Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.
What: Shares of Puma Biotechnology (PBYI 0.40%), a clinical-stage biopharmaceutical company developing therapies to treat various forms of cancer, jumped higher by as much as 58% after reporting positive top-line results from its phase 2 I-SPY 2 trial with PB272 (known scientifically as neratinib) as a neoadjuvant treatment for stage 2 or higher breast cancer.
So what: According to Puma's press release from yesterday, in its randomized 300-patient confirmatory trial, neratinib -- when combined with paclitaxel and followed by doxorubicin and cyclophosphamide -- should demonstrate a high rate of success in late-stage trials with the HER2-positive/HR-negative signature. Within this grouping, the neratinib arm delivered a p-value of 0.053, or a 94.7% probability of superiority over the current standard of treatment according to Bayesian predictive models. Furthermore, neratinib-based regimens demonstrated a Bayesian probability of superiority over paclitaxel plus Herceptin of 78.1% if they were to go head to head in a phase 3 trial.
Now what: Simply put, no one really expected Puma's results to be this strong, which is why we're seeing such a monstrous move to the upside. Not to sound like a broken record, but I would still like to see the full data before stating my full opinion on Puma (the company will release its full data at a scientific meeting in the future). I've witnessed far too many cancer drugs demonstrate promise in mid-stage trials only to disappoint in late-stage trials, so my thought at the moment is that sticking to the sidelines until we're well into late-stage trials might be the smartest course of action.
