What happened

Shares of TG Therapeutics (TGTX -0.30%) rose 59.9% this week, according to data from S&P Global Market Intelligence. The biopharmaceutical company closed last week at $5.84, which is precisely where it opened this week.

Its big rise came on Thursday, Nov. 10, when the stock rose 63.37% in one day. On Friday, Nov. 11, it rose to a weekly high of $9.60, then closed the week at $9.34. The stock is still down more than 50% this year.

So what

The biopharma came out with big news the same day that inflation numbers came in lower; the combination helped drive the stock upward. While the company released its third-quarter report, most of the optimism surrounded the possibility of its lead therapy, ublituximab, to treat relapsing multiple sclerosis (MS).

MS is an autoimmune disease disease affecting the central nervous system; it generally attacks the brain, spinal cord, and optic nerves. Its most common form is relapsing-remitting MS, in which regular attacks of neurologic symptoms, called relapses or exacerbations, are followed by periods of remission. According to a 2019 study funded by the National Multiple Sclerosis Society, nearly 1 million people in the United States have MS.

When TG Therapeutics released its third-quarter report, the most important news in it was about ublituximab. The company said that the drug's Biologics License Application (BLA) had been accepted by the Food and Drug Administration (FDA), and a Prescription Drug User Fee Act date of Dec. 28 had been scheduled. That means TG Therapeutics will plan for the launch of its first marketed therapy, moving it from a clinical-stage to a commercial-stage biotech, as soon as next year.

Now what

The enthusiasm for the biotech stock may soon die down a bit, because it's a long way to the finish line for ublituximab. The drug, a monoclonal antibody, reduces a patient's number of B cells (also known as B lymphocytes) -- white blood cells that can trigger an outsized immune response, which may involve an attack on the myelin coating of nerves that's seen in MS patients.

There are already two other B-cell therapies to treat MS on the market, ocrelizumab and ofatumumab, so ublituximab has plenty of competition. Note that if TG Therapeutics has its BLA approved, that isn't the same thing as the therapy getting approval -- it's just one step in the regulatory process.