FDA Priority Review for Obinutuzumab

The FDA announced today that  it will grant Priority Review for Obinutuzumab for patients with untreated Follicular Lymphoma. It's good news.

Let's break this down.

First, "Priority Review" is one of the categories that the FDA (which approved cancer treatments and other things in the United States) developed to try to speed up approvals. A Priority Review is given for a treatment that make provide a significant improvement over what is already available, and it means that a decision will be made within 6 months. For Obinutuzumab (also known as Gazyva), the approval should come before the end of the year.

So what is Obinutuzumab improving on? Why, Our Old Pal Rituxan. They are both Monoclonal Antibodies (which is why "mab" is at the end of the name, like it's at the end of the name Rituxumab and the beginning of Mabthera -- other names for Rituxan).

Like Rituxan, Obinutuzumab targets the CD20 protein on B Lymphocytes (the white blood cells that cause Follicular Lymphoma). What makes it different is that it is humanized (Rituxan was developed from mouse cells) and in theory, that should cut down on some of the allergic reactions that people have to Rituxan (like the one I experienced).

Obinutuzumab is also glycoengineered. That means that sugar molecules are added to them in a way that makes them better at their job (which is to call out to the immune system to attack the cancer cells). The company that makes Obinutuzumab has a cute video that explains it all.

The FDA granted Priority Review based on the results of the GALLIUM trial, which compared Obinutuzumab + chemotherapy with Obinutuzumab maintenance to Rituxan + chemotherapy with Rituxan maintenance. In the trial, after 41 months, the Obinutuzumab patients had a 32% less chance of the disease getting worse.

It will be interesting to see what happens. I think there's a good chance that Obinutuzumab gets approved after the review. (Obinutuzumab is already approved for Follicular Lymphoma as a second line treatment -- for use by people who had taken Rituxan, but had it stop working within 6 months.)

I'm curious what happens after that. Will oncologists start using it in place of Rituxan? There are going to be a bunch of choices in that area soon -- biosimilars might be used in place of Rituxan, too. I have no idea where Obinutuzumab comes in as far as cost goes, and if the cost will make it worth choosing it over Rituxan, even if Obinutuzumab might work slightly better. old habits die hard -- lots of oncologists still go with CHOP, just because that's what they've always done.

As always, it's going to come down to an honest discussion with your doctor.

The important thing, though, is that we might have another choice when it comes to treatment.  And that's good news.