ASLAN Pharmaceuticals' lead drug candidate varlitinib (ASLAN001) did well in a combo therapy for the treatment of HER2-positive breast cancer in terms of tumor shrinkage rate, as new top-line phase 2 data show.
The Singapore-based biotech tested varlitinib, a pan-HER inhibitor, in combination with chemotherapy capecitabine, against the traditional Tykerb-capecitabine combo chemotherapy. It is aiming for application of the drug as second-line treatment for metastatic breast cancer patients progressing on Herceptin.
The 50-patient study showed that those who were receiving 400 mg varlitinib twice daily for more than a month enjoyed 36.4% tumor shrinkage at week 12, an improvement significantly greater than the Tykerb arm’s 17.8%, where patients received 1,250 mg lapatinib once daily. Varlitinib also presented higher objective response rate, or 60% vs. 46%.
“The positive results from this study continue to demonstrate the robust anti-tumor capabilities of varlitinib,” said ASLAN’s CMO Bertil Lindmark, M.D., Ph.D., in a press release (PDF). “We believe that varlitinib has great potential across tumor types, and it is the first of several novel agents that we are committed to developing to treat Asia prevalent cancers.”
The U.S. FDA granted the candidate an orphan drug designation in 2015 for combating biliary tract cancer cholangiocarcinoma. The drug is currently in a multicenter phase 2 trial for second-line treatment of that disease, and also in a phase 1/2 trial in combination with gemcitabine (Gemzar) and cisplatin (Platinol) as a first-line treatment.
The company said that it has also enrolled the first patient in Japan in another phase 1 study of the drug. The plan is to enroll up to 36 Japanese patients with biliary tract cancer, and study the safety and tolerability of varlitinib as a monotherapy and also in combination with capecitabine.
ASLAN is also collaborating with Hyundai Pharmaceutical to codevelop and commercialize the drug in Korea.
Last June, the drug secured a second FDA orphan designation in gastric cancer, the third most common cancer type in Asia, behind breast and lung cancers, according to a 2014 study in the World Journal of Gastroenterology.
Though blockbuster Herceptin has proven effective in many HER2 cancers, some tumors are driven by other members of the HER family that are not eligible for treatment with a HER2-selective agent like Herceptin, hence a significant unmet need for these patients and a market for pan-HER inhibitor varlitinib, the company said on its website.
Bristol-Myers Squibb licensed small-molecule inhibitor of RON and cMET receptor tyrosine kinases BMS777607 (ASLAN002) back from the Singapore biotech last August with $10 million in cash. New phase 1 data from a study the two biotechs collaborated on suggested potential for RON as a target for treatment of pathogenic bone loss.