August 22, 2019 Press Release

Imbrium Therapeutics L.P. and SpineThera Announce Issuance of U.S. Patent Covering Composition of Matter Protection for SX600, a Non-Opioid Product in Development for Epidural Steroid Injection for the Treatment of Low Back Pain

SpineThera’s clinical development program for SX600 will evaluate sustained-release, injectable treatment options for pain in and near the spine

STAMFORD, Conn. – August 22, 2019 – Imbrium Therapeutics L.P., a clinical-stage biopharmaceutical company and operating subsidiary of Purdue Pharma L.P., in conjunction with SpineThera, Inc., today announced issuance of U.S. Patent No. 10,350,222 from the United States Patent and Trademark Office. This is the third U.S. Patent to issue covering the development candidate SX600, which is an injectable micro-suspension containing microparticles of a glucocorticoid for treating back pain. The companies previously announced that Purdue Pharma L.P. and SpineThera, Inc., had entered into an agreement that provides Purdue the exclusive option to acquire SpineThera, Inc. and gain worldwide rights to its products and technology platforms, including lead asset SX600.

“We are pleased with the continued evolution of the patent portfolio of SX600” said Paul Medeiros, president of Imbrium Therapeutics. “The issuance of this new patent acknowledges the novelty of this formulation, and its availability will support our work to meet the important medical need for non-opioid alternatives for the treatment of chronic pain.”  

“As we progress with the development of SX600, a unique and innovative sustained-release, injectable, micro-suspension corticosteroid, this new patent strengthens and broadens our intellectual property portfolio, and helps us to address the unique needs of patients who require an epidural injection to treat back pain” said Jeff Missling, founder and CEO of SpineThera.

Patent No. 10,350,222 provides composition of matter protection for SX600 and complements previously issued U.S. Patent Nos. 8,927,529 and 9,572,771, which provide protection to methods of treatment. The active ingredient in SX600 is dexamethasone acetate, which has been reformulated into an injectable micro-suspension containing microparticles that are smaller than the particles in a standard corticosteroid suspension and smaller than a red blood cell. The active drug is encapsulated within these tiny biodegradable microparticles, which provide sustained release delivery of dexamethasone.  

“We are pleased with SpineThera’s progress in developing their novel epidural steroid injection for patients who suffer from low back pain,” said Craig Landau, MD, president and CEO, Purdue Pharma. “We remain committed to addressing the needs of pain patients through new and innovative non-opioid medicines such as SX600. If approved by FDA, SX600 could represent the first and only steroid injection indicated for epidural administration.”  

This press release discusses investigational uses of an agent in development and is not intended to convey conclusions about efficacy or safety. There is no guarantee that SX600, an investigational agent, will successfully complete development or gain FDA approval.

About Imbrium Therapeutics L.P.

Imbrium is a clinical-stage biopharmaceutical company dedicated to advancing medical science through the development of important new pharmacologic and biologic therapeutics. We are pursuing oncology chemotherapeutics, treatments for disorders of the central nervous system, and non-opioid approaches to the management of pain. As an operating subsidiary of Purdue Pharma L.P., Imbrium strives to develop and bring to market new medicines that serve the unmet needs of patients, physicians and health systems worldwide. We have built a robust and diversified pipeline of investigational drug candidates, and we actively collaborate with industry and academic partners to identify and advance future impactful medicines. For more information, please visit

About SpineThera

SpineThera designs and develops sustained-release, injectable drugs to meet the unique safety requirements for administration in and near the spine. Our goal is to develop proprietary drugs that offer patients and physicians new treatment options that reduce risk, improve outcomes, and manage overall treatment costs in markets with few or no approved drugs. SX600, our lead product candidate, is an investigational drug.

# # #