Vaccinex Plummets After Lead Drug Flunks Midstage Huntingon's Disease Study

Shares of micro-cap immunotherapy company Vaccinex Inc VCNX were plunging Tuesday in reaction to an adverse readout.

What Happened: Top-line results from the early manifest treatment arm of the Phase 2 SIGNAL study showed that it did not meet the co-primary endpoints, according to the Rochester, New York-based company. 

The study is evaluating its lead product candidate pepinemab in patients with early manifest and prodromal Huntington's disease. 

Pepinemab, a humanized monoclonal antibody, did not meet the two co-primary endpoints: a family of two cognitive assessments from the Huntington's Disease Cognitive Assessment Battery and Clinical Global Impression of Change. 

The investigational asset was well-tolerated, with remarkably low treatment discontinuation and study drop-out rates over the extended 18-month treatment period, Vaccinex said. 

Why It's Important: Huntington's disease is a neurodegenerative disease that affects multiple regions of the brain, with disease progression impacting many critical functions including cognition and motor activity.

No effective disease modifying treatment exists for Huntington's disease. 

What's Next: The data suggests that patients at a somewhat more advanced stage of Huntington's disease may derive the greatest benefit from pepinemab, Vaccinex said.

"The insights gained from this study also suggest that pepinemab might be an important treatment option for Alzheimer's and other neurodegenerative diseases known to primarily affect frontal cortex and to impact cognition," CEO Maurice Zauderer said in a statement.

The company said it has initiated screening and expects to begin enrolling patients this month in a new Alzheimer's disease study of pepinemab at 15 clinical sites in the U.S.

Vaccinex plans to present additional results, including a broader examination of motor activity and outcomes for a smaller group of 86 prodromal subjects, in detail at the upcoming 2020 Huntington's Study Group Conference on Oct. 30 and at subsequent medical conferences.

The company recently announced a collaboration with Merck & Co., Inc. MRK to evaluate pepinemab with the latter's Keytruda in advanced, recurrent or metastatic head and neck squamous cell carcinoma.

VCNX Price Action: At last check, Vaccinex shares were plunging 56.49% to $2.38.

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