VBL Therapeutics shares (NASDAQ:VBLT) plummeted 65.5 percent Tuesday to $4.87, more than a dollar under the company's recent initial public offering (IPO) price, as investors digested news that VB-201, an experimental autoimmune therapy that had appeared to help patients with psoriasis in an earlier midstage study, failed to significantly benefit both psoriasis and ulcerative colitis sufferers in separate phase II trials.