This OT Award funds clinical trials within The Early Phase Pain Investigation Clinical Network (EPPIC-Net). EPPIC-NET is part of the NIH Helping to End Addiction Long-term (HEAL) Initiative. More than 100 people die each day of opioid-related overdoses. Many of these can be traced to addiction related to the treatment of acute and chronic pain. There is an urgent need to develop non-addictive pain treatments to limit opioid exposures that can lead to addiction, as well as to treat pain conditions that are currently without effective treatments. The EPPIC- Net OT provides a robust infrastructure for the rapid design and execution of high-quality early phase clinical trials to test promising novel therapeutics and devices for the treatment of pain and for carrying out in-depth phenotyping and biomarker studies in patients with specific pain conditions. Such studies bring intense focus to patients with well-defined pain conditions and high unmet therapeutic needs. Studies funded under this award are described below. EPPIC-Net Clinical Trial EN20-01 Project Title: A 24-week Week Study to Evaluate the Safety and Efficacy of CNTX-6970 in Subjects with Moderate to Severe Knee Osteoarthritis Pain. This trial will test the novel oral drug CNTX-6970 in patients with moderate to severe knee osteoarthritis pain. 150 participants will be enrolled at 20 EPPIC-Net sites across the U.S. Preclinical studies of CNTX-6970, a C-C chemokine type 2 (CCR2) receptor antagonist, demonstrated potent analgesia in multiple pain models. Phase 1 clinical studies showed robust and dose-proportional target engagement and no emergent safety issues. The rationale for exploring CNTX-6970 for the management of pain in knee osteoarthritis stems from the emerging understanding of the pathophysiology of the affected joint as well as CNTX-6970 effects on neural signaling. Participants will be randomized to receive CNTX-6970, placebo, or an approved pain medication and will be followed for 24 weeks. EPPIC-Net Master Protocol to Assess Treatments for Painful Diabetic Peripheral Neuropathy People with diabetes are at risk for painful diabetic peripheral neuropathy. Diabetic neuropathic pain may be experienced as burning, aching, hypersensitivity to touch, or simply as pain. The currently FDA-approved medications for painful diabetic peripheral neuropathy (PDPN) provide inadequate pain relief for many. The EPPIC-Net Master Protocol for Diabetic Peripheral Neuropathy (Master Platform Protocol (MPP)) provides a platform for EPPIC-Net Phase II clinical trials testing therapeutic assets for the treatment of PDPN. The MPP provides the common over-arching structure with a modular design of required and optional elements to be included for study of each asset. All clinical trials under the MPP include HEAL Common Data Elements and required PDPN assessments as well as asset-specific procedures and measurements described in an Intervention Specific Appendix (ISA) to the MPP. The following EPPIC-Net Clinical Trials will be conducted under the EPPIC-NET Master Protocol to assess treatments for painful diabetic peripheral neuropathy: EPPIC-Net Clinical Trial EN21-01 Project Title: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Safety and Efficacy of 80mg daily of NRD135S.E1 Versus Placebo in Adult and Elderly Participants with Painful Diabetic Peripheral Neuropathy (SERENDIPITY-1) This award is for a clinical trial under the EPPIC-Net Master Protocol for Painful Diabetic Peripheral Neuropathy. The identification of NRD135S.E1 as a potential pain treatment is a true “bedside-to-bench" story in modern-day translational medicine. NRD135S.E1 is a small molecule, a lab-optimized version of a natural substance traditionally used in a village in Siberia to brew tea to treat pain. In clinical studies, NRD135S.E1 was well tolerated by participants and showed clinically relevant pain relief. Study in EPPIC-Net will further development of this therapeutic asset as a possible treatment for painful diabetic peripheral neuropathy (PDPN). 260 adult participants with PDPN will be randomized to NRD135S.E1 or placebo in the 12-week, parallel design trial. EPPIC-Net Clinical Trial EN21-02 Project Title: A Randomized, Double-blind, Placebo-controlled, Parallel, 20-week, Phase 2b Study of Topical Pirenzepine (WST-057) or Placebo in Type 2 Diabetes Mellitus Patients with Painful Diabetic Peripheral Neuropathy This award is for a clinical trial under EPPIC-Net Master Protocol for Painful Diabetic Peripheral Neuropathy to test a potential new topical treatment for painful diabetic peripheral neuropathy. The therapeutic asset, WST-057 (topical pirenzepine 4%), is a molecule that was developed in the 1980s and marketed throughout Europe and Asia in an oral form to treat gastric ulcers. Preliminary studies showed an increase in nerve fiber density in the skin, suggesting it can enhance nerve regrowth and may help alleviate pain in painful diabetic peripheral neuropathy as well. This EPPIC-Net study will enroll 260 participants at 12 clinical sites. Participants will be randomized to apply WST-057 or a matching placebo cream to the feet and calves for 20-weeks.