New Drug Combination Shows Promise for Leukemia Patients

A recent study suggests a hopeful drug combination could benefit leukemia patients who don’t respond well to traditional treatments. Researchers from Oregon Health & Science University explored this by examining samples from over 300 patients diagnosed with acute myeloid leukemia (AML).

Each year, AML affects more than 20,000 Americans, making it one of the most frequently diagnosed—and aggressive—forms of leukemia.

In their research, scientists mixed venetoclax, a common leukemia treatment, with palbociclib, a drug typically used for breast cancer. This combination exhibited significantly enhanced and sustained activity against leukemia compared to venetoclax used alone.

The findings were corroborated through analyses of human tissue samples and tests in mouse models inhabited by human leukemia cells.

Dr. Jeffrey Tyner, a cell biology professor at OHSU, emphasized, “The data indicate that this combination may be particularly beneficial for those with tumor characteristics that resist current frontline therapies.”

During initial trials, the research team tested various drug combinations without favoring any particular choice. Among all the combinations evaluated, the mix of leukemia and breast cancer medications emerged as the most promising.

“This pushed us to further investigate why it works so effectively and how it helps to overcome the resistance seen with existing treatments,” remarked Melissa Stewart, the study’s lead author.

Cells treated with venetoclax alone managed to adapt by increasing protein production. However, the addition of palbociclib successfully blocked this adaptation and hindered cancer cell survival.

“In our models, venetoclax did not improve survival at all, which was expected given the genetics involved,” explained Stewart. “Yet, with this combination, most mice lived between 11 to 12 months, and one mouse even survived until the end of the study.”

Unfortunately, as Tyner noted, “Eventually, almost everyone develops drug resistance.” This study clarifies the biological mechanisms at play in this new drug combination and paves the way for future clinical trials with actual patients.

Venetoclax, approved by the FDA in 2019, is often administered alongside azacytidine. Yet, even this combination faces nearly universal resistance.

“While this regimen has improved initial response rates and quality of life, the survival rate for AML after five years remains only about 25% to 40%. Clearly, we need to continue our research,” Tyner added.

Currently, the research team has suggested that this new drug should be evaluated in clinical trials. They admit, however, that they lack substantial data on clinical activity in AML patients aside from a few reported cases.

“The primary limitation is also the next step we intend to pursue, which is to test this new combination in clinical trials,” Tyner concluded.

The manufacturer of venetoclax has been contacted for comments regarding this research.