Ulixacaltamide
From Wikipedia, the free encyclopedia
- PRAX-944
- Z-944
- US: Investigational (Breakthrough Therapy)
- Investigational
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| Routes of administration | Oral |
| Drug class | T-type calcium channel blocker |
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| Formula | C19H27ClFN3O2 |
| Molar mass | 383.89 g·mol−1 |
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Ulixacaltamide (developmental codes PRAX-944 and Z-944) is an investigational new drug developed by Praxis Precision Medicines for the treatment of essential tremor (ET).[1] It is a small molecule designed to selectively inhibit T-type calcium channels, reducing the abnormal neuronal burst firing in the cerebello-thalamo-cortical (CTC) circuit that is believed to cause tremors.[2]
In October 2025, the drug met its primary endpoints in the pivotal Phase 3 Essential3 clinical program.[3] Following these results, the U.S. Food and Drug Administration (FDA) granted ulixacaltamide Breakthrough Therapy Designation in December 2025.[4] In February 2026, the company submitted a New Drug Application (NDA) to the FDA, which was accepted for review in April 2026 with a target action date of January 2027.[5]
Ulixacaltamide is being developed specifically for the treatment of essential tremor in adults. If approved, it would represent a new pharmacological class of treatment for the condition, distinct from the current standard-of-care agents such as propranolol (a beta-blocker) and primidone (an anticonvulsant).[2]
In December 2025, the FDA granted the drug Breakthrough Therapy Designation, a status intended to expedite the development and review of drugs for serious conditions where preliminary clinical evidence indicates the drug may demonstrate substantial improvement over available therapies. The designation was supported by Phase 3 clinical results demonstrating superiority over propranolol, the only currently FDA-approved pharmacologic treatment for essential tremor.[6][4]
Mechanism of action
Ulixacaltamide is a selective blocker of T-type calcium channels (Cav3.1, Cav3.2, and Cav3.3 isoforms).[2]
Research suggests that the involuntary rhythmic shaking characteristic of essential tremor is driven by abnormal oscillatory activity within the cerebello-thalamo-cortical circuit. Specifically, T-type calcium channels play a key role in generating "burst firing" patterns in neurons within this pathway. By inhibiting these channels, ulixacaltamide is designed to suppress this pathological burst firing and reduce tremor amplitude without causing the widespread central nervous system depression often associated with non-selective treatments.[7]