Aslan Pharmaceuticals, a biotech company focused on the development of immunotherapies and targeted agents for Asia prevalent tumour types, has announced positive phase 2 results for its lead drug candidate varlitinib (ASLAN001) in combination with capecitabine as second-line treatment for metastatic HER2-positive breast cancer patients progressing on trastuzumab (Herceptin). Varlitinib is a reversible potent small molecule inhibitor of the HER-family of receptor tyrosine kinases (RTKs).
The multinational, randomised open-label study compared the effects of varlitinib combined with capecitabine versus that of lapatinib (Tykerb) combined with capecitabine on tumour shrinkage at week 12. Top-line data showed significantly greater tumour shrinkage at week 12 of the treatment cycle in patients who were on therapy for more than a month, receiving 400 mg varlitinib (36.4%) twice daily compared to 1,250 mg lapatinib (17.8%) once daily (p=0.075). A total of 50 patients were enrolled in the study.
While the study was not powered for objective response rate (ORR), it found that patients dosed with varlitinib showed higher ORR compared to patients on lapatinib (60% versus 46%). There were no differences in progression-free survival (PFS) or overall survival (OS) in the study. Adverse events reported included nausea, vomiting and diarrhoea, and occurred at similar frequency in both arms. The incidence of grade 3 diarrhoea was 12.5% in the varlitinib group and was clinically manageable. There were no instances of grade 4 diarrhoea. No anti-diarrhoea prophylaxis was mandated for patients in the varlitinib group.
"The positive results from this study continue to demonstrate the robust anti-tumour capabilities of varlitinib,” said Dr Bertil Lindmark, chief medical officer, Aslan Pharmaceuticals. “We believe that varlitinib has great potential "The positive results from this study continue to demonstrate the robust anti-tumour capabilities of varlitinib,” said Dr Bertil Lindmark, chief medical officer, Aslan Pharmaceuticals. “We believe that varlitinib has great potential across tumour types, and it is the first of several novel agents that we are committed to developing to treat Asia prevalent cancers.”
Varlitinib is also being developed in other indications, including gastric and biliary tract cancers.