ASCO: 5F9 Follow-Up

The abstracts for the ASCO meeting are out, and the Follicular Lymphoma abstracts are available here.

The ASCO meeting (ASCO stands for American Society of Clinical Oncology) is one of the two big meetings that I follow every year. The other one is ASH (American Society of Hematology). They occur about 6 months apart. There are lots of other big meetings where researchers present their findings about blood cancer, but these two often have good stuff to get excited about.

I don't go to the meetings, which would be a different experience -- hearing questions and follow-ups, and maybe getting more up-to-date data -- but reading the abstracts, which summarize the research being presented, is usually enough to get a sense of what's exciting.

That's especially true when Lymphoma experts get on Twitter and YouTube in the days right after the meeting and talk about what excited them. I always get a thrill out of hearing experts get excited about things.

In my last post, I talked about the FDA Fast Tracking a new treatment called 5F9, which targets the CD47 protein on the surface of cells. The press release for the Fast Tracking said that data would be released soon -- I took a guess and figured it would be released at ASCO.

Sure enough, that's it. I still haven't had a chance to explore the ASCO abstracts, so thanks to William for leaving a link to the abstract in the comments of my last post. (He also emailed me a link to the abstract for the CAR-T trial that his wife has been very successfully involved in -- look for that soon.)

The ASCO session for 5F9 is called "Activity and tolerabilty of the first-in-class anti-CD47 antibody Hu5F9-G4 with rituximab tolerated in relapsed/refractory non-Hodgkin lymphoma: Initial phase 1b/2 results."

The presentation looks at results from a phase 1b/phase 2 clinical trial. Phase 1 trials usually focus on safety -- figuring out how much of a treatment to give to a patient to be safe but still effective. [We should all thank those folks in phase 1 trials who are willing to be tested this way.]

Phase 2 looks at efficacy -- how well the treatment does, compared to other accepted treatments -- on a small group of patients. If the phase 2 results show that it's effective, the phase 3 trial will involve a larger group of patients. [While we're at it, let's thank those in phase 2 and 3 trials, too.]

So the 5F9 trial looks at safety and efficacy -- phase 1b and 2. Patients involved had Diffuse Large B Cell Lymphoma (15 patients) and Follicular Lymphoma (7 patients). 22 total is a very small number for a trial, so keep that in mind.

Patients were "heavily pre-treated" and refractory or resistant to Rituxan -- the median number of treatments before  this trial was 4, and Rituxan wasn't working anymore. The patients were given 5F9 and Rituxan (even though it wasn't working, the combination with 5F9 might work differently).

Results were good -- overall, no matter the type of Lymphoma or the dose given, there was a 50% Overall Response, with a 32% Complete Response. For the 7 FL patients, 5 had a response (71%), with 3 having a Complete Response (43%). In the whole trial, 90% of patients who had a response continued that response, with a median of 4.4 months, and one going for over 13 months.


As for safety, the side effects were manageable. Anemia (low red blood cells) was a particular concern, but they seemed to be able to control it. (CD47 is a self-marker for red blood cells, so 5F9 would probably target them the way it would with a cancer cell.)

So, good results -- good enough for the FDA to fast Track this treatment. As I said last time, Fast tracking doesn't mean it will necessarily get a review anytime soon, but it does mean that the FDA recognizes that there is a need that this treatment might fill, and it will give it some extra help to get to the approval stage.

I'll say it again -- while it's promising, it's also really early. 22 patients (and only 7 for FL) isn't going to really tell us how well this works. But the phase 2 trial is ongoing (info is here) so we'll get more answers in time.

I have a couple of posts planned before I get to the ASCO stuff, so stay tuned. Lots going on in the world of Follicular Lymphoma these days.