Skyhawk Therapeutics, Inc.

iStock, wildpixel The FDA plans to hold an advisory committee meeting to discuss Capricor Therapeutics’ application for deramiocel, which the agency rejected last July. The news surprised CEO Linda Marbán, who told BioSpace the FDA has not communicated any issues of concern with the company’s resubmitted application. Linda Marbán was “surprised” when the FDA informed Capricor Therapeutics it would be holding an advisory committee meeting for its Duchenne muscular dystrophy cardiomyopathy cell therapy prior to its August target action date. “We really thought that it’s a very clean data set,” the CEO told BioSpace from Orlando, where Capricor is presenting five-year data from the ongoing open-label extension study of deramiocel at the Parent Project Muscular Dystrophy (PPMD) conference. “We have not gotten any issues that they want to discuss.” Marbán did offer a couple of possible theories for the adcomm—which comes after deramiocel aced a pivotal Phase 3 trial last December. “We did hear that [acting FDA Commissioner] Kyle Diamantas . . . said he wanted more adcomms, and so we’re kind of wondering if this is sort of in response to that,” she said. Indeed, Capricor was not the only recently rebuffed biotech on Friday to announce an advisory committee meeting for its new submission. Replimune revealed that the FDA plans to schedule an adcomm for its twice-rejected advanced melanoma therapy RP1 prior to an Aug. 2 decision date. Cancer Replimune gets early August decision date for twice-rejected melanoma drug Replimune’s resubmission for RP1 for melanoma comes after the departures of FDA leaders in place at the time of the drug’s first two rejections. The FDA expects to hold an advisory committee meeting in late July. June 26, 2026 · 3 min read · Tristan Manalac Read more Another possible reason, Marbán posited, is the recent regulatory friction in the Duchenne muscular dystrophy (DMD) space more broadly. Patients and families were thrown for a loop last year when the FDA temporarily requested that Sarepta Therapeutics halt shipments of its gene therapy Elevidys following the deaths of two nonambulatory patients with DMD. Sarepta initially stood its ground, refusing to stop all shipments of Elevidys, but ultimately complied. Just a week later, however, the FDA recommended that the voluntary hold be lifted for patients with DMD who are able to walk. “There’s been so many issues around Duchenne and treatment for Duchenne and Sarepta, maybe they’re being extra careful,” Marbán said of the FDA. Capricor would be forgiven having a sense of déjà vu. Deramiocel was rejected by the regulator in July 2025 after then–Center for Biologics Evaluation and Research (CBER) director Vinay Prasad canceled a scheduled adcomm—unilaterally, according to reporting by STAT News . In its complete response letter (CRL), the FDA said the data supporting deramiocel fell short of the “statutory requirement for substantial evidence of effectiveness.” Marbán was blindsided by the adcomm’s cancelation, which came in June 2025. The meeting, which had been scheduled for July 30, was listed on the Federal Register—and then, ten minutes later, it wasn’t. “Investors watch these boards all day, every day, so my phone started blowing up with ‘Your adcomm has been canceled. It’s been taken down. Why?’ I had no answers to give,” Marbán told BioSpace last August. “I couldn’t make an official statement.” In December 2025, Capricor’s fortunes began to look up when deramiocel hit both the primary and secondary endpoints in a pivotal trial. In the Phase 3 HOPE-3 trial, the cell therapy showed statistically significant benefits in upper-limb function, the study’s primary endpoint. It also slowed decline in cardiac function as measured by left ventricular ejection fraction, satisfying the key secondary endpoint. In March, the FDA accepted a resubmission for deramiocel and set a target action date of Aug. 22. FDA ‘Unprecedented’ FDA Leaks Sow Confusion for Patients, Sarepta and Capricor Sarepta and Capricor learned of key regulatory decisions from the media and investors, and Duchenne muscular dystrophy families have turned to the news for answers. Meanwhile, the FDA insists it remains committed to notifying companies of any regulatory action before sharing information with the media or public. August 4, 2025 · 7 min read · Heather McKenzie Read more A return to FDA normalcy? With the successful Phase 3 results, Capricor may not be a perfect fit with the FDA’s recent trend of providing second chances to rare disease drug applications previously rejected or refused by the agency. But that’s not to say deramiocel won’t benefit from the FDA’s seemingly adjusted stance toward external controls. In the past year, uniQure and REGENXBIO have had their gene therapy applications either discouraged or rejected, due in part to the use of externally controlled studies. Recently, however, the FDA has cleared uniQure to approval of AMT-130 for Huntington’s disease, and REGENXBIO to resubmit its application for its Hunter syndrome therapy, based on these very data. The use of an externally controlled study was “one of the major issues” raised in Capricor’s July 2025 CRL, Marbán said during a BioSpace webinar earlier this year. At the BIO International Convention in San Diego this week, former regulators cited the agency’s new investigational new drug pilot program as a sign that the FDA is returning to a state of normalcy. A return to adcomms could be another sign of this phenomenon. On April 30, the agency ended a 9-month advisory committee drought when the Oncologic Drugs Advisory Committee met to discuss two cancer drug applications from AstraZeneca. Then, last week, Moderna’s mRNA-based flu vaccine—which drew considerable industry skepticism when the FDA refused in February to even review the company’s application— won unanimous support from the agency’s advisory panel for vaccines. While these and other recent regulatory reversals following the May departure of former Commissioner Marty Makary have hinted at significant change at the FDA, Marbán is not convinced. “I think everybody thought that we had Prasad leave and Makary leave, that it was going to be a clean house at FDA, and as a result of a clean house, everything was going to get better again,” she said. “I personally am not convinced of that at all.” At CBER at least, Marbán said she believes the reviewers were “really clouded . . . by the Prasad etiology.” But the CEO was clear that she is not concerned about deramiocel’s chances of approval. While Capricor does not have a list of questions the FDA plans to discuss at the July adcomm, “We have the best key opinion leaders in the space that are going to be lined up to be presenting with us,” Marbán said, in addition to quality-of-life specialists and statisticians from around the globe. “We have a randomized double blind placebo control trial. We hit the primary endpoint, we hit the secondary endpoints,” Marbán said. “I don’t know what their issues would be.” FDA FDA’s uniQure, REGENXBIO reversals could bolster other near-term rare disease applications The FDA’s recently altered outlook on the evidence required for approval of rare disease drugs could have immediate benefits for companies including Skyhawk Therapeutics, Capricor Therapeutics and Biohaven. June 25, 2026 · 6 min read · Heather McKenzie Read more

iStock, klyaksun The FDA’s recently altered outlook on the evidence required for approval of rare disease drugs could have immediate benefits for companies including Skyhawk Therapeutics, Capricor Therapeutics and Biohaven. When the FDA cleared uniQure and REGENXBIO to file, or refile, for approval of their respective gene therapies based on current data, the agency put its recent regulatory guidance surrounding external controls into practice—potentially lifting the hopes of other near-term regulatory hopefuls. Last week, in what Convey Bio founder Benjamin McLeod in a LinkedIn post called possibly “the biggest CGT story of the year so far,” the FDA reversed the decision made under ex-commissioner Marty Makary to require a sham-controlled Phase 3 trial before it would consider uniQure’s AMT-130 for approval. Notably, that requirement was also a reversal of previous guidance given to uniQure by the agency that data from the company’s Phase 1/2 trial could be used as the primary basis for a biologics license application (BLA). “I think the FDA is making a lot of really smart decisions,” Bill Haney, CEO of Skyhawk Therapeutics, which is also developing a treatment for Huntington’s, told BioSpace . For Peter Pitts, a former associate commissioner at the FDA and president and co-founder of the Center for Medicine in the Public Interest, the FDA’s new direction can be attributed to the exit of Center for Biologics Evaluation and Research (CBER) Director Vinay Prasad at the end of April. “I think 2026 is divided into two pieces with a very specific reason, and that reason is the departure of Vinay Prasad,” Pitts told BioSpace . “I think with Dr. Prasad’s departure, FDA has returned to its senses as being a partner in innovation rather than a critic of innovation.” On Monday, the FDA further leaned into this new position, acknowledging that existing clinical data supporting REGENXBIO’s recently rejected Hunter syndrome therapy could support an accelerated approval application and that no further studies will be required, according to the biotech’s release . These latest moves also suggest new alignment with recent FDA guidance that cell and gene therapy developers should leverage innovative clinical trial designs , including those involving external controls such as historical or real-world data. UniQure’s pivotal Phase 1/2 trial—which returned positive three-year data in September 2025—compared the clinical outcomes for 24 patients given AMT-130 to those of propensity score-matched external controls from the Enroll-HD natural history data set. The biotech had been set to apply for FDA approval in the first quarter of this year until the FDA issued its surprise decision that a sham-controlled study would be required. Meanwhile, RGX-121 was turned away by the FDA in February, with the agency citing “uncertainty” over the eligibility criteria used in its registrational study and the biotech’s use of external controls, which it said “lack the comparability” with trial participants. The FDA recommended the company use “an appropriate untreated control.” The FDA’s new allowance of externally controlled studies to stand for uniQure’s BLA and REGENXBIO’s resubmission could also lift other late-stage development programs that have used such innovative study designs, as well as the industry more broadly. “I think it’s going to help every biotech,” Pitts said of the agency’s new approach. Here, BioSpace takes a closer look at four companies—Skyhawk, Capricor Therapeutics, Biohaven and Stoke Therapeutics—that may be among the first to see their luck turn. FDA FDA Reversals in Rare Disease Space Highlight Confusion Around External Controls While recent FDA guidance speaks to the agency’s support of innovative trial designs—including the use of external controls—the application of this flexibility appears to be inconsistent. One former regulator says the situation is more nuanced. April 6, 2026 · 6 min read · Heather McKenzie Read more Another feather in Capricor Therapeutics’ deramiocel cap Capricor Therapeutics’ investigational cell therapy deramiocel aced a pivotal Phase 3 trial in Duchenne muscular dystrophy–associated cardiomyopathy last December, setting the stage for an August decision . Prior to this triumphant turn, however, Capricor had been through the regulatory wringer with deramiocel. The company’s first application, for accelerated approval of the cell therapy, was backed by data from a Phase 2 study, which featured an open label extension study and natural history comparisons from FDA-funded datasets. The FDA rejected the therapy in July 2025, saying in its complete response letter (CRL) that the data package fell short of the “statutory requirement for substantial evidence of effectiveness.” The FDA’s July decision surprised Capricor CEO Linda Marbán, who in a statement at the time said the biotech had “followed [the FDA’s] guidance throughout the process.” The use of an externally controlled study was “one of the major issues” raised in the CRL, Marbán said during a BioSpace webinar earlier this year. With Capricor now armed with positive results from a placebo-controlled pivotal trial, will the FDA’s revised stance on external controls bolster deramiocel’s chances? Skyhawk’s Huntington’s drug could take earlier flight Skyhawk reported positive data earlier this month from a Phase 1/2 trial leveraging an external control comparator. After 12 months, SKY-0515, a small molecule RNA splicing modifier in development for Huntington’s disease, improved scores from baseline on the Composite Unified Huntington’s Disease Rating Scale (cUHDRS) compared to a natural history dataset of symptomatic patients. Skyhawk already has 144 patients enrolled in its pivotal placebo-controlled Phase 2/3 FALCON-HD study, but Haney said the company has had discussions with the FDA about a potentially accelerated timeline. “They are encouraging us to look for the fastest way we can move responsibly for patients, and we want to do that,” he continued. “I really admire the FDA for being willing to reopen something that they had closed,” Haney added of the agency’s recent reversals on uniQure, REGENXBIO and more. And if AMT-130 gets the regulatory greenlight, he expressed optimism about Skyhawk’s chances. “It makes a lot of sense that you would treat various drugs addressing the same patient population according to the same evaluative standards,” Haney said. “So I expect the FDA will do that.” A second chance for Biohaven’s SCA drug? The FDA in the past year has also strongly encouraged the use of real-world data. Biohaven’s troriluzole, in development for spinocerebellar ataxia (SCA), was rejected by the FDA in November 2025. In its new drug application, Biohaven relied on a one-year placebo-controlled study and a three-year real-world evidence study, which met its primary and secondary outcome efficacy endpoints. In its CRL, the FDA cited “issues that can be inherent to real-world evidence and external control studies including potential bias, design flaws, lack of pre-specification and unmeasured confounding factors,” according to a company press release at the time. Biohaven has “spent considerable time advocating” for troriluzole in SCA in the past year, CEO Vlad Coric told BioSpace earlier this month. “We stand by the data and believe this is an approvable package, and we are continuing to interact with the FDA, and we will not stop advocating for patients that this should be approved.” Over the past month, several rare disease drug developers, including Disc Medicine and Replimune , have announced new alignment with the FDA regarding their own recently rejected drugs. Will Biohaven be next? Rare diseases Biohaven Cuts R&D Spending by 60% After FDA Rejection of Drug for Rare Neurodegenerative Disease Biohaven is proposing troriluzole for the treatment of spinocerebellar ataxia, a group of rare, genetic diseases that lead to the progressive loss of control over movement. November 5, 2025 · 2 min read · Tristan Manalac Read more Stoking an expedited pathway for Dravet ASO? Like Skyhawk, Capricor and Biohaven, Stoke Therapeutics has its bases covered. The Massachusetts-based biotech is currently conducting a sham-controlled Phase 3 trial for its Biogen-partnered lead candidate zorevunersen in Dravet syndrome, a rare and severe form of epilepsy. However, Stoke has had discussions with the FDA about potential expedited regulatory pathways based on its Phase 1/2a trial and open-label extension, as well as data from a two-year natural history study, a company spokesperson told BioSpace in April. In December 2025, Stoke reported long-term data comparing patients treated with zorevunersen across its clinical development program versus natural history controls. Comparisons were adjusted by baseline differences between these two patient groups in an effort to mimic randomization, according to the biotech’s press release at the time. Patients on zorevunersen saw a statistically significant decrease in the frequency of major motor seizures—a hallmark of Dravet—at six months versus external controls. Stoke expects data from the Phase 3 trial in mid-2027, according to a January company update , with a rolling NDA submission planned to start in the first half of next year. FDA At FDA, ‘caretaker mode’ is better than power trip mode UniQure’s planned third-quarter submission for its Huntington’s disease gene therapy may be a harbinger of a more flexible FDA under acting commissioner Kyle Diamantas—but how long will it last? And how can companies be sure these positive decisions won’t just be reversed? June 18, 2026 · 6 min read · Heather McKenzie Read more

California-based Protillion Biosciences, Inc. and Merck (NYSE: MRK) have announced a multi-target drug discovery collaboration and license agreement that gives Merck access to Protillion’s proprietary protein engineering platform across multiple undisclosed therapeutic programs. The deal carries potential milestone payments of up to USD 510 million, making it a material commercial validation for a venture-backed company that has not yet disclosed clinical-stage assets. Protillion is backed by ARCH Venture Partners and Illumina Ventures and was co-founded by CEO Curtis Layton and Stanford University professor Will Greenleaf. At the center of the agreement is Protillion’s Prot-MaP technology, a megascale data generation platform that produces high-throughput quantitative datasets for training protein design AI systems. The platform uses purpose-built, fully automated instrumentation to characterize millions of protein variants per run, generating what the company describes as just-in-time training sets for AI-driven biologics optimization. The approach is intended to address model overfitting, a known limitation of AI systems trained on sparse or low-diversity datasets. Protillion reports the platform can identify optimized biologics with complex therapeutic profiles — including pH-dependent sweeping and multi-target specificity — that are difficult to achieve through conventional methods. The collaboration is focused on biologics discovery, with Merck contributing its internal drug discovery expertise to advance candidate identification across multiple targets. Under the terms of the agreement, Protillion will receive an undisclosed upfront payment in addition to eligibility for research, development, and commercial milestone payments totaling up to USD 510 million across multiple programs. The milestone figure excludes the upfront component, making the total potential deal value higher than the disclosed ceiling. No per-program milestone breakdown, royalty structure, territorial carve-outs, or equity component was disclosed. The agreement covers multiple therapeutic targets, though specific indications were not named in the announcement. The deal follows a period of organizational build-out at Protillion, including the appointment of Robert Hollingsworth as Chief Scientific Officer in March 2026. Hollingsworth brings more than 30 years of drug development experience, most recently as CSO at Shoreline Therapeutics and previously as Vice President and CSO of Cancer Vaccines and Immunotherapeutics at Pfizer. Merck has been a consistent dealmaker in AI-enabled and platform-based drug discovery, having partnered with Quotient Therapeutics on a somatic genomics collaboration for inflammatory bowel disease targets worth up to USD 2.2 billion in March 2026, and with Skyhawk Therapeutics on an RNA-targeting small molecule collaboration for neurological disorders valued at over USD 2 billion in August 2025. Among AI-enabled biologics discovery companies, Absci is perhaps the closest comparator, having built a business around large-scale experimental data generation coupled with generative antibody design. Other players, including Twist Bioscience, provide high-throughput synthetic biology and screening capabilities that support biologics discovery but operate under different business models. This article was generated with AI assistance and reviewed and edited by the AllSci editorial team Explore more at AllSci News: https://allsci.com/news/ Your email address will not be published. Required fields are marked * Comment * Name * Email * Website Copyright © 2026. AllSci Corp. All rights reserved.