Dive Brief:
- Aptose Biosciences said Jan. 23 that it is temporarily sidelining its lead product candidate, APTO-253, a phase 1 stage compound for acute myeloid leukemia, in order to focus its resources on developing its second product: CG’806, an oral preclinical compound for treating certain AML patients.
- Toronto-based Aptose said its decision was prompted by manufacturing delays related to the intravenous formulation of APTO-253, which the biopharma has been trying to resolve in order to advance its clinical development and partnering.
- The cancer-therapy company said it has sufficient cash-on-hand to continue to fund research and development and operations into fourth-quarter 2017.
Dive Insight:
The bottom-line: Aptose has been dealing with a clinical hold on its lead product for more than a year. In November 2015, its phase 1b trial of APTO-253 was temporarily suspended because of the report of an operational difficulty with an IV infusion pump – clogging -- at a clinical site.
In June 2016, Aptose inked a deal with a South Korean company, CrystalGenomics. The agreement gave Aptose the exclusive option to research, develop and commercialize CG’806, a potent small molecule therapeutic agent, globally, except in South Korea and China.
Thus, Aptose has two "compelling" cancer drugs, but "current resources can support the full development activities of only one at this time," according to the company’s Jan. 23 statement. "Recent advances with CG’806 have elevated this agent as having the best risk-reward profile to pursue with those resources," the company said.
Given Aptose’s encouraging work on CG’806, and the manufacturing setback for APTO-253, the company decided to “reprioritize” its corporate strategy, said William G. Rice, Aptose’s chairman, president and CEO. "While we remain confident in the viability of APTO-253 as a potential treatment for AML, we believe the greater value proposition to shareholders and patients is to focus our available resources on CG’806," he said.
As recently as Dec. 29, Aptose gave a positive update on the development of APTO-253. The biotech said it had successfully manufactured multiple batches of a new drug product formulation, including a batch that had been stable and soluble for more than six months. But Aptose said it would have to repeat production of the fourth batch — the one intended for clinical supply— "because of a correctable engineering design incompatibility during the filling process."
At that time, Aptose said it expected to provide the Food and Drug Administration with batch records and release specifications from a new batch, along with stability and sterility data, in first-quarter 2017.
In late December, Aptose also stressed its commitment to the development of APTO-253, stressing that the need to strengthen the filling process didn’t reflect upon "the drug substance or new formulation, both of which continue to perform favorably."
Aptose said it expects to report financial results for the year ended Dec. 31 on or around March 14.