Tagrisso Response Duration - 1293714

Hi bfarz,

Congratulations on the great response to Tarceva, and I hope your scan results show that Tagrisso has been effective. As with Tarceva and many other lung cancer drugs, there are cases of patients responding for a number of years, to the point where these patients "drop off" the statistics due to a lack of continued follow-up. Since Tagrisso is relatively new, that is certainly the case, and I hope that you become one of these "outlier" patients for whom the response is particularly durable.

As discussed in Dr. West's post on lepidic predominant adenocarcinoma (still often referred to as "BAC"), this type of lung cancer can be aggressive, but it can also be "very slow growing and among the least threatening cases ever labeled as lung cancer." At diagnosis, it's not possible to determine how aggressive a particular patient's cancer will be, but the passage of time helps answer that question. From the history you've described, your cancer appears to be slow-growing and responsive to Tarceva, so it may be that you will have a long response to Tagrisso as well.

At present, progression on second-line Tagrisso is treated with standard chemo agents or perhaps immunotherapy, as we don't really have a good TKI to address such progression. Also, as you mention, some oncologists, in the face of a single site of progression, will radiate that site and continue the TKI.

As far as a biopsy to check for a new mutation, if there isn't progression of sufficient size to biopsy, then there may not be a need to change therapy. And since there is no Tagrisso resistance mutation for which we have a targeted therapy, a biopsy may not provide usable information. That being said, if at some point your doctor feels a biopsy is needed, then a liquid biopsy (using bodily fluids rather than tissue) may be recommended.

But we're hoping Tagrisso is effective for a long time!

JimC
Forum moderator

Hi bfarz,

Dr. West has stated that most cases of BAC are not pure BAC but a mixture of BAC and a more invasive form of adenocarcinoma, sometimes referred to as "adenocarcinoma with BAC features". Such cancers can be indolent as well. As Dr. West stated in the comments to this post:

"Adenocarcinoma with BAC features is a mix, and it can act more like a classic BAC syndrome and grow slowly in the chest only, or it can have a bit of BAC but really act like a regular invasive NSCLC (adenocarcinoma). Conventional chemo tends to work best on faster growing cancers, so I believe that some of the problem with less responsive BAC tumors is that they are so indolent that they aren’t very vulnerable to chemo. However, adeno with BAC features can be as aggressive as any other NSCLC, or pretty slow. Often how the patient is doing over time (one month to the next, for instance) and/or how much scans have changed, especially in between treatments, can give a hint."

There is research into fourth generation EGFR TKIs, but I haven't located any open trials at clinicaltrials.gov. One such agent is EAI045, for which I found no pending trials.

JimC
Forum moderator

Hi bfarz,

Congratulations on the great scan report; glad that you can stick with Tagrisso and that it continues to keep your cancer under control.

If you have a mixture of indolent BAC and adenocarcinoma, there is always the possibility that the invasive component can become more aggressive, although your long history of slow/no growth makes that less likely. With any slow-growing cancer, it can be difficult to determine whether it's the treatment that's working well, or just the indolent nature of the cancer.

JimC
Forum moderator

Hi Bfarz!

Glad to hear the Tagrisso is working. Hope you continue to have great response and control from it!

Just a note on 4th generation TKIs. There actually is an ongoing trial of a new TKI designed to treat the most common resistant mutations ( i.e. Exon 20 mutations) from EGFR as well as the Exon 20 mutation of HER2. It even has a test cohort of patients with more typical Exon 19/21 mutations. It is clinical trial of a drug AP32788 (originally from Ariad Pharmaceuticals, bought out by Takeda). The clinical trial number is NCT02716116. They are currently recruiting and I believe they have just entered their expansion phase (I believed they have completed their dose determination phase) and will be beginning to accept patients at new sites. This is the trial my wife is approved for, but they are holding off for now since she is responding well to gemcitibine.

All the best to you for continued great control from Tagrisso!

scohn