FDA Grants Marginal Zone Lymphoma Drug a Breakthrough Designation

According to a publication from OncLive, the FDA has granted TG Therapeutics’ experimental marginal zone lymphoma drug Umbralisib a “Breakthrough Therapy” designation.

About Marginal Zone Lymphoma

Marginal zone lymphoma (or MZL) is the third most common type of B-cell non-Hodgkin lymphoma. This group of cancers affects the body’s lymphatic system, an important part of the overall immune system.

There are three kinds of marginal zone lymphoma. They are:

  • Mucosal-associated lymphoid tissue (MALT) – the most common form of MZL, accounting for about 67% of cases in a given year. This type occurs outside the body’s lymph nodes, most commonly in the stomach.
  • Splenic MZL (SMZL) – the second most common form of MZL, comprising about 20% of annual cases. You may have guessed it, but this type occurs primarily in the spleen and bloodstream.
  • Nodal MZL (NMZL) – the rarest of the bunch, comprising only 10% of MZL cases each year. In this type, the lymphoma occurs within the lymph nodes themselves.

These types vary in their prognosis, treatment, and likely outcomes. All of them are potentially fatal, though the associated five-year survival rates range between almost 89% (MALT) and 76% (NMZL).

Breakthrough Therapy and The Phase 2 Trial

TG Therapeutics’ ongoing phase 2 trial for Umbralisib yielded some impressive data in one cohort (group of subjects). In fact the data was so impressive that the FDA granted Umbralisib a breakthrough therapy designation.

A breakthrough therapy is a treatment that early evidence suggests provides a significant improvement on existing treatments. The designation is designed to help speed up the development and review of drugs that could potentially benefit a lot of people.

The ongoing phase 2 trial is attempting to ascertain Umbralisib’s effectiveness in combating a number of Non-Hodgkin lymphoma (NHL) types. Depending on the type of NHL being treated, Umbralisib is being administered either strait, or as a doublet or triplet (being one-half or one-third, respectively, of an administered drug cocktail).

The triplet, for example, has in phase 1 and 2 trials elicited a 90% response rate in patients with recurring chronic lymphocytic leukemia (CLL). The same triplet also elicited a 50% response rate in patients with Richter’s transformation. Scientists are still trying to work out the most effective uses for the drug, which will hopefully become clear as phase 2 and 3 trials eventually conclude.

The FDA’s breakthrough therapy designation for Umbralisib is really encouraging, and patients with many different types of lymphoma might hopefully one day be treated with the drug. The expedited pace that comes with breakthrough status means we could possibly see definitive results (and maybe even approval!) within the next couple years.


Breakthrough therapy designation is designed to help expedite the drug development and review process. Do you think breakthrough status is a good indicator that a drug will eventually be FDA-approved? Share your thoughts with Patient Worthy!

Share this post

Share on facebook
Share on google
Share on twitter
Share on linkedin
Share on pinterest
Share on print
Share on email