JCO Editorial Fellow Peter Li and author Dr. Jahanzaib Khwaja discuss the ASH 2025 Simultaneous Publication article, "A New Validated Staging System for AL Amyloidosis With Stage lllC Defining Ultra-Poor Risk: AL International Staging System."

TRANSCRIPT

The disclosures for guests on this podcast can be found in the show notes.

Dr. Peter Li: Welcome to this episode of JCO Article Insights. I am Dr. Peter Li, JCO's Editorial Fellow, and today, I am joined by Dr. Jahanzaib Khwaja on a new validated staging system on AL amyloidosis with stage lllC defining ultra-poor risk, AL International Staging System. This is a simultaneous publication that will be presented at this year's ASH Conference.

At the time of this recording, our guest has disclosures that will be linked in the transcript.

So, Dr. Khwaja, let's start off first: What would you say is the significance of your study?

Dr. Jahanzaib Khwaja: Thank you very much. This is an important study in that, in the current treatment era, we have really improved outcomes of patients with systemic AL amyloidosis. Traditionally, the staging systems that have been employed, which are the Mayo 2012 and the European modification 2016, have been founded in eras where there were historic treatment protocols.

So the significance of this new staging system is looking at outcomes of patients in the modern treatment era. That is patients who are treated with daratumumab-based treatments in the first line. And this is kind of the largest study which is externally validating a new prognostic model in the current treatment era with modern outcomes.

Dr. Peter Li: Can you tell our listeners what is different about your new staging system?

Dr. Jahanzaib Khwaja: The traditional staging systems, the Mayo 2012 and the European modification of 2016, looked at outcomes of patients with systemic AL amyloidosis with historic treatment protocols. And we know that they looked at outcomes according to an NT-proBNP and troponin, and in the Mayo 2012, they looked at it with the addition of the dFLC, which is the difference in the involved and uninvolved free light chain.

Over the years, we have seen that outcomes have improved, and over decades, actually, outcomes are much better when we compare them to the previous decade. If we look at current treatment approaches, those traditional staging systems inadequately determine the poorest prognostic risk. So they are unable to tell us those who are going to perform poorly.

Our current new validated staging system looks at the traditional NT-proBNP and troponin but uses the addition of the longitudinal strain. This is an echocardiographic parameter, and it is used widely in treatment centers who treat amyloidosis. This really identifies those ultra-high risk patients, and these are the patients who will perform poorly in current treatment protocols.

And why is that important? Well, we need a robust staging system in the current treatment era which can stratify patients who will do well but also stratify those patients who do not do well. Because that is important for counseling patients, for risk stratification, for treatment approaches, and in the future, for designing clinical trials.

Dr. Peter Li: And that is referring to the longitudinal strain greater than -9% and NT-proBNP greater than 8,500 and then the high-sensitivity troponins greater than 50, which will define the new staging system. Can you talk more about how you picked these cutoffs and also what that alludes to in terms of the outcomes that you have discovered in this age of daratumumab-based therapy?

Dr. Jahanzaib Khwaja: Yeah, that is a really excellent question because we have aimed to build upon traditional staging systems. So clinicians have used these traditional models for many, many years, and they have robustly underpinned our stratification of patients and how we counsel patients. So we didn't want to change some of these well-established thresholds, but we wanted to test them in the current treatment era. So the NT-proBNP of 8,500 and the high-sensitivity troponin of 50 were the traditionally used thresholds. And they actually stand the test of time.

But we found that longitudinal strain additionally and independently predicts outcome independent of these other biomarkers. It is independent actually as a continuous variable, so you can cut this at a number of different stratification points and find independence. But we wanted to determine and discriminate those with the poorest outcomes. So we validated a longitudinal strain threshold of greater than -9% by deriving this from a dataset of patients with the traditionally highest risk. Those are with European stage lllB. And looked at the optimal threshold with time-dependent ROC analysis.

So we did this in our derivation cohort and then validated this externally in our external validation cohort amongst a number of centers in Europe, in the US, and in the UK. And it is important to note because longitudinal strain is an echocardiographic parameter, and traditionally the limitations are considered to be inter-vendor and inter-operator variability and intra-operator variability, and there are challenges with reproducibility of some of these measurements. So that is often cited as a limitation. But we found, when we have externally validated this across different centers using different platforms, actually the threshold of -9% is independently predictive of poorer outcomes independent of the traditional NT-proBNP and troponin thresholds, and it is robustly predictive of poorest outcomes.

We know that those with stage lllC have a median overall survival of 4 to 7 months in the modern treatment era. And if we sub-stratify these by patients treated with daratumumab, outcomes have improved, but still, even if we look at daratumumab-treated patients, one-year overall survival is still only around 50 percent. So these are a poor risk group in the modern treatment era.

Dr. Peter Li: Which kind of makes sense in a way because this kind of predicts whether they have amyloid-related cardiomyopathy. So I think this all tracks with our listeners. But given the poor outcomes even with daratumumab-based therapies, do you think this new staging system would change practice, if at all?

Dr. Jahanzaib Khwaja: Yeah, I think that is a really good point because I think it comes to the question of why we use a staging system. What are its applications? I think one of the key things we think about in the clinic is how do we counsel patients when we first talk to them about their diagnosis. So there is a lot of information, but predominantly people want to know, what is my outlook going to look like?

And as I say, in the bortezomib treatment era, 2010 to 2020, we used to say you have stage lllB, you have very poor outcomes, median survival maybe around six months. We have shown here that actually those with lllB have much better outcomes definitely over 12 months, up to 24 months in those with daratumumab-based therapies. So we need to counsel them in a different way.

We then also need to say, "Well, who are the ultra-high risk?" So we said those with the longitudinal strain of greater than -9% with the traditional NT-proBNP and troponin cutoffs. And those patients will have poor outcomes. We need to talk about palliation. We need to talk about alternate treatment approaches.

And then importantly for the community is about treatment and clinical trial design. So again, traditionally the traditional high-risk group lllB used to be considered an exclusion for all major trials. So these were excluded in the ANDROMEDA study, which led to the approval of daratumumab-based therapy, and multiple other trials. And we show here that actually patients with lllB should not be excluded from these studies because they do have good outcomes.

And I think we make the important point that those with lllC, who do have poor outcomes, they need a different treatment approach, and we need to think about stratifying these patients differently. So perhaps the next modality of treatment will be the anti-fibril antibodies or a mode of treatment which can clear antibodies or clear the amyloid fibrils from the organs and reduce the organ toxicity early on.

We know that those with lllC have poor outcomes particularly within the first year, and organ dysfunction really predominates here. So a different treatment approach is required, and we need to design trials specifically for these patients which look beyond anti-plasma cell clone therapy but also look at clearing the amyloid fibrils and improving organ function as this is predominantly the cause of death in these patients.

Dr. Peter Li: That's an excellent point right there.

Do you foresee any limitations to this new staging system, or can you comment on is there potentially a better way to refine this staging criteria in the future?

Dr. Jahanzaib Khwaja: Yeah, I think that is a really excellent point to consider, that staging systems always need refining across treatment eras. So we have looked at the bortezomib era, and then we have validated this in the daratumumab-based era. We know that amongst different countries access to treatment varies. We know that there are a number of factors which determine your health-related outcomes. That's access to healthcare, speed of diagnosis, access to tertiary diagnostics, ability to biopsy, and then supportive care.

And I think our staging system highlights the importance of organ dysfunction predominantly causing death early on. And I think that as treatments improve this should be refined. So the expectation I think is, as we have better anti-plasma cell directed therapies, and as we hopefully develop anti-fibril antibodies and anti-fibril clearance drugs, that we will need to revalidate new models to effectively prognosticate in this treatment era.

And I also think that as we become a bit more sophisticated with our approaches, we know that this can be refined in the future looking at other prognostic factors with regards to healthcare outcomes. I would say one of the strengths, however, of this model is that it builds on the traditional model, and it's quite simple to use. You just have the NT-proBNP and the troponin, and then longitudinal strain, which is used quite frequently in amyloid centers, and an echocardiogram is used in essentially all patients for diagnosis. So I think it will certainly be quite practical.

But certainly I think, as you say, as treatment approaches change over time, and as we have further options in the future, we will need to refine prognostication.

Dr. Peter Li: For the listeners out there, let's say someone comes in our clinic and we diagnose them with stage lllC amyloidosis. Can you comment on what clinical trials are out there that potentially they can refer their patients to? You mentioned anti-fibril therapy, which I think would be the way of the future. Can you kind of comment what you know at this current stage and point listeners in the right direction?

Dr. Jahanzaib Khwaja: This is the challenge in amyloidosis. We don't have specific trials that are looking at those with the highest risk. And at present, even the ISA International Guidelines talk about risk according to the old treatment approaches and discuss attenuating our current chemotherapy approaches. And I think that for clinicians out there who identify those at the highest risk, it is really important to have a multidisciplinary approach, to consider palliation and palliative services early, and really work with your fellow cardiologists and renal physicians and neurologists to enable the best supportive care you have in order to deliver this anti-plasma cell directed therapy.

We know that actually you only need for most patients small amounts of doses of chemotherapy to get good clonal responses, and we have seen that even in the bortezomib era that actually they have good CR rates and more impressive CR rates with daratumumab. But because of the organ dysfunction, it can be really challenging to deliver these doses. And supportive care is going to be really important particularly for these challenging patients.

The future will be designing clinical trials that are appropriate for these patients. At present, we currently don't have available options, but I think the more we gather this data, the more we work collaboratively as a community, we will be able to mobilize our resources and get the best outcomes for these patients.

Dr. Peter Li: First build the field of dreams and then hopefully more therapies will arrive in the future.

Thank you so much, Dr. Khwaja, for speaking about the JCO article, "A New Validated Staging System for AL Amyloidosis With Stage lllC Defining Ultra-Poor Risk: AL International Staging System," and for all your valuable input today.

Dr. Jahanzaib Khwaja: Thank you very much.

Dr. Peter Li: Make sure to check out the presentation at this year's ASH Conference taking place from December 6 to December 9. Thank you for listening to JCO Article Insights. Please come back for more interviews and article summaries and be sure to leave us a rating and review so others can find our show. For more podcasts and episodes from ASCO, please visit asco.org/podcast.

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