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Real-World Treatment Patterns, HCRU in Patients With CML Achieving Later Lines of Therapy

January 14, 2021


Ehab Atallah, MD, Medical College of Wisconsin, Wauwatosa, discusses results from a study evaluating treatment patterns in patients with chronic myeloid leukemia (CML) achieving later lines of therapy, and estimating the associated health care resource utilization (HCRU) and costs.

These results were presented at the virtual 62nd American Society of Hematology (ASH) Annual Meeting.


Hello, everyone. This is Ehab Atallah from the Medical College of Wisconsin. Today, I'll be talking to you about our study looking at the real‑world treatment patterns and healthcare resource utilization associated costs among patients with CML receiving later lines of therapy.

As we all know, results for patients with CML are pretty outstanding now, and patients do really well. However, a small number of patients will require third‑line therapy or even sometimes fourth‑line therapy. We wanted to develop a model and look at the most recent world patterns of care and healthcare resource utilization in those patients.

Our data source was the IBM MarketScan. It's an administrative claim database that's in the US. It includes the combined claims from over 130 payers, including more than 250 million covered lives, so just a lot of data.

The data includes information on health plan enrollment, demographics, claims for medical services with diagnosis and procedure codes, and claims for pharmacy services.

Using this kind of data is good and bad. It's a strength that there's 20 years of data, a very large sample size of patients, and it follows what really happens in real‑world settings across the United States. We were able to use this data to look at the costs.

The limitations that have had when we were looking at these results is that the lab test results are not available, so all we know is that the lab was done, but we don't know what were the results. For example, we can't really tell whether a patient changed drug for toxicity or for resistance. All we can tell is the test was done, and the patient changed drug.

We also have limited commercially insured individuals, and also codes that are recorded for the reimbursement may be subject to some coding errors or data omissions.

The study design is, we looked at patients diagnosed with CML going back to 2001. That's when imatinib was approved. We required to have patients who had their first diagnosis with CML within three months, and that they started treatment for their CML soon after.

They also had to have continuous health plan enrollment for at least 12 months after their first CML diagnosis. This is just to make sure we have the full history of those patients we are including in our study

We started out with about 46,580 patients. With just these two criteria ‑‑ that they started first‑line therapy with one of the TKIs after 2001, and then within three months following the first CML diagnosis. With just these two criteria, the number came down to 3699, or close to 3700.

We then looked at how many patients were observed with specific first‑line CML chronic phase. It came down to 3234 patients. Of those patients, only 296, or 9.2% of the overall population, had received a third‑line, or more, TKI therapy.

This is the population we'll be looking at, is this group of patients who received third‑line treatment. Of those 296 patients, their median age was about 58 and about 8% were diagnosed from 2001 to 2005, 43% from 2006 to 2011, and 48.6% from 2012 till 2019. Many of them had other comorbidities. such as hypertension, diabetes, and cardiac arrhythmias.

In those patients, about 65% of them received imatinib as first‑line, and as second‑line about 49% received dasatinib, and about 30% received nilotinib as second‑line. As third‑line, about 20% received imatinib, 24% received dasatinib, and 36% received nilotinib.

83 patients received on to receive a fourth‑line therapy. Of those, 20% were imatinib, 28% were dasatinib, and the rest were distributed between nilotinib, bosutinib, and ponatinib.

We then looked at the healthcare resource utilization for these 296 patients, again, who received third‑line‑plus treatment. Of those, the annual instance rate for inpatient admissions for all cause was about 0.4, and CML‑related was about 0.4. There was really no difference between the third‑line only, and patients who received fourth‑line.

Outpatient days, or the number on average of resource utilization annually for outpatient days, with the third‑line‑plus was about 30 days and CML‑related was about 10 days. There was, again, no big difference between third‑line and patients who received fourth‑line and beyond.

The number of inpatient days for third‑line overall for the whole population was about 3.4. For the CML‑related, was about 3. Finally, the emergency visits were 1.2 for all cause, and 0.3 days for CML‑related. Again, no big differences here between the third‑line and patients who received fourth‑line‑plus.

When we then looked at the healthcare costs for these patients, here there was a little bit of a difference. When we look at the whole group, the whole 296 patients, the mean healthcare cost annually was about $18,784, and for CML‑related was about $17,000. About half of these costs, or a little less, were related to their medications.

If we separate these patients into patients who had third‑line, then we separate the patients who also had a fourth‑line, the cost for inpatient or outpatient cost increases significantly. For example, with fourth‑line, the cost was about $19,000 annually, and of those about $7000 are for inpatient admissions. The cost of drugs, whether it's third‑line or fourth‑line, remained pretty much stable around $10,000.

What this study really did, it's the very first study to look at healthcare resource utilization for this group of patients. You can see we started out with a really large number of patients and dwindled down to about 300 patients on third‑line and looking at the cost of care.

Most patients were fit for transplant, although they didn't really get a transplant. Pharmacy costs account for nearly half of the total cost burden during the third‑line. The proportion of medical costs took more importance following third‑line therapy, so on the fourth‑line therapy, the inpatient stay, etc., the costs for that increased.

Essentially what this shows that as the care proceeds for our patients and they go on later lines of therapy, the cost of care increases. It would be better if we can get our patients to a deeper remission earlier and not need to get to the third‑line, where there are increased costs and of course worse outcome for our patients.

Thank you all, and thank you for listening.

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