Novartis's Zolgensma (onasemnogene abeparvovec)
The $2.1 million gene therapy, a data manipulation scandal and the price of a cure
Zolgensma is a one-time gene therapy for spinal muscular atrophy (SMA), the leading genetic cause of death in infants. It can transform the lives of affected children. It is also the subject of two separate controversies: a record-breaking price that set the benchmark for gene therapies, and the revelation that data submitted to the FDA had been manipulated, a fact the developer knew before approval but disclosed only afterwards.
Questions
What is Zolgensma and why is it considered a breakthrough?
A single-infusion gene therapy approved in 2019 for children under 2 with spinal muscular atrophy — transforming outcomes for a disease that killed most patients by age 2 — developed by AveXis, which Novartis bought for $8.7 billion in 2018.
SMA is caused by mutations in the SMN1 gene, leading to the loss of motor neurons and progressive muscle weakness. In its most severe form, Type 1, children typically die by age 2 without treatment. Zolgensma delivers a working copy of the gene using an adeno-associated virus vector in a single infusion. The FDA approved it on May 24, 2019 for children under 2 with SMA. ICER's president said Zolgensma was "dramatically transforming the lives of families" affected by the disease, and at two years of follow-up, no treated patients in early studies had shown deterioration in motor function. The therapy was developed by AveXis, which Novartis bought in April 2018 for $8.7 billion. Its clinical value is not in serious dispute; its price and the integrity of its regulatory submission are.
Q2How was Zolgensma's $2.125 million price set?
Novartis assembled academics and consultants to justify a value-based price against Spinraza; executives floated $4–5 million before launch; and ICER's founder described investor pressure to set a high price to establish a gene-therapy precedent.
Novartis set a list price of $2.125 million, making Zolgensma the first US drug over $1 million and the world's most expensive medicine at the time. ProPublica reported that Novartis assembled academics and consultants to develop a value-based case, comparing Zolgensma with Biogen's SMA drug Spinraza, which costs about $750,000 in its first year. One co-authored study concluded the therapy would be cost-effective at up to $5 million, and executives had publicly floated $4 million to $5 million. ICER's founder described pressure from Wall Street, saying investors wanted a high price to set a precedent. Novartis presented the final figure as half the cost of ten years of Spinraza, and offered payers the option of annual instalments of $425,000 over five years and outcomes-based agreements.
Q3Did ICER think Zolgensma's price was justified?
ICER first said it needed to be under $900,000; on approval day it revised upwards to $1.2–2.1 million under generous assumptions — but critics argued Novartis's benchmark was Spinraza, itself priced at more than seven times standard cost-effectiveness thresholds.
ICER's view changed. Its final April 2019 report concluded Zolgensma would need to be priced under $900,000 to be cost-effective. On approval day, after considering new data in pre-symptomatic infants and assuming long-lasting benefit and routine newborn screening, ICER updated its range to $1.2 million to $2.1 million per life-year-gained benchmark, and said the price fell within the upper bound of that range. Critics in Health Affairs argued the price was still poorly justified, noting that Novartis's comparison with Spinraza inflated its value because Spinraza itself cost $1.1 million per quality-adjusted life year gained, more than seven times standard thresholds. If Spinraza were fairly priced, they argued, its ten-year cost would be about 30% of Zolgensma's price.
Q4What publicly funded research went into Zolgensma?
The NIH invested more than $450 million in SMA-related science and parent-led charities funded early research at Nationwide Children's Hospital — with no conditions protecting public interests or linking price to that investment when AveXis commercialised the product.
ProPublica reported that the NIH invested more than $450 million in SMA-related science, and that a parent-led charity raised about $2 million for early research at Nationwide Children's Hospital that underpinned the therapy. When AveXis commercialised the product, there were no conditions protecting the charities' financial interests or linking the price to public investment. Novartis also received a pediatric priority review voucher, a government incentive that can be sold for around $100 million or used to speed review of another drug. Critics argue that when the public funds a large share of the underlying science, and the company receives valuable regulatory incentives, the resulting price should reflect that shared investment. Novartis argues that commercial development, manufacturing and clinical trials required billions in private capital and risk.
Q5What data was manipulated in Zolgensma's application?
Animal-testing data used to demonstrate comparability between an early and final manufacturing process was manipulated — a small portion of the BLA not affecting human trial data, but disclosed to the FDA only on June 28, more than a month after the May 24 approval.
The manipulated data came from product testing in animals, used to show that an early version of Zolgensma was comparable to the later version made through a different manufacturing process. On August 6, 2019 the FDA disclosed that AveXis had informed it on June 28, more than a month after approval, about a data manipulation issue affecting the accuracy of certain data in the biologics licence application. The FDA said its concerns were limited to a small portion of the product testing data and did not change its positive view of the human clinical trials. The manipulated test was no longer in use and did not affect the approved product. The FDA kept Zolgensma on the market while it investigated.
Q6When did Novartis know about the manipulated data?
AveXis personnel were aware of potential manipulation dating back to January 2018, learned of the specific problem on March 14, 2019 but waited until after the May 24 approval to open a formal inquiry — disclosing to the FDA on June 28, the gap at the heart of the controversy.
This is the heart of the controversy. The FDA said AveXis became aware of the issue before approval but did not tell the agency until afterwards. According to a Wall Street Journal report summarised by MedCity News, the company learned of the problem on March 14, 2019 but did not open a formal inquiry until May 15, and approval followed on May 24. A review of an FDA inspection report found AveXis personnel had been aware of potential data manipulation dating back to January 2018, with multiple instances observed by inspectors. Novartis CEO Vas Narasimhan said the company waited for the results of its internal investigation to provide the best information, not to secure approval first, and that scientists involved were being removed.
Q7How did regulators and lawmakers respond?
The FDA said it would likely have delayed approval and could pursue civil or criminal penalties; five senators called it "unconscionable"; and former Commissioner Gottlieb wrote he suspected there would be "wrongdoers here. And consequences."
The FDA said it would likely have delayed approval had it known, and that it would use its full authorities, including possible civil or criminal penalties. Former FDA Commissioner Scott Gottlieb wrote that he suspected there would be "wrongdoers here. And consequences." Five Democratic senators, including Bernie Sanders and Elizabeth Warren, urged the FDA to hold AveXis accountable, calling it "unconscionable" for a company to provide manipulated data to rush a product to market. AveXis was also required to submit BLA supplements for FDA review. Novartis pledged greater openness about data integrity. Details of any final penalty were not prominent in the public record reviewed for this article.
Q8Has Zolgensma had safety issues since approval?
Yes — in August 2022 Novartis reported the first two deaths from acute liver failure after more than 2,300 treatments, prefiguring the broader AAV liver-toxicity concerns that later emerged with Sarepta's Elevidys.
Yes. Acute liver injury was a known risk on the label, which is why patients receive steroids around the infusion. In August 2022 Novartis reported the first two deaths from acute liver failure, in patients in Russia and Kazakhstan, occurring five to six weeks after infusion and after steroid tapering. Novartis said it would add the deaths to the label and that the therapy's benefit-risk remained favourable after more than 2,300 treatments. European regulators subsequently considered new liver monitoring guidance. These risks are shared by other AAV gene therapies, as Sarepta's Elevidys later showed. For families, the risks are weighed against a disease that is often fatal without treatment.
Q9How have other health systems handled Zolgensma's cost?
England's NHS reached a confidential 2021 deal for eligible infants; US insurers accepted instalment and outcomes-based arrangements; but ICER's president acknowledged they "were going to cover Zolgensma no matter the price" — illustrating payers' limited leverage with curative therapies.
Outside the US, health systems have generally negotiated confidential arrangements. In March 2021 England's NHS reached a confidential agreement with Novartis to provide Zolgensma to eligible infants with Type 1 SMA. In the US, Novartis worked with insurers such as Cigna on instalment payments and outcomes-based agreements, under which it would refund part of the cost if treatment failed. Health Affairs critics noted that the instalment plan still ensured Novartis would be fully paid within five years, while the long-term durability of benefit was unknown. ICER's president acknowledged that insurers "were going to cover Zolgensma no matter the price", which illustrates how little leverage payers have with one-time curative therapies.
Q10How does Zolgensma compare with Spinraza?
Novartis framed Zolgensma as cheaper than ten years of Spinraza at $4.25M — but ICER put Spinraza's lifetime cost at $2.4M, not $4.25M, meaning at a fair price ten years of Spinraza would cost roughly 30% of Zolgensma: using an overpriced rival as a benchmark entrenches high prices across the disease area.
Spinraza (nusinersen), sold by Biogen, was the first SMA treatment and must be given repeatedly by injection into the spinal fluid. Novartis argued Zolgensma's one-time price was about half the cost of ten years of Spinraza, which costs about $750,000 in the first year. Critics said this comparison flattered Zolgensma. ICER calculated Spinraza's price equated to $1.1 million per quality-adjusted life year gained, more than seven times the highest accepted threshold, and put Spinraza's lifetime cost at $2.4 million rather than the $4.25 million implied by Novartis's framing. At a fair price, ICER said ten years of Spinraza would cost $648,000, about 30% of Zolgensma's price. A later commentary noted that when the comparator is set at $4 million over a decade, almost anything looks like a deal. Using an overpriced rival as a benchmark can therefore entrench high prices across a disease area.
Q11What is Zolgensma's legacy in the drug pricing debate?
Zolgensma set the gene-therapy price reference point — Elevidys later launched at $3.2 million — while its data manipulation episode raised questions about self-reporting reliability, demonstrating both the promise of one-time curative therapies and the unresolved problems of paying for and validating them.
Zolgensma set the reference point for gene therapy pricing. As Health Affairs warned, once one drug sets the price level in a category, future drugs tend to be priced in the same range or higher; Sarepta's Elevidys later launched at $3.2 million. The data manipulation episode also raised questions about whether regulators can rely on sponsors' self-reporting, particularly under pressure to approve therapies for fatal diseases quickly. On the other hand, the therapy's clinical benefit has been substantial, and ICER ultimately judged its price within a defensible range under generous assumptions. The Zolgensma case therefore demonstrates both the promise of gene therapy and the unresolved problems of how society pays for one-time treatments, and how it ensures the data behind them are sound.