Health Rounds: Eligibility criteria limits minority patient access to precision cancer drugs

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By Nancy Lapid

Jan 9 (Reuters) - Hello, Health Rounds Readers! We once again return to the theme of racial inequities in U.S. healthcare, this time regarding access to newer precision cancer treatments. We also cover early data on a promising new approach to tackling the Ebola virus.

Cancer treatment criteria disadvantage minority patients

Eligibility for treatment with the latest cancer drugs is often determined by genetic mutations in tumors, criteria that leave minority patients at a disadvantage due to their under-representation in clinical trials, a new study found.

The earlier studies that identified the gene mutations, or specific cancer biomarkers, targeted by these drugs were primarily done in patients of European ancestry, researchers reported on Thursday in JAMA Oncology.

Under-representation of non-European ancestral groups in research databases and biobanks has stymied identification of biomarkers that are rare overall but common in minority groups, the researchers said.

Studying data on 59,433 cancer patients, they found significant differences between various ancestry groups in biomarker-based eligibility for treatment with precision oncology drugs, which are targeted to the DNA signature of an individual patient's tumor.

Patients with African ancestry were least likely to have the biomarkers that would make them eligible for precision oncology drugs, but those of East Asian and South Asian ancestries were also less likely to benefit from these personalized therapies, said study leader Debyani Chakravarty of Memorial Sloan Kettering Cancer Center in New York.

These genetic ancestry-based differences in biomarker-based eligibility for cancer treatments do not entirely explain the care access disparities faced by historically marginalized populations in the United States, Chakravarty said.

“Other contributors to these disparities exist, and many researchers... are actively working to identify and address them.”

New nanobody approach shows early promise against Ebola

A new method for attacking the Ebola virus using tiny antibodies derived from alpacas is showing promise in the laboratory, researchers reported in PLOS Pathogens.

The researchers developed two new Ebola virus nanobody inhibitors. Nanosota-EB1 blocks the ability of the virus to attach itself to cells, while Nanosota-EB2 targets a critical component of the virus necessary for cell entry, halting its spread.

In laboratory experiments in mice, the two nanobodies reduced the Ebola fatality rate to 16%, from 83% without treatment.

Ebola belongs to a class of viruses called filoviruses, for which there are two U.S. approved human antibody drugs - Ebanga from Ridgeback Biotherapeutics and Inmazeb from Regeneron Pharmaceuticals REGN.O.

The researchers from the University of Minnesota said nanobodies would offer advantages such as easier production, transportation, and storage and the potential for intranasal administration. They can also be rapidly adapted to target other viral variants or related viruses, the researchers added.

The study was carried out with funding from the U.S. National Institutes of Health.

(Reporting by Nancy Lapid; editing by Bill Berkrot)

((Nancy.Lapid@thomsonreuters.com))