Targeted nanoparticles home in on myeloma and strengthen bones

Researchers in Boston have developed new drug-delivering nanoparticles that could target and kill bone cancer cells by homing in on calcium. And besides showing in mouse models to slow myeloma growth and prolong survival, the treatment also enhanced bone strength and volume.

According to a study in the Proceedings of the National Academy of Sciences, bone is a microenvironment that provides a destination for metastatic cancer cells and can be difficult to treat due to drug availability and resistance, researchers from the Dana-Farber Cancer Institute and Brigham and Women's Hospital wrote. To offset these challenges, the team created "bone-homing polymeric nanoparticles" designed to concentrate in the bone while carrying the cancer drug bortezomib.

The biodegradable polymers contain the osteoporosis drug alendronate, which is a bisphosphonate that binds to calcium. Naturally, because bones have such large amounts of calcium as compared to the rest of the body, the drugs accumulate there. When combined with bortezomib, this is a promising treatment for diseases like multiple myeloma.

And in mouse models of multiple myeloma, the drug-loaded nanoparticles prolonged survival and also demonstrated a bone-strengthening capacity that could offer a pre-treatment regimen for the disease, according to a report from Dana-Farber.

Irene Ghobrial

"This study provides the proof-of-concept that targeting the bone marrow niche can prevent or delay bone metastasis," senior author Irene Ghobrial said in a statement. "This work will pave the way for the development of innovative clinical trials in patients with myeloma to prevent progression from early precursor stages or in patients with breast, prostate or lung cancer who are at high risk to develop bone metastasis."

And fellow senior author Omid Farokhzid said: "These findings suggest that bone-targeted nanoparticle anti-cancer therapies offer a novel way to deliver a concentrated amount of drug in a controlled and target-specific manner to prevent tumor progression in multiple myeloma. This approach may prove useful in treatment of incidence of bone metastasis, common to 60% to 80% of cancer patients and for treatment of early stages of multiple myeloma."

- here's the Dana-Farber Cancer Institute report
- and here's the PNAS study