Sesen (SESN) stock tumbled nearly 40% following lousy preliminary results for the company’s Phase 3 study of Vicinium for the treatment of Non-Muscle Invasive Bladder Cancer (NMIBC). Despite upping the frequency in dosing, not much changed between the Phase 2 and Phase 3 studies. Out of 93 patients involved, 88 reached the 12-month mark and achieved a complete response rate (CRR) of 14%, which is actually 2% less than the 16% rate achieved in the previous Phase 2 study. The results were also lacking for the 3, 6 and 9-month CRR when compared to the Phase 2 study. Needless to say, investors are discouraged.
H.C Wainwright’s analyst Swayampakula Ramakanth says the news introduces uncertainty on the regulatory and commercial prospects of Vicinium. As a response, he knocks down his rating from Buy to Neutral, while cutting the price target to $1.00 (from $3.00). (To watch Ramakanth’s track record, click here)
However, the analyst doesn’t completely count this drug out of the running: “While the VISTA results did Vicinium no favors with regards to securing regulatory approval in the US, the drug still has a decent chance of getting through the FDA due to the high unmet medical need for post-BCG NMIBC. There are approximately 62,000 new NMIBC patients diagnosed in the US every year, and while NMIBC is one of the most treatable cancers with a 5-year survival rate of approximately 88%, it is also a cancer with a high recurrence rate and a high disease burden. As a result, in terms of total cost per patient, bladder cancer is the most expensive of all cancers to treat. Furthermore, while BCG immunotherapy is initially effective in most NMIBC patients, up to 20% of patients discontinue treatment due to intolerance, and another 50% fail BCG within 6 months. Unfortunately for patients who progress or are intolerant of BCG, currently the only approved and effective post-BCG therapy is complete bladder removal (cystectomy), which can lead to incontinence, erectile dysfunction, and a reduced quality of life. Therefore, despite the unimpressive 12-month CRR, we believe that Vicinium still has a 60% chance of being approved in the US for the treatment of BCG-unresponsive NMIBC.”