March 2017 - Latest news with potential next approved ADC Sacituzumab Govitecan - Triple negative br
Hello! This months posting I hope you will find interesting because its about Sacituzumab Govitecan (SG) and its impressive clinical study results and what that could mean for this ADC soon entering the market and benefitting women with triple negative breast cancer (TNBC).
SG is a an interesting ADC in itself because its construction is an improvement over the current ADCs Kadcyla or Adcetris, First of all, SG targets a Trop-1 that is a new and exciting target discovered for TNBC. SG is attached to the Topoisomerase I inhibitor SN-38. What is unique is that the antibody is loaded with 8 drugs rather than the typical 2. The industry has a big problem with trying to load ADCs with high numbers of drugs, mostly because the drugs cause a hydrophobic effect that kills tumor targeting when injected inside patients. Immunomedics, the maker of SG, chose to counteract this hydrophobicity by using hydrophilic PEG molecules in the crosslinker design. The result was an ADC with more drugs but with good pharmacokinetics and tumor uptake.
Fast forward about 5 years, and this latest study in patients (69) with TNBC that had received a median of 5 previous treatments including check point inhibitor therapy (i.e. immunotherapy) had an objective response rate of 30%. Importantly, the median overall survival was 11.1 months. This provides meaningful proof that SG works and should get fast track approval by the FDA.
On a side note, a judge just recently blocked a $2Billion deal between ADC giant Seatlle Genetics and Immunomedics. There is a current struggle for the board at immunomedics where VenBio (a venture capital group in San Francisco) believes the deal should be worth more. We’ll wait and see what happens, but hopefully this drug does get access to market soon and many women could benefit. TNBC disproportionally affects young women and is very aggressive.