Christopher Kim, PhD, MPH, Center for Observational Research, Amgen, Inc., Thousand Oaks, CA, discusses findings from a study which evaluated treatment and outcomes among patients with triple-class relapsed or refractory multiple myeloma (MM) who received prior treatment with at least 1 proteasome inhibitor, immunomodulatory imides, and CD38 monoclonal antibodies in US community practice.

These findings were presented at the 2021 ASH Annual Meeting.

Transcript

Hello. My name is Christopher Kim. I'm a director in the Center for Observational Research at Amgen, and I work in the hematology therapeutic area.

Today, I'll be introducing some of the research that we've worked on in multiple myeloma with real-world data. The poster I'll be presenting is the ASH poster 3042, “Outcomes of Triple-Class Exposed Relapsed or Refractory Multiple Myeloma in the United States Real-World Practice.”

Let me introduce the topic. We conducted this study, basically, to understand what are the treatment patterns as well as the real-world outcomes of patients that have been exposed to at least 3 different classes of therapies for treatment of multiple myeloma.

These patients have been exposed to at least 1 proteasome inhibitor, 1 immunomodulatory agent, as well as a CD38 monoclonal antibody. The reason that these 3 classes of drugs are important is because they're all bedrocks of treatment of multiple myeloma.

Once patients have exhausted treatment options in those 3 classes, their treatment options have become greatly reduced. Many of the standard therapies that are available for these patients just are not ideal.

What we want to do this study was to describe the characteristics of these types of patients. These types of patients typically become available for late-line clinical trials, and we want to describe what their outcomes were. Their outcomes were real-world overall response rate, real-world progression-free survival, and real-world overall survival.

To conduct the study, we used the Flatiron Enhanced Data Mart, which is unstructured data processing on standard EHR records that is curated by Flatiron, and then it additionally abstracts a number of myeloma-specific variables to really characterize this population.

This dataset really is representative of a large number of community and some academic clinics in the United States. The types of patients we wanted to evaluate for this particular study were those that would be most similar to those types of patients that will be eligible for clinical trials. We had a number of inclusion/exclusion criteria that mimic what most clinical trials would be looking at.

I mentioned that the patients included in this study, we want to look at the treatment patterns. We get a requirement for them to have exposure to all these drugs by November 2015, which is the first date of approval for daratumumab in United States, and study entry could occur through December 2019. We didn't follow up for at least a year through December 2020.

In the study overall, we included roughly 120 patients. They were mostly male. They were older, 65-plus. We have a moderate distribution of high-risk vs standard-risk patients.

The majority of patients were fifth-line plus at the time of being eligible to be included in the study, and the majority of the patients were also triple-class refractory, meaning that they had some disease progression within 30 days of last drug exposure.

In addition, about 20% of the patients were penta-refractory, meaning that they had been refractory to bortezomib, carfilzomib, lenalidomide, pomalidomide, as well as daratumumab.

When we started evaluating what types of regimens that these patients received, the vast majority of patients were receiving a triplet type of combination, but what we also noted was that patients did not receive any particular regimen overwhelmingly.

The most common regimen identified was daratumumab, pomalidomide, dexamethasone, but only 6% of the population had that combination. Otherwise, the types of drugs received by all patients was very scattered.

What was of real interest to us was that many patients were receiving the same drug that they already previously received suggesting that patients have run out of options and are re-receiving a drug that maybe they had already progressed on and are potentially refractory to, which is suboptimal based off of current recommendations by clinical guidelines.

Overall, patients had pretty poor outcomes. Only about 18% of patients had a response of partial response or better by ORR. We noted that the median progression-free survival for patients in this population was 3.5 months. The overall survival for the patients surprisingly was actually quite a bit longer than the progression-free survival might suggest at 15.8 months.

We also did a few additional subgroup analyses. In particular, the patients that were penta-refractory, their progression-free survival was 2.1 months. The overall survival for the penta-refractory patients was 7.1 months suggesting that the more refractory patient is the worse overall outcomes that these patients have.

Overall, what we found out from this study was that patients for the most part are re-receiving drugs that they have previously received. They have relatively short progression-free survival, but that they had relatively moderate overall survival compared to some other previously published literature.

What this indicates is that there's been many new drugs that have been approved for usages in myeloma since the pivotal paper released in 2019, the Gandhi et al paper, which is the MAMMOTH study, that additional survival seems to be significant compared to what was published there. Maybe, we can think of the new drugs approved since then to account for that change in survival.

Kim C, Braunlin M, Mehta B, et al. Outcomes of Triple-Class (proteasome inhibitor, immunomodulator, CD38 monoclonal antibody) Exposed Relapsed or Refractory Multiple Myeloma (RRMM) in United States (US) Real-World Practice. Presented at the ASH Annual Meeting and Exposition; December 11-14, 2021; Atlanta, GA and Virtual. Abstract 3042.