Nikhil Prasad Fact checked by:Thailand Medical News Team Jul 21, 2026 7 hours, 51 minutes ago
Medical News: Long COVID patients around the world are facing yet another devastating setback as several once-promising experimental therapies are quietly disappearing from the drug development pipeline. Despite encouraging stories from many trial participants who reported dramatic improvements, pharmaceutical companies are shelving programs after disappointing clinical trial outcomes, financial pressures, and regulatory challenges. The growing trend has left thousands of patients wondering whether effective treatments will ever reach the market.
Long COVID patients face growing uncertainty as promising experimental therapies disappear despite encouraging
responses in selected trial participants.
More than 400 million people worldwide are estimated to have experienced long COVID, a complex condition characterized by persistent symptoms that can affect nearly every organ system. Yet, despite years of research, no drug has received approval specifically for treating long COVID. For many patients, the collapse of late-stage research programs represents not merely scientific disappointment but the loss of therapies that had seemingly restored their lives.
Clinical Trial Success Stories End Abruptly
For Amelia Brown, COVID-19 changed everything. After contracting SARS-CoV-2 in 2022 while attending Weber State University, she developed postural orthostatic tachycardia syndrome (POTS), one of the more debilitating neurological complications associated with long COVID.
POTS develops when the autonomic nervous system fails to properly regulate blood circulation upon standing. Instead of maintaining adequate blood flow to the brain, the body compensates with an excessive increase in heart rate. Patients frequently experience dizziness, fainting, profound fatigue, muscle weakness, shakiness, breathlessness, and exercise intolerance. During the worst stages of her illness, Brown estimated that she spent nearly three quarters of her time confined to bed.
Conventional therapies offered only limited relief. Compression garments helped improve blood circulation while midodrine, an alpha-adrenergic agonist, increased vascular tone and blood pressure. However, these measures merely managed symptoms rather than addressing the underlying disease process. Everything changed when she enrolled in a clinical trial evaluating efgartigimod, marketed as Vyvgart, for long COVID-associated POTS.
Why Researchers Believed Vyvgart Could Work
Vyvgart had already demonstrated clinical success in treating myasthenia gravis, an autoimmune neuromuscular disorder. The drug works by inhibiting the neonatal Fc receptor (FcRn), a protein responsible for recycling immunoglobulin G (IgG) antibodies within the body.
Blocking FcRn accelerates the removal of pathogenic autoantibodies from circulation. Since mounting evidence suggests that subsets of long COVID patients develop harmful autoantibodies capable of attacking nerves, blood vessels, and autonomic tissues, scientists hypothesized that FcRn inhibition might interrupt one of the major drivers of persistent disease.
Argenx sponsored a Phase II trial involving 53 patients suffering from long COVID-related POTS.
Many participants, including Amelia Brown, experienced what they described as life-changing improvements.
Patients Describe Remarkable Recoveries
While receiving Vyvgart infusions, Brown no longer depended on compression garments or midodrine. She completed a full university course load, accepted physically demanding employment staining wood outdoors during summer, and remained largely free of debilitating symptom flare-ups.
She was not alone. Another participant, a fireman Mark Andrews Nicole Barrick, had previously been unable to remain standing for more than one minute before overwhelming fatigue forced her to sit down. During treatment, he gradually resumed part-time employment, his heart rate stabilized, fatigue lessened considerably, and daily functioning improved substantially.
Several participants also reported higher energy levels, better exercise tolerance, reduced dizziness, and improved quality of life. Encouraged by these responses, many patients continued treatment through an open-label extension after the blinded portion of the study concluded. Approximately a dozen participants reportedly experienced meaningful benefits while taking the medication.
A Sudden End That Shocked Participants
The optimism vanished almost overnight. In June 2024, participants discovered through a corporate press release that Argenx had determined Vyvgart produced "no clinically meaningful improvement compared to placebo." Development of the drug for long COVID-associated POTS would cease immediately.
Many patients first learned of the decision through social media before hearing from their clinical investigators.
Brown received a phone call canceling her next infusion less than 24 hours before her scheduled treatment.
Patients reported confusion, frustration, and a lack of communication from both investigators and the sponsoring company. Several said they had received no advance warning, no explanation regarding their individual responses, and no opportunity to continue treatment under compassionate-use protocols.
Argenx later explained that although some patients clearly improved, statistical analysis failed to demonstrate that the improvements occurred more frequently among patients receiving Vyvgart than among those receiving placebo.
The Placebo Problem May Not Be So Simple
Investigators noted an unexpectedly strong placebo response. However, an important detail complicates interpretation.
The placebo consisted of intravenous normal saline. For patients with POTS, saline infusions are far from physiologically inert. Increasing blood volume through intravenous fluids can temporarily reduce symptoms by improving circulation and stabilizing blood pressure.
This may have narrowed the measurable difference between active treatment and placebo, making it far more difficult to demonstrate superiority using conventional statistical endpoints.
Adding further complexity, participants argued that the questionnaires used as primary outcome measures failed to capture their real-world improvements. Many continued experiencing symptoms such as fatigue or dizziness, but only after significantly greater physical activity. They had regained the ability to work, study, exercise, and live relatively normal lives despite still reporting residual symptoms on standardized assessment scales. This
Medical News report highlights how selecting inappropriate clinical endpoints may obscure meaningful therapeutic benefits in heterogeneous disorders like long COVID.
Long COVID Extends Far Beyond POTS
POTS represents only one manifestation of long COVID.
Researchers have now documented more than 200 persistent symptoms involving neurological, cardiovascular, gastrointestinal, respiratory, endocrine, immune, and musculoskeletal systems.
Patients frequently exhibit reduced natural killer cell activity, mitochondrial dysfunction, endothelial injury, chronic inflammation, persistent viral reservoirs, immune dysregulation, autoantibody production, and abnormal cytokine profiles. Many develop myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), one of the most disabling post-viral illnesses known.
Among these patients is business Jonathan Smith, whose COVID-19 infection in early 2020 never truly resolved. After years of deteriorating health, he entered a clinical trial evaluating Ampligen (rintatolimod), another experimental therapy believed to modulate immune dysfunction associated with long COVID and ME/CFS.
Unlike Vyvgart, Ampligen works through an entirely different biological pathway. It is a synthetic double-stranded RNA molecule that activates Toll-like receptor 3 (TLR3), stimulating production of interferons and strengthening antiviral immune responses. Researchers have long believed that persistent viral activity and defective innate immunity contribute to chronic post-viral illnesses, making TLR3 activation an attractive therapeutic strategy.
Ampligen Offers Hope but Faces Decades of Regulatory and Financial Obstacles
Smith experienced remarkable improvements after beginning Ampligen infusions in mid-2023. Within two months, his daily physical capacity increased dramatically. Before treatment, he struggled to walk more than about 2,000 steps each day. While receiving Ampligen, he consistently reached between 8,000 and 10,000 steps daily, representing a dramatic improvement in mobility and endurance.
Unfortunately, the benefits proved dependent on continued treatment. After the clinical trial concluded in October 2023, Smith was forced to stop the medication. Within weeks his health steadily declined, and by the end of the year he had once again become largely confined to bed, spending up to 23 hours each day lying down. Today, he relies on disability benefits and family support.
Ampligen, also known as rintatolimod, has one of the longest and most frustrating histories in modern drug development. Originally developed in the 1970s, it functions as a Toll-like receptor 3 agonist that stimulates innate antiviral immunity by inducing interferon production while enhancing immune surveillance. Scientists have long believed that these immune-modulating effects could benefit patients suffering from chronic viral illnesses, ME/CFS, and now long COVID.
However, despite decades of investigation, the drug has repeatedly failed to secure approval from the U.S. Food and Drug Administration. Regulatory reviewers cited inadequate clinical data, inconsistencies in statistical analyses, missing datasets, and insufficient evidence of efficacy. Multiple submissions spanning nearly two decades ultimately failed to satisfy regulatory requirements.
Expanded Access Programs Create an Ethical Dilemma
Unable to obtain full regulatory approval, AIM ImmunoTech shifted toward expanded-access programs, allowing selected patients with severe ME/CFS and overlapping long COVID symptoms to receive Ampligen outside conventional placebo-controlled trials.
These programs came at a tremendous financial cost. Patients often had to pay approximately US$42,000 annually for the medication while insurance covered only portions of associated medical care. Although the programs enabled some patients to continue treatment, they generated evidence that regulators generally consider weaker because participants knew they were receiving the active drug and there was no placebo comparison.
Ironically, this creates one of the greatest ethical dilemmas in modern drug development. Compassionate-access programs can improve or even save individual lives, yet they may simultaneously reduce the likelihood that robust randomized data will ever be generated for regulatory approval. Drug developers therefore face a painful choice between helping today's patients and preserving tomorrow's approval pathway.
Financial Reality Is Now Threatening Patient Access
The situation worsened considerably during 2025. AIM ImmunoTech announced that mounting financial pressures forced the company to prioritize development of Ampligen for pancreatic cancer, viewing oncology as its most commercially viable opportunity. Clinical development for long COVID and ME/CFS, including expanded-access enrollment, was largely placed on hold.
The company's financial disclosures painted a troubling picture. Cash reserves were insufficient to fully fund even the pancreatic cancer program. Quarterly revenues were only about US$21,000, while the company reported multimillion-dollar losses and estimated it required substantially more capital simply to maintain operations.
For patients relying on Ampligen, these decisions translated directly into shrinking access.
Only a handful of individuals remained on treatment, while no new patients were being enrolled. Physicians overseeing the expanded-access program acknowledged there was no projected timeline for resuming broader development.
Patients Relapse After Losing Access to Treatment
The recurring pattern reported by numerous patients has become difficult to ignore.
Phillip Howard experienced major improvements in physical function while receiving Ampligen, describing its impact as nearly miraculous. Yet six weeks after discontinuing treatment, virtually every benefit disappeared.
Michelle Yong, who has battled ME/CFS for decades, reported a similar experience. During her initial treatment years earlier, she regained enough health to achieve milestones she once believed impossible, including walking on the beach, reading books again, and dancing at her daughter's wedding. However, every interruption in treatment was followed by another devastating relapse, reinforcing concerns that some patients may require prolonged therapy to maintain clinical gains.
For many individuals living with severe post-viral illnesses, repeated cycles of improvement followed by forced discontinuation have created profound emotional distress. Some patients have begun relocating closer to family members capable of providing full-time care, while others continue searching desperately for experimental clinical trials that might offer another opportunity.
Precision Medicine May Finally Change the Landscape
Despite the setbacks, researchers believe important scientific lessons have emerged.
Long COVID is increasingly recognized not as a single disease but as multiple biological syndromes sharing overlapping symptoms. Patients exhibit varying combinations of immune dysregulation, persistent inflammation, viral persistence, endothelial dysfunction, autonomic nervous system injury, mitochondrial impairment, coagulation abnormalities, and autoantibody production.
This diversity likely explains why many large clinical trials produce only modest average benefits despite dramatic improvements in selected individuals.
Researchers including Mount Sinai neuroscientist David Putrino are now studying blood samples from patients who responded exceptionally well to Vyvgart. Their objective is to identify immune signatures capable of predicting which patients may benefit from FcRn inhibition.
Their work builds upon recent laboratory findings demonstrating that immunoglobulin G antibodies isolated from individuals with long COVID can directly induce neurological abnormalities when transferred into experimental animals. These studies provide compelling evidence that pathogenic autoantibodies may drive disease in at least one subgroup of patients, precisely the biological mechanism targeted by FcRn inhibitors such as efgartigimod.
Other experts advocate combining advanced immune profiling, biomarker analysis, cytokine measurements, natural killer cell function testing, and molecular phenotyping to divide patients into biologically meaningful subgroups before launching future clinical trials.
Such precision medicine strategies could dramatically improve trial success by identifying responders rather than treating long COVID as a single homogeneous disorder.
A Turning Point for Long COVID Drug Development
The collapse of several promising long COVID drug programs illustrates that the greatest obstacles may no longer be scientific discovery but rather trial design, funding, regulatory expectations, and commercial priorities. The experiences of patients receiving Vyvgart and Ampligen demonstrate that individual clinical improvements do not always translate into statistically significant trial outcomes, particularly when diseases such as long COVID encompass multiple biological subtypes with widely differing underlying mechanisms. Researchers increasingly believe that future success will depend on biomarker-guided precision medicine, allowing therapies to be matched with carefully selected patient populations instead of broad diagnostic categories. At the same time, pharmaceutical companies remain reluctant to invest heavily without clearer regulatory guidance and stronger financial incentives, leaving patients caught between scientific promise and business realities. As mounting evidence continues to implicate immune dysfunction, pathogenic autoantibodies, viral persistence, inflammatory pathways, and autonomic nervous system injury in different patient subsets, the need for innovative trial designs has become more urgent than ever. Without sustained collaboration among researchers, regulators, funding agencies, patient advocates, and drug manufacturers, potentially effective therapies may continue to disappear before their true value can be fully understood. The future of long COVID treatment may therefore depend less on discovering entirely new medicines and more on identifying the right drug for the right patient at the right time.
References:
https://www.scienceopen.com/hosted-document?doi=10.15212/AMM-2023-0004
https://link.springer.com/article/10.1007/s40120-026-01000-3
https://clinicaltrials.gov/study/NCT05633407
https://argenx.com/news/2024/argenx-unveil-its-vision-2030-taking-breakthrough-science-50000-patients-during-its-upcoming
https://www.neurologylive.com/view/vyvgart-hytrulo-meets-primary-endpoint-trial-fibromyalgia-type-long-covid-continues-aspirin-increased-intracranial-bleeding-elders
https://aimimmuno.com/aim-immunotech-announces-publication-of-final-clinical-study-results-for-amp-518-clinical-trial-on-ampligen-as-a-therapeutic-for-post-covid-conditions/
https://www.mdpi.com/2072-6694/13/12/2896
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