS refers to ongoing inflammation that can be observed on MRI (magnetic resonance imaging) scans. In EXPAND, however, the active subgroup was defined as patients with clinical relapses within two years of being enrolled in the trial. Fox worries about this apparent lack of a regulatory definition of "active" SPMS, since ā€œobviously, the insurance companies are going to seize upon that, and they're going to look for every way they can to avoid covering it for patients.ā€ Mayzent, Fox agreed,Ā is likely to be expensive. The therapy is reported to carry a U.S. list price ofĀ $88,500 a year. ā€œI always have a concern about the cost of these drugs. They're all fearfully expensive,ā€ he said, noting he treats SPMS patients. His focus now is on working to ensure that possible regulatory and financial hurdles wonā€™t pose too much of an obstacle for patients, especially those with SPMS. ā€œI don't know what the insurance companies are going to do with this, but I'm hoping that it is available for my patients, and I say that as their clinician,ā€ Fox concluded.