Two years ago, Dainippon Sumitomo inked a blockbuster $2.6 billion deal to buy Boston Biomedical, including a $200 million upfront payment. The prize catch in the deal was the promising BBI608, on the cutting edge of a new wave of therapies designed to target durable cancer stem cells. And as investigators pushed into Phase III for colorectal cancer, the Japanese parent installed Boston Biomedical in new digs in Cambridge, MA, last year.
But over the long holiday weekend Dainippon Sumitomo's shares took a beating--dropping 21% at one point, according to Bloomberg--as investors reacted to the news that BBI608 proved to be a dud in its most advanced trial for colorectal cancer. An independent monitoring board suggested that any further enrollment to the study should be stopped as the oral drug, used as a monotherapy, failed to clear an efficacy hurdle in the first interim analysis involving 97 patients.
The setback casts a pall over other biotechs operating in the same cancer stem cell field, including Verastem ($VSTM).
This isn't the end of the line for BBI608. Dainippon Sumitomo's Boston Biomedical team is pursuing other trials for combination therapies with paclitaxel and capecitabine for a variety of cancers, including ovarian and gastric cancers as well as colorectal cancer. Investigators will also continue to track overall survival rates in the unblinded Phase III study, though Japanese executives noted in a call with analysts that they do not expect to see anything positive come out of that.
The Boston Biomedical team is also doing trial work for the earlier-stage drug BBI503.
"DSP will continue all these ongoing clinical trials and proceed with the development of BBI608 with the aim to obtain its market authorization as early as possible," Dainippon said in a statement.
- here's the release (PDF)
- read the Bloomberg report