Dive Brief:

• Sanofi will stop developing one of its top cancer drug prospects after the experimental treatment fell short in a late-stage study in advanced lung cancer, the company said Thursday.
• Trial monitors found the drug, dubbed tusamitamab ravtansine, missed both of its main study goals, failing to significantly delay tumor progression or extend patients’ lives compared to standard chemotherapy. Though a “trend” in survival was reported, Sanofi said it is ending development nonetheless.
• Sanofi has been testing the drug, a type of targeted cancer medicine known as an antibody-drug conjugate, in multiple lung cancer settings and against other tumor types. Despite the setback, it will continue “exploring the potential” of ADCs that involve a component of tusamitamab ravtansine and its target, a tumor protein called CEACAM5, according to the statement.

Dive Insight:

After years of ups and downs, ADC drug development has become one of the most competitive areas in oncology, spurred on by key technical advances, acquisitions and an uptick in approvals.

Like many of its pharmaceutical peers, Sanofi has built a presence through deals. Its interest dates back 20 years, when Aventis Pharmaceuticals, prior to its merger with Sanofi, formed an alliance with early ADC innovator ImmunoGen. That deal yielded the blood cancer drug Sarclisa and, in 2017, was amended to include an experimental ADC now known as tusamitamab ravtansine.

Since then, the drug has become a top prospect for Sanofi, which in recent years has struck several deals for cancer and immune disease medicines. Among the experimental cancer medicines in its pipeline, tusamitamab ravtansine is the only one in late-stage testing. Its target, CEACAM5, is overexpressed in a variety of epithelial tumors, including gastric, lung and colorectal cancers.

Early data in solid tumors showed enough promise for Sanofi to bet on a broad development program. But Sanofi is changing up its strategy after seeing the results of its first definitive test, a Phase 3 trial that compared it to the chemotherapy docetaxel in second-line lung cancer. Its decision to end development affects multiple mid-stage studies in other tumor types.

The company isn’t giving up on the approach, though. In its statement, Sanofi said it still intends to go after CEACAM5 with different ADCs that involve tusamitamab, the targeting component of the drug. Last year, for instance, it struck a deal with Seagen — now owned by Pfizer — to develop another ADC aimed at CEACAM5. Preclinical results were disclosed at a scientific meeting in March.

“Although the results are not what we hoped for, our research and work to advance potentially transformative therapies in areas of high unmet need for people living with cancer will not stop,” said Dietmar Berger, Sanofi’s chief medical officer, in a statement. “We will continue to explore the potential of CEACAM5 as a biomarker in cancer types where it is highly expressed.”