Aldoxorubicin Improves PFS in Some Relapsed/Refractory Sarcomas

Aldoxorubicin yielded significantly better progression-free survival (PFS) over investigator’s choice of various chemotherapy options in patients with relapsed or refractory leiomyosarcoma and liposarcoma, according to updated results of a phase III trial.

“This data represents a major step forward for soft-tissue sarcomas [STS], a rare, highly complex and very difficult to treat group of cancers,” said study lead investigator Sant Chawla, MD, of the Sarcoma Oncology Center in Santa Monica California, in a press release.

The trial, a phase III randomized study, included a total of 433 patients with STS. Patients received either aldoxorubicin, which combines doxorubicin with a novel linker molecule that binds to circulating albumin, or investigator’s choice of gemcitabine plus docetaxel, or dacarbazine, pazopanib, doxorubicin, or ifosfamide.

Among the 246 patients with leiomyosarcoma or liposarcoma, the study drug resulted in a significantly improved PFS, with a hazard ratio (HR) for progression of 0.62 (95% CI, 0.44–0.88; P = .007). For the full study population, there was a trend toward better PFS with aldoxorubicin, with an HR of 0.81 (95% CI, 0.64–1.06; P = 0.12). There was also a significantly better PFS specifically among the 312 patients treated in North America, with an HR of 0.71 (95% CI, 0.53–0.97; P = .028).

The company that manufactures the drug, CytRx, reports they will likely submit a New Drug Application for aldoxorubicin to the US Food and Drug Administration in 2017, specifically for the treatment of patients with relapsed or refractory STS.

The disease control rate (defined as objective response or stable disease for at least 4 months) was significantly better with aldoxorubicin in the full 433-patient cohort, at 29.4% vs 20.5% with investigator’s choice (P = .030). The benefit was again more pronounced in North American patients, with a control rate of 32.9% with aldoxorubicin compared with 19.2% (P = .007). The objective response rate was 8.7% in North American patients, compared with 3.3% with investigator’s choice (P = .058).

The study is ongoing, with overall survival data likely to be reported in 2017. The most common adverse events included neutropenia and anemia in the full study population; 61% of aldoxorubicin patients and 46% of investigator’s choice patients experienced a grade 3 or higher adverse event. Treatment-emergent adverse events that led to therapy discontinuation occurred in 4.2% of aldoxorubicin patients and in 6.3% of investigator’s choice patients.