A Potential New Treatment for Acute Myeloid Leukemia

Recently published clinical trial results suggest that combining an investigational antibody therapy with chemotherapy may be an effective strategy for patients with relapsed disease.

Researchers have published findings in the AACR journal Blood Cancer Discovery suggesting that an investigational antibody therapy along with chemotherapy may be effective in treating acute myeloid leukemia (AML) that has come back or resisted treatment.

Charalambos Andreadis, MD, professor of clinical medicine at the University of California, San Francisco (UCSF) and senior author of the study, and his colleagues investigated the safety and effectiveness of a monoclonal antibody called ficlatuzumab in combination with single-agent chemotherapy.

About half the patients in the study (53 percent) had a complete response to the therapy, meaning that cancer could not be detected in examined tissue samples. Among the patients who responded, the progression-free survival period was 31.2 months.

“While these results need to be validated in a larger study,” Andreadis said, “they suggest that ficlatuzumab in combination with single-agent chemotherapy may lead to better responses with less toxicity in patients with relapsed/refractory AML.”

The ficlatuzumab antibody works by binding to an extracellular molecule called the hepatocyte growth factor (HGF). This prevents a type of cell signaling and thereby interferes with the growth of tumors.

“Together, our findings suggest that targeting an extracellular factor in conjunction with existing cancer therapies could be an effective therapeutic strategy for AML treatment,” said Andreadis.

The phase I clinical trial enrolled 17 adult patients with AML that was either refractory to prior treatment or that had relapsed within 12 months of prior treatment. Patients received four doses of ficlatuzumab, administered 14 days apart, along with the chemotherapeutic cytarabine.

Nine of 17 patients had a complete response. Ten patients (eight responders and two non-responders) subsequently received stem cell transplants; six of these patients remained in remission at the most recent follow-up.

Limitations of the study include the small sample size and its single-arm design. Andreadis noted that a phase II clinical trial to evaluate ficlatuzumab plus chemotherapy has been initiated.