Sorrento Therapeutics Presents Interim Positive Results of Phase 1b Resiniferatoxin (RTX) in Cancer Pain Trial
- Fourteen subjects with advanced cancer pain received epidural RTX (04 to 15 ug)
- Most common treatment-related adverse event was transient post-procedure related pain
- Three subjects at the higher doses had rapid and marked pain reduction after treatment
- One additional cohort was added to further evaluate a 25 ug dose for upcoming Phase 3 studies
Safety in the higher dose cohort is expected to be supportive for testing RTX epidural administration in other advanced non-cancer disease related unmet clinical needs (with a choice of starting dose at 15 or 25 ug depending on the indication considered).
Results as planned in the original study (to 15 ug) are being presented at the
The Phase 1b open-label study was used for dose escalation to assess the safety and preliminary efficacy of a single epidural administration of resiniferatoxin for the treatment of intractable pain due to cancer. Initial expectations for safety and efficacy have been met for the Phase 1b study, though optimal dose selection will follow assessment of the additional dose group in which 25 ug is also being evaluated. Thus far, after
No dose limiting toxicities or notable adverse events unrelated to progression of underlying disease were encountered for any of the subjects. The most common treatment-related adverse event was transient post-procedural pain: 7 of 14 subjects (50%) reported moderate severity. Two additional treatment-related adverse events of moderate severity were back pain and increase in blood pressure in a patient. All events resolved in less than two days following drug administration.
The ongoing trial will follow subjects for at least 84 days. The lower doses of 0.4, 1.0, 2.0, 4.0 ug did not demonstrate notable pain relief, but permitted dose escalation to the next designated dose level based on how well the drug was tolerated.
Three patients had marked pain relief starting shortly after initial administration that were still observed weeks after treatment: 1 of 3 subjects who received 8 ug (a 58-year-old woman with gastrointestinal stromal cancer with severe lower back pain reported a decrease in numerical pain rating scale (NPRS) scores from >6/10 to 2/10), and 2 of 3 subjects who received 15 ug (a 62-year-old man with rectal cancer noted significant improvement in pain, physical strength, mood, and appetite with NPRS scores reduced from 7-8/10 to 3/10; and a 57-year-old man with multiple myeloma and severe pain in his back, hips, and lower extremities subsequently reported mild pain in the target areas after RTX injection). Improvement in pain and mobility within 24 hours of dosing in the three responders at the higher dose levels of RTX suggests the clinical potential of the drug for intractable cancer pain.
Sorrento intends to present the detailed results of the completed study upon completion of the additional expansion cohort later this year. A pivotal Phase 3 trial is being planned using epidural RTX for severe pain states associated with advanced disease.
“We are encouraged by the benefits of using RTX to treat intractable pain in patients with metastatic cancer,” said Associate Professor of Anesthesia,
For access to the scientific presentation (
About Resiniferatoxin (RTX)
A thousand times “hotter” than pure capsaicin (16 Billion Scoville units versus 16M), and with a high affinity for afferent pain nerves, resiniferatoxin binds to TRPV1 receptors and selectively ablates the nerve endings responsible for pain signals experienced by patients1. Delivered peripherally (into the joint space) the transient nerve ending ablation effect can have profound clinical benefits lasting for months to years (as shown in canine studies2).
RTX-001 is a multicenter, open-label dose escalation Phase 1b study to assess the safety and define the maximally tolerated dose of resiniferatoxin administered via the epidural route for the reduction of moderate to severe pain signal intensity associated with advanced cancer. The Phase 1b study is a dose-escalation protocol in which cohorts of patients receive increasing doses of resiniferatoxin until the maximum tolerated dose is achieved. The primary objective of the study is to evaluate the safety of resiniferatoxin and identify the recommended Phase 3 dose. The secondary objective is to assess the preliminary efficacy of resiniferatoxin measured by assessing changes in the intensity of pain using the NPRS score, a widely used proprietary validated pain scale.
RTX is not approved for clinical use by regulatory authorities. Safety and efficacy have not been established.
More information on this trial can be found at www.clinicaltrials.gov (NCT03226574).
Sorrento is a clinical stage, antibody-centric, biopharmaceutical company developing new therapies to turn malignant cancers into manageable and possibly curable diseases. Sorrento's multimodal multipronged approach to fighting cancer is made possible by its extensive immuno-oncology platforms, including key assets such as fully human antibodies (“G-MAB™ library”), clinical stage immuno-cellular therapies (“CAR-T”), intracellular targeting antibodies (“iTAbs”), antibody-drug conjugates (“ADC”), and clinical stage oncolytic virus (“Seprehvir®”).
Sorrento's commitment to life-enhancing therapies for patients is also demonstrated by its effort to advance a first-in-class (TRPV1 agonist) non-opioid pain management small molecule, resiniferatoxin (“RTX”), and ZTlido® (lidocaine topical system) 1.8% for the treatment of post-herpetic neuralgia. Resiniferatoxin is completing a Phase 1b trial for intractable pain associated with cancer and a Phase 1b trial in osteoarthritis patients. ZTlido® was approved by the FDA on
For more information visit www.sorrentotherapeutics.com
This press release and any statements made for and during any presentation or meeting contain forward-looking statements related to
Media and Investor Relations
Sorrento® and the Sorrento logo are registered trademarks of
ZTlido® and G-MAB™ are trademarks owned by
Seprehvir®, is a registered trademark of Virttu Biologics Limited, a wholly-owned subsidiary of
All other trademarks are the property of their respective owners.
Source: Sorrento Therapeutics, Inc.