Syndax Pharmaceuticals Inc.
SNDXHeld by 10 specialist biotech funds
High ConvergenceHigh short interest · No specialist buying10 funds opened new positions. Next phase2 readout (Axatilimab): Apr 2023. Short interest: 20.8% of float.
Held by 10 specialist biotech funds
High ConvergenceHigh short interest · No specialist buying10 funds opened new positions. Next phase2 readout (Axatilimab): Apr 2023. Short interest: 20.8% of float.
Syndax Pharmaceuticals, Inc. operates as a clinical-stage biopharmaceutical firm focused on developing innovative therapies for cancer. Among its leading investigational products are SNDX-5613, currently undergoing Phase 1/2 clinical assessment, which targets the Menin-mixed lineage leukemia 1 protein interaction for treating MLL-rearranged (MLLr) and nucleophosmin 1 mutant acute myeloid leukemia (NPM1c AML). Another significant candidate is SNDX-6352, or axatilimab, a monoclonal antibody designed to block the colony stimulating factor 1 (CSF-1) receptor, intended for patients suffering from chronic graft versus host disease (cGVHD). The company is additionally progressing Entinostat. Syndax has also established strategic collaborations, including a research and development agreement with the National Cancer Institute, a clinical trial agreement with the Eastern Cooperative Oncology Group, and a license agreement with Kyowa Hakko Kirin Co., Ltd. Founded in 2005, Syndax Pharmaceuticals, Inc. maintains its corporate headquarters in Waltham, Massachusetts.
See how each signal contributes — fund overlap, insider activity, catalyst timing, short interest (free trial)
10 specialist funds hold SNDX with a Phase 2 in 427 days for revumenib (Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Mixed Lineage Acute Leukemia)
+1 more upcoming catalyst
Position history (shares)
Tang Capital — a specialist event-driven fund with deep biotech expertise — fully exited SNDX despite a credible upcoming catalyst stack including a Phase 3 readout for revumenib in AML (expected mid-2029) and a Phase 2 readout for axatilimab in IPF (September 2026). The exit is a notable negative signal given Tang's track record of holding through binary events, and stands in contrast to 10 specialist funds — including OrbiMed, Cormorant, and Deerfield — that remain long, suggesting a divergence in conviction rather than broad capitulation.
7 quarters
Feb 17, 2026
$0
0 funds
Mar 16, 2026
$0
0 funds
May 15, 2026
$110.8M
2 funds
Aug 14, 2026
$116.3M
2 funds
+530% total institutional value over 23 quarters
Total Liquidity
$547.9M
Quarterly Burn
$80.6M
Runway
6.8 quarters
As of
Jun 30, 2026
Short Shares
18.23M
Change
-15.9%
Days to Cover
10.1
% of Float
20.8%
Settlement
Sep 30, 2026
Short interest over 12 periods
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# Investment Summary: Axatilimab Safety Signal This case report documents pulmonary alveolar proteinosis (PAP) developing in an allogeneic stem cell transplant patient receiving axatilimab for chronic graft-versus-host disease (cGVHD), raising a potential safety concern for Syndax's lead candidate. While a single case report cannot establish causation in the context of multiagent GVHD therapy and post-transplant complications, it warrants monitoring for whether similar pulmonary adverse events emerge in ongoing axatilimab trials or post-market surveillance. This finding could impact the risk-benefit profile positioning and label restrictions, particularly if pulmonary toxicity signals accumulate in the cGVHD patient population.
# Investment Summary: Syndax Revumenib Safety Profile **Clinical/Commercial Implication:** This post-marketing safety analysis of revumenib (Syndax's menin inhibitor) using Bayesian disproportionality methods identifies adverse event signals in real-world use beyond initial clinical trial data, which is critical for labeling updates, risk management strategies, and potential market access restrictions. Safety signals detected in national pharmacovigilance databases could affect patient eligibility, prescriber confidence, and revenue trajectory if serious or frequent adverse events require additional monitoring or contraindications. The timing of this 2026 analysis suggests revumenib has sufficient market penetration to generate meaningful post-approval data, making the safety findings directly relevant to competitive positioning, payer coverage decisions, and long-term commercial viability of this indication. **Why This Matters:** Post-marketing safety data can materially impact peak sales forecasts and market exclusivity
# Summary for SNDX Investors This case report describes successful salvage therapy with revumenib (a KMT2A inhibitor) in a patient with isolated leukemia cutis, demonstrating potential clinical utility in extramedullary disease where standard therapies fail. The finding is notable because it suggests revumenib may address an underserved patient population with KMT2A-rearranged acute leukemias presenting with cutaneous manifestations, potentially expanding the addressable market beyond primary hematologic indications. However, this represents a single case study rather than systematic evidence; investors should await prospective data on revumenib's efficacy in extramedullary disease to assess meaningful commercial impact on SNDX's marketed or pipeline assets.
# Investment Summary: Syndax Pharmaceuticals (SNDX) **Clinical Finding:** The all-oral triplet combination of revumenib (SNDX-5613, Syndax's menin inhibitor), decitabine, and venetoclax demonstrated efficacy in relapsed/refractory AML, with potential to address a high-mortality patient population where treatment options are limited. **Commercial Implication:** If data supports favorable safety/efficacy profiles and regulatory approval, this combination could establish revumenib as a cornerstone agent in relapsed/refractory AML, expanding addressable market beyond monotherapy and potentially capturing combination therapy revenue streams alongside established agents (decitabine, venetoclax). **Investor Relevance:** Success here validates revumenib's clinical utility and strengthens Syndax's pipeline valuation; however, outcomes will depend on complete response rates, durability, and safety
# Investment Summary: SNDX Revumenib Case Report This case report documents clinical efficacy of revumenib (SNDX-5613), Syndax's menin inhibitor, in treating lineage switch infant leukemia—a rare but aggressive pediatric malignancy with limited treatment options. The successful response followed by hematopoietic cell transplantation demonstrates revumenib's potential utility in high-risk pediatric leukemia populations, though the case-report nature limits generalizability to broader commercial applicability. For investors, this adds clinical evidence supporting revumenib's label expansion potential in pediatric hematologic malignancies beyond the current approved adult KMT2r-rearranged acute leukemia indication, though regulatory pathway and market size for this rare pediatric subset remain uncertain.
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