The Food and Drug Administration on Tuesday approved a decades-old prescription vitamin called leucovorin as the first treatment for a rare genetic disorder in certain adults and children. 

The move comes months after the Trump administration touted leucovorin as a potential therapy for a broader group of patients with autism spectrum disorder symptoms. The claim sparked skepticism among some in the medical and research community, but fueled excitement among families, spiking prescriptions of the drug in the U.S. 

One FDA official told reporters Monday that “we don’t have sufficient data to say that we could establish efficacy for autism more broadly” but said the agency is open to interest from companies in studying leucovorin in the autism population. 

The medication, also referred to as folinic acid, is a synthetic form of vitamin B9 that has been used to treat the toxic side effects of chemotherapy. Just a handful of small trials have suggested that leucovorin could be effective as an off-label treatment for children with autism, and some families have reported that it helped their nonverbal kids develop more language and social skills.

FDA officials, who requested anonymity to discuss the decision, told reporters Monday that they started with a broad review of leucovorin as an autism treatment before narrowing its approval to a smaller population with cerebral folate deficiency, a rare genetic mutation that prevents folate – a key vitamin – from properly reaching the brain. 

The condition shares overlapping features with autism, typically develops in young children under age 2 and can cause severe developmental delays, seizures, a lack of muscle control and other serious neurological complications. 

The officials said the FDA found that using leucovorin in patients with that condition produced the “highest quality data” to support an expanded approval, which will apply to both generic versions of the drug and GSK’s old branded medication, Wellcovorin. 

“That was the data where we saw the largest effect sizes,” one FDA official said on the call. “So we narrowed in on that population, just because we felt like that was the strongest both scientific rationale and also the largest treatment effects that could be used to then overcome some of the limitations in the data sources.”

The approval was based on a systematic review of published literature on the area, including patient case reports, but not a randomized controlled clinical trial. The same official acknowledged there can be biases with systematic reviews, but emphasized that the treatment effects were so large that they outweighed those concerns. 

The FDA is encouraging existing manufacturers of leucovorin to increase production to match higher demand for the drug, the officials added. While GSK originally marketed the drug from 1983 until 1997, the company said in September that it has no plans to relaunch and manufacture the product itself.

In a release Tuesday, Dr. Tracy Beth Hoeg, acting director of the FDA’s Center for Drug Evaluation and Research, said the approval demonstrates the FDA’s commitment to “rapidly identifying effective treatments for ultra rare diseases while maintaining the same evidentiary standards for approval.”

When prestige hair care brand Olaplex first debuted on the Nasdaq in late 2021, it surpassed pricing predictions and gained momentum fast.

The company opened at $25 per share, an increase from its initial public offering pricing estimates. It was part of a broader group of retailers that went public that year amid an IPO boom. Olaplex hit its all-time high just a few months after its public debut, reaching a price of $29.41 on Jan. 3, 2022.

But that run didn’t last long.

Since its IPO, Olaplex’s stock performance has plunged drastically, losing nearly 95% of its value. The S&P 500, meanwhile, has gained more than 50% over the same period. Now, the company is hoping to turn its performance around.

“We are encouraged by the momentum we are seeing as we work to build a business that lives up to our breakthrough science, and we look forward to the journey ahead,” CEO Amanda Baldwin told CNBC in an exclusive statement.

Olaplex declined to comment to CNBC beyond that statement.

The company has a range of products, sold directly to consumers and to professional salons, that use a bond-building technology to strengthen and restore hair.

Its stock began sinking due to weakened demand and regulatory challenges in 2022, but some of Olaplex’s main issues were borne out of an early 2023 lawsuit filed against the company that accused the brand of using harmful ingredients. It involved nearly 30 women who alleged that the products caused hair loss and hair damage, citing an ingredient called lilial.

The company aggressively denied those claims and said it had removed the lilial ingredient from all of its products, but consumers on social media continued to attack the brand, its formulations and the alleged side effects.

Though the case was dismissed later that year, the allegations left lasting damage on the brand’s reputation. Over the course of that year, its stock sank more than 50% – and it never recovered. Shares of Olaplex are now trading at less than $1.50, with a market cap of roughly $1 billion.

In fiscal year 2023, Olaplex said its net sales decreased 47.8% in the U.S. compared with the previous year, while its net income sank 74.8%.

In the meantime, the hair care industry added new players that fought for Olaplex’s falling market share. Companies like K18, Ouai and Redken have crowded the playing field, gaining popularity while Olaplex battled social media backlash.

In late 2023, Olaplex recruited Baldwin, the former CEO of beauty brand Supergoop, to helm the company and turn around its brand strategy.

At the time, Baldwin said she saw “tremendous opportunity” to help the brand by deepening engagement with its customer base, innovating new products and sharpening its press strategy.

“Olaplex stands apart as a category creator redefining what is possible through the combination of beauty and science,” Baldwin said in a statement in late 2023.

Late last month, the company launched a new product, a pre-shampoo treatment intended to revitalize hair that marked the company’s next foray into advancing its bond-building technology.

In its fourth-quarter earnings report last week, Olaplex reported a 4.3% increase in net sales compared with the fourth quarter of 2024, to $105.1 million. But for the full 2025 fiscal year, net sales increased just 0.1%. Shares of the company sank more than 20% after the report.

Athletic apparel maker Fabletics is launching its first denim collection, signaling the once hot athleisure category is starting to slow down, the company announced Tuesday. 

The collection, launching online and in select stores on Thursday, will include 11 styles and seven washes across both women’s and men’s. Items will be priced between $79.95 and $174.95, depending on whether shoppers are members of Fabletics’ subscription program. 

“We’ve had over a million of our customers tell us that if Fabletics offered denim, they’d be highly interested in it, and that’s really what got us started on our journey of expanding into the denim category,” Fabletics co-founder and CEO Adam Goldenberg told CNBC in an interview. “We do believe denim is on an upswing. We’ve seen that, you know, we started [looking into denim] over two years ago, so it’s the right time.” 

Fabletics, which earned more than $1 billion in revenue last year, is expanding into denim as consumer preferences change. The “soft” type of dressing that became popular during the pandemic, featuring comfortable joggers, sports bras and hoodies, has fallen out of favor with some shoppers.

Instead, as hybrid work begins to fade, many consumers are choosing to dress back up again and are opting for denim over leggings as the casual staple that works both on the weekends and at the office. 

While the athleisure market is still expanding, that rate of growth has wobbled in North America, data from market intelligence company Euromonitor International show. 

The sports apparel market is projected to grow 2.3% in North America in 2026 from 2025, down from 3.1% between 2023 and 2024. Meanwhile, the denim market is expected to grow 2.1% this year, up from 0.7% between 2023 and 2024. 

Globally, the athleisure market grew 2% last year while the denim market grew 4%, according to separate figures from GlobalData. 

“What we found coming out of the pandemic is like, comforts become king,” said Goldenberg. “So even now, as consumers are, I would say, dressing up more they’re still wanting to do it in a way that feels good and is more comfortable, right? And we heard that very loudly from our customers when we were developing denim.”

The U.S. has fallen in and out of love with denim for decades, which has plagued fashion and led major apparel companies like Levi Strauss, American Eagle and Gap to structure their businesses so they’re not as exposed to changing styles. Each company is a market leader in denim, but they also have their own athleisure brands, which shields them from shifts in fashion. 

Changing trends have proven more difficult for niche players like Lululemon, which boomed during the pandemic and is now falling behind as denim reigns supreme again. 

Lululemon has worked for several years to expand outside of its core yoga pant assortment into more lifestyle categories, including outerwear, T-shirts and made for work trousers, as fashion preferences shifted. The move has allowed Lululemon to increase its total addressable market, but some critics have said it’s alienated Lululemon’s core customers and contributed to a slowdown in growth in the retailer’s core Americas market. 

Nike‘s former CEO John Donahoe grew the retailer into a roughly $50 billion brand by focusing on lifestyle and streetwear styles. While the strategy briefly led to growth, it ultimately contributed to a decline in market share because it distracted the company from its core, performance assortment. Now, Nike’s new CEO Elliott Hill is working to refocus the brand on sports to win back that core, athlete consumer. 

Goldenberg disagreed that Lululemon’s challenges came from expanding into new categories and instead said Fabletics, along with up and coming private athleisure brands Alo Yoga and Vuori, are taking market share from incumbents. He also said Fabletics’ expansion isn’t coming at the expense of innovation in its core athleisure products, either. 

“All these category expansions need to be ‘and’ and not ‘and or’ right?” said Goldenberg. “So we need to be doubling and tripling down on our innovation and activewear while we make sure that we’re launching denim in a way that, like, is truly the best product out there.” 

He added that Fabletics has already proven it can successfully scale into new categories, which has helped the company get ahead of schedule two years into its five-year plan of doubling revenue and quadrupling profits. In 2020, it launched a men’s category, which is now more than a $300 million business, and its scrubs line, which has grown to $75 million in a little over two years.

Goldenberg said activewear is still Fabletics’ main priority, but category expansion will be critical in winning more sales from its current customers and acquiring new shoppers. 

“I’ll give you scrubs as an example,” said Goldenberg. “We’re now bringing in thousands of new customers a month into the Fabletics family through them. First purchasing scrubs, but within 90 days, well over 50% of them have also purchased activewear.”