INmune Bio's Alzheimer's Drug XPro Misses Primary Endpoint in Phase 2 Trial, Company Focuses on Subgroup Efficacy

INmune Bio's phase 2 study of its TNF inhibitor XPro in Alzheimer's disease has failed to meet its primary endpoint, leading to a significant drop in the company's share price. Despite the setback, the biotech firm is highlighting positive results in a predefined subgroup and exploring potential partnering opportunities.

Trial Results and Market Response

The phase 2 trial, designed to investigate the effects of targeting neuroinflammation in Alzheimer's disease, did not show a significant improvement in cognition as measured by the EMACC scale after six months of treatment. Patients receiving XPro performed no better than those on placebo in the overall study population of 200 patients.

Following the announcement, INmune Bio's stock price plummeted by 60% in premarket trading, settling at $2.17 per share. This dramatic decline reflects investor disappointment in the drug's performance and uncertainty about its future prospects.

Subgroup Analysis and Potential Path Forward

Despite missing the primary and secondary endpoints in the overall population, INmune Bio is emphasizing positive results observed in a predefined subgroup of 100 amyloid-positive early Alzheimer's patients with two or more biomarkers of inflammation. The company reported a clinical benefit of XPro over placebo on the EMACC measure and the secondary endpoint neuropsychiatric inventory in this subpopulation.

Additionally, INmune linked XPro to changes in the biomarker pTau217 in the subgroup. The effect sizes reportedly exceeded the 0.2 threshold, which is considered preliminary evidence of potential efficacy in early-phase trials, according to Judith Jaeger, Ph.D., a consultant to INmune on the trial.

Financial Considerations and Future Plans

INmune Bio finds itself at a crossroads, requiring additional financial resources to advance XPro's development. The company ended March with $19.3 million in cash and recently closed a $19 million financing round. However, given the trial results, securing further funding may prove challenging.

CEO Raymond Tesi acknowledged the need for additional work and financial support. The company plans to explore partnering opportunities while preparing to present additional analyses of the data and engage in discussions with the FDA. INmune Bio aims to leverage the positive subgroup results to chart a path forward for XPro in what they describe as an "easily defined and commercially relevant patient population with early Alzheimer's disease."