Syndax Pharmaceuticals Inc

Current report

Our products and product candidates may cause undesirable side effects or have other properties that could delay or prevent their regulatory approval, limit the commercial scope of their approved use, or result in significant negative consequences following any marketing approval.

Current report

Undesirable side effects caused by our products and product candidates could cause the interruption, delay or halting of the trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or other foreign regulatory authorities. For example, the Revuforj U.S. Prescribing Information label contains a boxed warning for differentiation syndrome, which can be fatal, as well as QTc prolongation and Torsades de Pointes. Results of the clinical trials may reveal a high and unacceptable severity and prevalence of side effects or other unexpected characteristics. In such event, the trials could be suspended or terminated, or the FDA or foreign regulatory authorities could deny approval of our product candidates for any or all targeted indications. Drug-related side effects could affect patient recruitment or the ability of enrolled subjects to complete the trial or result in potential product liability claims. Any of these occurrences may harm our business, financial condition and prospects.

Current report

Additionally, if our product candidates receive marketing approval, and we or others later identify undesirable side effects, a number of potentially significant negative consequences could result, including:

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we may suspend marketing of, or withdraw or recall, the product;

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regulatory authorities may withdraw approvals;

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regulatory authorities may require additional warnings on the product labels;

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the FDA or other regulatory authorities may issue safety alerts, Dear Healthcare Provider letters, press releases or other communications containing warnings about the product;

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the FDA may require the establishment or modification of a risk evaluation and mitigation strategy or foreign regulatory authorities may require the establishment or modification of a similar strategy that may, for instance, restrict distribution of the product and impose burdensome implementation requirements on us;

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regulatory authorities may require that we conduct post-marketing studies;

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our reputation may suffer.

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Any of these events could prevent us from achieving or maintaining market acceptance of our product candidates for use in targeted indications or otherwise materially harm its commercial prospects, if approved, and could harm our business, results of operations and prospects.

Current report

Revuforj, Niktimvo and any product candidate that receives approval in the future would face significant competition from other therapies in the relevant indication. For example, cGVHD has historically been managed by off-label treatments. However, in the past several years, the FDA has approved three drugs, ibrutinib (Imbruvica®), belomosidil (Rezurock®) and ruxolitinib (Jakafi®), for use in patients with cGVHD after failure of one or more lines of systemic therapy. All three of these drugs may compete with Niktimvo in patients diagnosed with cGVHD.

Current report

We initially developed revumenib for the treatment of R/R adult and pediatric patients with KMT2Ar ALL, KMT2Ar AML and NPM1 mutant AML. At this time, other than Revuforj, there are no drugs approved for these defined populations and patients are managed using the standard of care treatment regimens developed for general AML and ALL populations. However, there are other agents in development for similar populations that may in the future be approved for these defined populations and that may prove to be more effective than Revuforj. We are also advancing a pipeline of frontline trials of revumenib in combination with standard of care therapies to support potential additional listings in the National Comprehensive Cancer Network, or NCCN, Guidelines® and/or label expansion opportunities.

Current report

Existing or potential competitors have or may have substantially greater financial, technical and human resources than we do and significantly greater experience in the discovery and development of product candidates, obtaining FDA and other regulatory approvals of product candidates and the commercialization of those products. Our competitors may be more successful than us in obtaining FDA approval for drugs and achieving widespread market acceptance. Our competitors’ drugs may be more effective or more effectively marketed and sold than any drug we may commercialize and may render our product candidates obsolete or non-competitive before we can recover the expenses of developing and commercializing any of our product candidates. Our competitors may also obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours. We anticipate that we will face intense and increasing competition as new drugs enter the market and advanced technologies become available.

Current report

We believe that our ability to successfully compete will depend on, among other things:

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the market adoption of Revuforj, Niktimvo and our product candidates by physicians and patients;

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the efficacy and safety profile of our product candidates relative to marketed products and product candidates in development by third parties;

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the time it takes for our product candidates to complete clinical development and receive marketing approval;

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our ability to commercialize Revuforj, Niktimvo and our product candidates if they receive regulatory approval;

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the price of Revuforj, Niktimvo and our product candidates, including in comparison to branded or generic competitors;

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whether coverage and adequate levels of reimbursement are available under private and governmental health insurance plans, including Medicare;

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our ability to manufacture commercial quantities of Revuforj, Niktimvo and our product candidates, if they receive regulatory approval; and

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our ability to negotiate preferential formulary status for our product candidates.

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Even if we obtain regulatory approval of our other product candidates, the availability, commercial formulary placement, and price of our competitors’ products could limit the demand and the price we are able to charge. We may not be able to implement our business plan if the acceptance of our product candidates is inhibited by price competition or the reluctance of physicians to switch from existing methods of treatment, or if physicians switch to other new drug or biologic products or choose to reserve our drugs for use in limited circumstances.

Current report

Off-label use or misuse of our products may harm our reputation in the marketplace or result in injuries that lead to costly product liability suits.

Current report

We have received regulatory approval to market Revuforj in the U.S. for the treatment of (i) R/R acute leukemia with a KMT2A translocation in adult and pediatric patients one year old and older and (ii) R/R AML with a susceptible NPM1 mutation in adult and pediatric patients one year and older who have no satisfactory alternative treatment options, and regulatory approval to market Niktimvo for the treatment of cGVHD after failure of at least two prior lines of systemic therapy in adult and pediatric patients weighing at least 40 kg. We may only promote or market Revuforj, Niktimvo, and our other product candidates, if approved by the FDA, for their specifically approved indications and in a manner consistent with the approved labeling. We train our marketing and sales force against promoting our product candidates for uses outside of the approved indications for use, known as “off-label uses.” We cannot, however, prevent a physician from using our products off-label, when in the physician’s independent professional medical judgment, he or she deems it appropriate. Furthermore, the use of our products for indications other than those approved by the FDA may not effectively treat such conditions. Any such off-label use of our product candidates could harm our reputation in the marketplace among physicians and patients. There may also be increased risk of injury to patients if physicians attempt to use our products for any off-label uses, which could lead to product liability lawsuits that might require significant financial and management resources and that could harm our reputation. Additionally, the FDA imposes stringent restrictions on manufacturers’ communications regarding off-label uses and if we, or our collaborators, do not promote our products in a manner consistent with the approved labeling, we, or they, may be subject to warnings or enforcement action for off-label marketing. Violation of the Federal Food, Drug, and Cosmetic Act, or FCA, and other statutes, including the FCA, relating to the promotion and advertising of prescription drugs may lead to investigations or allegations of violations of federal and state healthcare fraud and abuse laws and state consumer protection laws.

Current report

Disruptions at the FDA, the SEC and other government agencies and regulatory authorities caused by funding shortages or a government shutdown could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

Current report

The ability of the FDA and comparable foreign regulatory authorities to review and approve new products can be affected by a variety of factors, including government budget and funding levels, government shutdowns, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable.

Current report

Disruptions at the FDA and other agencies and comparable regulatory authorities may also slow the time necessary for new drugs or biologics to be reviewed and/or approved by necessary government agencies and regulatory authorities, which would adversely affect our business. For example, over the last several years, including the ongoing government shutdown that began on October 1, 2025, and previously from December 22, 2018 to January 25, 2019, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA and the SEC, have had to furlough critical FDA, SEC and other government employees and stop critical activities. If the current government shutdown continues or a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business