Context Therapeutics, a three-year-old University City firm set up to develop new cancer-fighting drugs, has bought Apristor, the last drug owned by Arno Therapeutics, a Flemington, N.J., drug company that is dissolving.

Arno tried to develop the drug for prostate cancer. Context plans to develop Apristor as a breast cancer treatment and hopes it will become its first revenue-producing drug.

Apristor offers a "novel treatment" for metastatic breast cancer, which kills 40,000 American women a year, Martin Lehr, Context's chief executive, said in a statement.  The drug, which blocks the hormone progesterone, "established efficacy in two Phase 2 metastatic breast cancer clinical trials" before Arno owned it, according to Context. The drug "has been studied in over 200 patients," most of whom were previously taking the drug Tamoxifen, "and it was well-tolerated with no drug-related serious adverse events." Terms of the sale were not disclosed.

In  2016, Arno closed the prostate cancer trials using Apristor to focus on prostate cancer. Context will now shift the drug's focus to breast cancer, and said it will have "exclusive" patented use of the compound through 2034 or later.

Arno had been testing Apristor (also called Onapristone XR) for operation-resistant prostate cancer, with backing from billionaire investor George Soros and the Israel-based Pontifax venture capital group, among others. Arno went public after a 2008 merger, and investors bid its share price up to $25 that year in hopes that its portfolio of cancer-fighting drugs would prove profitable. The price slid below $1 in 2014 as Arno failed to bring products to market, though it continued to raise new money as recently as 2016. Last year, the company canceled drug-development plans and began selling off its medicines.

What can Context do with Apristor that Arno didn't? "Arno pursued a different development path," for a different disease target, Context president Scott Applebaum emailed. He said it typically takes four years to get a successful Phase 2 drug to market, "but sometimes that time can be accelerated." A Stanford Law grad, Applebaum was a senior vice president at Shire Pharmaceuticals in Chesterbrook from 2004 to 2014, and served as top legal officer for Medgenics Inc. and Vitae Pharmaceuticals.

"There are no gurarantees in drug development," Applebaum added, "but we believe we are taking a rational approach to getting this drug approved. If approved, we believe it should be successful commercially."

Applebaum joined Context in November 2017. The company was cofounded in 2015 by Felix Kim, an assistant professor at Drexel University College of Medicine, and CEO Martin Lehr, who was an investor for Osage Partners, the Philadelphia venture capital firm from 2009 to 2015, and previously a researcher at Children's Hospital of Philadelphia and New York's Sloan-Kettering. He is a son of Seth Lehr, a partner with Ira Lubert and Howard Ross in $1.4 billion-asset, Philadelphia-based private-equity firm LLR.  Richard  Morris, Context's chief financial officer, who also joined the company in 2017, previously held the CFO job at Vitae.

Context employs seven people at its One Drexel Plaza headquarters, plus four consultants, and plans to nearly triple its staff by next year, Applebaum told me. The company is "actively recruiting multiple positions" to work on Apristor, he added.

Context's goal "is to build a fully integrated pharmaceutical company that is headquartered in Philadelphia, handling everything from drug discovery, to clinical development, to registration for approval, and ultimately commercialization," Applebaum said. That's in contrast to many small drug and biotech firms, which since 2000 have often been absorbed into large companies such as Johnson & Johnson.