There’s been a vast amount of work (and excitement) in the immunotherapy approaches to cancer in the last few years. Here’s a report on one that I’d missed: IMM-101, which is not directed to PD-1 or PD-1L1, not an engineered T-cell, or any of the other things that have been in the news. It’s a killed preparation of the bacterium Mycobacterium obuense, which mixture seems to have broad immunomodulatory activity.
This paper details the clinical results of this agent added to standard-of-care for pancreatic ductal adenocarcinoma. That, as many will recognize is one of those cancers with hideous one-year survival rates – very bad news indeed. And there’s not a lot that slows it down. But this trial in 75 patients (35 controls got gemcitabine alone) showed an interesting result. You might not think so, to look at the bottom line, which was an overall non-significant survival benefit. But the predefined metastatic group actually did show what could be a significant effect, and that’s unfortunately cancelled out by the localized tumor patients, who actually died more quickly in the treatment group. There have been some headlines about this study, but (perhaps understandably) none of them mention that last part.
A similar effect (greater efficacy against metastases) had been seen in preclinical studies on mice and in cell culture, which is surely why this Phase II trial had the predefined patient groups. But I don’t think anyone expected the reverse effect in the nonmetastatic patients, if indeed that’s real. Informed by this, further trials will look at metastatic patients alone. It’s worth noting that the gemcitabine control group had survival numbers that were a little on the low side, compared to what was expected, and that gemcitabine alone is not (by now) necessarily what you’d compare against (the patients in this study started enrolling in 2011). But this does look worth a follow-up, especially since IMM-101 seems to have added no particular toxicity or adverse events in the treatment group. Hold the headlines for a bit, though. . .