- The New York-based biotechnology company TG Therapeutics has decided to pull its only approved medicine from the market, after recent clinical trial data showed a potentially increased risk of death in cancer patients who received the drug in combination with one of TG's experimental therapies.
- The Food and Drug Administration first cleared TG's Ukoniq in February 2021 as a treatment for two types of lymphoma. The agency issued a so-called accelerated approval, which allowed TG to sell the medicine while simultaneously running studies to confirm the benefits seen in earlier testing. Much of the company's work has focused on developing Ukoniq in combination with another drug, ublituximab, a pairing nicknamed U2.
- One month after Ukoniq's approval, TG asked the FDA to greenlight U2 for the treatment of two other blood cancers. While the agency accepted TG's application, it became concerned about survival data generated in the key study meant to support U2's approval. TG said Friday that, in light of these data, the company has withdrawn its U2 application and, subsequently, will stop selling Ukoniq.
The process of advancing a drug through the various stages of research, clearing it with regulators and bringing it to market takes years, if not decades.
But in diseases like cancer that are deadly, fast-progressing or both, patients typically can't wait that long. So to help get new treatments for serious illnesses to patients faster, the FDA has for the past 30 years been allowed to issue accelerated approvals, which are often based on much smaller amounts of evidence and surrogate measures of patient health.
Though it has ushered effective therapies to market, the accelerated approval pathway has also come under fire. In some cases, the trials meant to confirm these drugs work as intended were never completed, or produced negative results. In theory, that would warrant drugs getting pulled from the market. But such an outcome is relatively rare. Looking at cancer specifically, just 6% of accelerated drug approvals have been withdrawn as of March 2021.
Top government officials are now taking a closer look at accelerated approvals. The U.S. health department's inspector general, for example, opened an investigation into the accelerated approval process, after the FDA chose to clear a controversial treatment for Alzhiemer's disease.
On its end, the FDA convened a group of outside experts last spring to review six speedy approvals granted to cancer immunotherapies from Bristol Myers Squibb, Roche and Merck & Co. The experts ultimately recommended the agency leave four of the six approvals in place.
Advisers to the FDA are set to meet again this week, to discuss the "appropriate approach" for using the class of drugs that includes Ukoniq to treat blood cancers. The TG drug is known as a PI3K inhibitor, meaning it blocks the activity of an enzyme called phosphatidylinositol-3-kinase, which is tied to many types of cancer.
Having chosen to withdraw both Ukoniq and the U2 application, TG said the portion of the meeting set to discuss its drugs will be canceled.
CEO Michael Weiss added that, moving forward, the company will focus on developing drugs for multiple sclerosis and autoimmune diseases. Already, it has submitted to the FDA an approval application for ublituximab in relapsing forms of multiple sclerosis, and expects a decision from the agency by Sept. 28.
Shares of TG opened at $6.03 Monday morning, down nearly 32% from where they closed on Thursday.
TG isn't alone in pulling products and approval applications. Early this year, Gilead voluntarily withdrew its drug Zydelig from the treatment markets for relapsed follicular B-cell non-Hodgkin lymphoma and relapsed small lymphocytic leukemia. The FDA granted Zydelig accelerated approvals in those diseases in 2014. But due to a changing treatment landscape and challenges enrolling confirmatory studies, Gilead opted to drop the indications.
Similarly, Incyte decided to drop an application for its experimental lymphoma medicine after concluding that confirmatory studies wouldn't be worth the investment.