SignalRx Announces In Silico Design And Discovery Of The First-In-Class HDAC6-BRD4-PI3K Epigenetic Kinase Inhibitor SRX3225

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SignalRx Announces In Silico Design And Discovery Of The First-In-Class HDAC6-BRD4-PI3K Epigenetic Kinase Inhibitor SRX3225

SignalRx Pharmaceuticals Inc., a clinical-stage company developing novel small-molecules therapeutics to inhibit key orthogonal and synergistic oncotargets for the treatment of cancer, today announced the in silico design and discovery of SRX3225, its first-in-class small-molecule potent inhibitor of three key cancer targets HDAC6, BRD4, and PI3K. 

SignalRx's proprietary CRIMP technology platform led to the in silico design and identification of SRX3225 within its triple inhibitor program.  SRX3225 is a novel picomolar potent HDAC6 inhibitor with high selectivity over HDAC1, HDAC2 and HDAC3 isoforms (31-35 times selective) and more so against isozymes HDAC4 through HDAC11 (up to 20,000 times selective). In addition, SRX3225 potently inhibits the epigenetic target BRD4-BD1 with >5X selectivity over BRD4-BD2, and it also potently inhibits PI3K alpha and delta isoforms.  Importantly, because the design of SRX3225 is achieved in silico using cancer targets' structural data, it is possible to independently dial in and out each of the three inhibitory components in a small molecule generating dual and single inhibitory chemotypes from SRX3225.

"This is a huge immuno-oncology breakthrough because it creates a synergistic synthetic lethality effect as a result of PI3K and BRD4 and HDAC inhibition delivered with a single molecule. While dual PI3K/BRD4, dual HDAC/PI3K, and dual BRD4/HDAC inhibitors are under investigation, SRX3225 is the only triple HDAC/PI3K/BRD4 inhibitor that we know of" said SignalRx's scientific advisor and founder Donald L. Durden, MD, PhD. "This new approach of inhibiting three targets simultaneously yields a more complete block of multiple key cancer signaling providing increased lethality coupled with less toxicity than a combination of three single agents.  This novel 3-in-1 anticancer drug paves the way for more sophisticated and cost-effective combinations in cancer patients that should block development of resistance resulting in longer duration of benefits in more patients."

"We achieved this milestone by leveraging the experience in multi-targeted inhibitors and discoveries we have made in our advanced BRD4/PI3K program coupled with the knowledge we have acquired on these targets as exemplified in our recent PNAS publication (" said Dr. Joseph Garlich, Chief Scientific Officer at SignalRx. "Rational combinations of targeted agents in clinical development often face a common detrimental limitation: unwanted additive off-target toxicities from the individual agents used. This leaves no option but to reduce the effective dosages of the agents resulting in less than optimal therapeutic administrations and inefficient treatments. Our approach combines 3 drug mechanisms into one resulting in 1 single agent with a single ADME/safety profile which also simplifies and expedites its development."

SignalRx is interested in partnering discussions to quickly take these novel small molecules through clinical trials together with companion diagnostics for streamlined development and approval.

About SignalRx Pharmaceuticals Inc.

SignalRx is a privately held corporation based in San Diego, CA developing small molecule inhibitors of multiple key signaling pathways in cancer and cancer stem cells.  The company has developed its proprietary CRIMP technology platform to develop new small-molecule therapeutics against more than one target molecule selected from the discovery of synthetic lethalities in cancer cells, epigenetic regulatory processes, immune checkpoints and DNA repair actions.  SignalRx's research programs have novel inhibitors targeting multiple critical onco-targets such as PI3K, MEK, BRAF, IDO1, IDH1, CDK4/6, Wnt, HDAC, DNMT, PARP and BET bromodomains.  SignalRx is leveraging its expertise in novel multi-action inhibitors to develop enhanced anticancer therapeutics with improved efficacy, novel mechanism of action in a single molecule, and the potential to streamline their development. 

Media Contact: Guillermo Morales, SignalRx Pharmaceuticals Inc., 520-777-9609,

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SOURCE SignalRx Pharmaceuticals Inc.

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