Dogwood Therapeutics (NASDAQ:DWTX) said its Phase 2b study of Halneuron, an investigational treatment for chemotherapy-induced neuropathic pain, has enrolled more than 230 patients and is expected to report top-line data later this fall.
During a virtual key opinion leader event, Chief Executive Officer and Chairman Greg Duncan said the company is targeting moderate-to-severe chemotherapy-induced neuropathic pain, or CINP, in cancer survivors. He described the condition as a significant unmet need that can lead oncologists to reduce chemotherapy doses, extend intervals between treatments or discontinue chemotherapy in severe cases.
Phase 2b study nears completion
Chief Medical Officer Mike Gendreau said the randomized, placebo-controlled Phase 2b trial is evaluating eight injections over 14 days, followed by two weeks without treatment. The primary endpoint assesses the proportion of patients achieving at least a 50% reduction in pain from baseline at week four.
The study’s target enrollment was 210 to 240 patients. Gendreau said 232 patients had been recruited as of the event, with the final patient expected to be randomized that week. The company expects results later in the fall.
An independent interim analysis of the first 97 participants found a treatment pattern trending toward separation from placebo, according to Gendreau. He said the analysis indicated that a sample size of 210 to 240 patients would provide 80% statistical power to detect a significant result if observed trends continued. The analysis did not unblind Dogwood’s clinical team to treatment-group results.
Gendreau also highlighted a 4.4% dropout rate in the interim population. He said participants had experienced moderate-to-severe neuropathic pain for an average of approximately five years following chemotherapy, and at least two-thirds reported previous treatment with pain medicines such as duloxetine, pregabalin or gabapentin. The protocol allows patients to remain on certain background pain medications if they continue to meet study-entry pain criteria.
Dogwood is also conducting an open-label extension for patients completing the double-blind portion of the study. Patients may receive two or four injections each month over 12 weeks depending on reported pain levels. As of the company’s August update, 189 patients had completed the double-blind study and 65 had entered the open-label phase, with that figure subsequently rising into the 80s, Gendreau said.
Mechanism and prior clinical data
Iain Dukes, a venture partner at OrbiMed and chairman of Dogwood’s scientific advisory board, said NaV1.7 helps set the threshold for peripheral pain-signal transmission, while NaV1.8 may affect the duration or intensity of signaling. He said NaV1.7 has genetic validation as a pain target because people with loss-of-function variants can have congenital insensitivity to pain.
Dukes said tetrodotoxin has its highest potency against NaV1.7, followed by NaV1.4, and binds at a different site than traditional sodium-channel blockers such as lidocaine. He also said the compound’s limited blood-brain-barrier penetration may provide functional selectivity.
Gendreau cited a prior 165-patient cancer-related pain study in which patients received tetrodotoxin or placebo twice daily for four days. He said 51% of treated patients met the study’s responder definition, compared with 35% of placebo recipients. Among responders, he said the average duration of response was 57 days in the tetrodotoxin group versus 10.5 days for placebo responders, despite treatment lasting four days.
Dogwood selected a once-daily 30-microgram regimen for the current Phase 2b trial following a prior dose-ranging CINP study, Gendreau said.
Synthetic manufacturing and Phase 3 plans
The company is transitioning from naturally sourced tetrodotoxin to a synthetic version for future development. Chemistry and manufacturing specialist Jerry Evarts said Dogwood completed its first synthetic good-manufacturing-practice batch in July, producing approximately 4 grams of material. At a 30-microgram dose, he said that amount represents about 130,000 doses.
Evarts said the company is working toward larger-scale production, targeting eventual 20-gram commercial batches. Dogwood plans to use the synthetic material in a pharmacokinetic crossover study comparing it with naturally sourced tetrodotoxin before entering Phase 3.
Duncan said Dogwood expects to begin Food and Drug Administration interactions in the fourth quarter and plans to initiate two Phase 3 studies in the second half of next year, assuming supportive Phase 2b results. The company is targeting a new drug application submission in the second half of 2029.
Beyond CINP, Duncan said Dogwood may explore Halneuron in diabetic peripheral neuropathy, pain prevention during chemotherapy and acute pain associated with ambulatory surgery. The company also plans to begin a National Cancer Institute-funded study of SP16, its separate LRP-1 agonist program intended to prevent neuropathy during chemotherapy, in the second half of the year.
About Dogwood Therapeutics (NASDAQ:DWTX)
Dogwood Therapeutics is a clinical‐stage biotechnology company dedicated to the discovery and development of novel biologic therapies aimed at reducing fibrosis and promoting tissue repair in cardiovascular and other fibrotic diseases. The company leverages a proprietary Discovery Engine that integrates high‐throughput screening, functional genomics and protein engineering to identify and optimize candidate proteins and antibodies with therapeutic potential.
Dogwood’s lead programs are focused on preventing adverse cardiac remodeling following myocardial injury and improving outcomes in heart failure patients.
