There is reason to think that a drug like this would be broadly effective against different kinds of cancer. TR100 disrupts the actin cytoskeleton vital to all cells, and specifically disrupts its formation by targeting an isoform of the protein tropomyosin. Isoforms are different structures for the the same protein- every cell needs tropomyosin to regulate their actin filaments, but cancer cells preferentially use a certain structure of tropomyosin. Compounds with anti-actin activity have been looked at for a long time as anticancer compounds, but the known ones have been nonspecific. TR100 also has the advantage of being a relatively simple small molecule instead of a complicated biomolecule, which could make its development as a commercial drug much easier.
It is however, still (potentially) just a new chemotherapy agent, one of many out there. From what has been observed from other chemo agents, just because a compound targets a basic cellular function doesn't mean a cancer can't develop resistance. The taxanes and the Vinca alkaloids arrest mitosis (by targeting microtubules), and are excellent, widely used drugs, but are not the The Cure for Cancer. I'd imagine this compound to be along those lines- another weapon in the oncology arsenal, but not a magic bullet.