MCL - BTK Inhibitor Second Line Therapy

MCL - BTK Inhibitor Second Line Therapy
Purple flower in acrylic. Feeling hopeful.

(Originally published April 18, 2022)

It's official - we are moving from first line (the Rituximab + chemotherapy drugs) to second line therapy.

I have a much better shot at getting relief with the new drug, Zanubrutinib.

Zanubrutinib is a BTK (Bruton Tyrosine Kinase) Inhibitor.  Mantle Cell Lymphoma is a B-Cell Lymphoma. The rough idea behind the BTK Inhibitors is that they interrupt the signaling that causes malignant B-Cells to multiply. has a nice summary of how these drugs work to knock down B-Cell Lymphomas.

Zanubrutinib (brand name Brukinsa) is a BTK Inhibitor that has been specifically approved for Mantle Cell Lymphoma.

3 things excite me about this new treatment plan:

  1. I'm taking pills daily vs. sitting in a treatment chair for days
  2. The drug action is more targeted.  Though it isn't without side-effects and I'm not sure how well I'm going to tolerate it, there will be less collateral damage of healthy cells.  I vaguely remember one of the doctors telling me that the Zanubrutinib is also one of the more successful therapies for the TP53 mutation I likely have.
  3. I've "failed" the first line therapy very quickly to get here, so I managed to save most of my hair (it's thinner, but nothing anyone would notice) + not beat up my body needlessly.  I'll admit, I was dreading treatment session #2 and another round with the Rituximab.

As one of my Mom's retired nursing friends put it to her - "It's a good thing she failed the treatments early.  It would have been more difficult if she went through 3-4 cycles to then have the treatment fail on her."

I should be receiving a package with the pills Monday (the day this posts).

Because this is a very new and highly specialized drug, I have to get my drugs through a specialty pharmacy vs. the local CVS. This is the specialty pharmacy vetted through my insurance.

I'm very fortunate that my oncologist is willing to work with me to address any issues with the insurance company and (recently) with the local pharmacy.  And, to Cigna's credit, they have also been working very quickly on my behalf with approvals and raising potential issues with both me and the oncologist.

Overall, I'm doing OK. Still independent and ambulatory. As long as I don't over-extend myself with too many trips up and down the stairs or walks that are too long, I feel decent.  When I over-extend myself, my spleen starts to act up. Unfortunately, the line between "good exercise" and "overextension" is really thin.  Some days, what used to be the "short" dog walk is too long.

I don't know whether this will prove to be a miracle drug that shrinks the spleen and allows me to at least get back to something resembling a yoga practice and, possibly, get large chunks of my old life back over the next couple of years.

More likely, this will help knock down some of the cancer, shrink the spleen a bit where it is not so uncomfortable, helps my body create its own blood again, and buy me 6-24 months without further progression.  I am well aware this is not a long-term solution and will not cure me.  It will be a bonus if this medication puts me in full remission.

As part of this process, the oncologist and I will also start putting together information for CAR-T Therapy.  I have already identified the local hospitals eligible to perform this treatment and managed to (roughly) determine which of these hospitals are in-network.

I will also be taking another look-see at some of the clinical trials.  Now that I have failed the first-line standard chemotherapy treatment, I have more options if I decide to go the clinical trial route.  The one consideration I need to make is whether I am quantitatively healthy enough to participate.  With my blood numbers being as unstable as they have been, acceptance to any of these trials right now is far from guaranteed.

On the good news front: I managed to avoid a blood transfusion last week.  My hemoglobin numbers managed to stay around 8 - low ("normal" starts around 11), but not requiring a transfusion.

Next blood test and doctor's appointment is on Thursday. We'll see whether we can avoid a blood transfusion this Friday.

Wish me luck with the new pills. I start taking them as soon as they get here.