- Micro cap Mast Therapeutics (MSTX +23.7%) heads north on a 4x surge in volume. No particular news accounts for the move, but data from a Phase 3 clinical trial, EPIC, assessing lead product candidate vepoloxamer for the treatment of patients with sickle cell disease (SCD) experiencing vaso-occlusive crisis (VOC) are expected this month.
- Investors need to be cautious here. Enrollment was completed in February and the time periods to assess efficacy endpoints were 4 - 14 days which means the company has been "analyzing" the data for six months. If the results were clearly positive, the announcement would most likely have been made promptly. According to a July letter to shareholders, CEO Brian Culley said the company was working diligently to complete the data cleaning, validation and QA/QC work required to lock and unblind the database. Mast is under additional pressure for a positive outcome because it will have to prepay $10M of the principal balance of an outstanding loan if the trial fails.
- VOC, a painful complication of SCD, occurs when the circulation of blood vessels is obstructed by sickled red blood cells. One of the most severe forms of VOC is acute chest syndrome which occurs when blood flow to the lungs is restricted.
- Vepoloxamer is a purified form of a copolymer called poloxamer 188, which selectively adheres to hydrophobic (water repelling) portions of cells and molecules, creating a barrier that inhibits other adhesive hydrophobic interactions. The net pharmacologic effects are improved blood flow, blood clot prevention (fibrinolysis) and reductions in inflammation and thrombosis (blood clotting). On a damaged cell, vepoloxamer restores membrane integrity and provides time for the cell's natural repair mechanisms to restore normal function.
- Previously: Mast completes enrollment in late-stage study of vepoloxamer in sickle cell disease (Feb. 22)
- Clarification: In March, the company stated that it expected to report top-line data in Q2. In June, it revised its forecast for the database lock to July with the data readout to follow shortly thereafter. In July, it revised the time line again to September. It attributed the delays to the "multitude of data points in the study and QC/QA procedures "taking longer than expected." [this news item was originally published on Sept. 1]