Dogwood Therapeutics Nears Phase 2b Readout for Halneuron Neuropathic Pain Treatment

Dogwood Therapeutics expects top-line Phase 2b results later this fall for Halneuron, its investigational treatment for moderate-to-severe chemotherapy-induced neuropathic pain. The randomized, placebo-controlled trial has enrolled 232 patients, near its target of 210–240. An interim analysis showed a treatment trend separating from placebo, with a low 4.4% dropout rate, though the study remains blinded and the result is not yet confirmed. The primary endpoint is the share of patients achieving at least a 50% pain reduction after four weeks. If results are positive, Dogwood plans FDA discussions in the fourth quarter, a synthetic-material pharmacokinetic study and two Phase 3 trials in the second half of next year, with a potential new drug application submission targeted for the second half of 2029.

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.

Halneuron is a formulation of tetrodotoxin, or TTX, administered by subcutaneous injection. Dogwood says the drug inhibits the NaV1.7 voltage-gated sodium channel, which is involved in peripheral pain signaling. Duncan said the compound does not cross the blood-brain barrier and has shown a tolerable safety profile in prior clinical studies, though the ongoing Phase 2b trial remains blinded.

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 ri...