Blog Reader Comment

The patients enrolled in the different studies were very different with regard to stage and extent of disease - as a result the data can't be compared in this way, nor can they really be compared to Korn at all. Of the 3 studies, Biovex had the patients with the most advanced and extensive disease, Vical the next, and Provectus the patients with the least advanced and extensive disease. This is reflected in the graphs above, which would have been much the same with respect to PV-10 'looking better' irrespective of any treatment effect for any of the drugs.

A blog reader contributed the above comment in regards to my post PV-10 vs. OncoVEX, Allovectin-7. Thank you.

⊃ The patients enrolled in the different studies were very different with regard to stage and extent of disease...Of the 3 studies, Biovex had the patients with the most advanced and extensive disease, Vical the next, and Provectus the patients with the least advanced and extensive disease.

I agree (comparing all MM P2 trials, below):

Provectus management has maintained their focused label approach throughout the clinical trial, which is to apply PV-10 as a local-regional (loco-regional) treatment for early stage patients (Stage 3 and early-Stage 4 (i.e., 4a). As I recall, PV-10's MM P1 trial comprised 20 Stage 3 patients.

⊃ ...- as a result the data can't be compared in this way...

I agree. Even if one attempts to make an apples-to-apples comparison, which in the case of the reader's comment would be, at a minimum, to compare stage-by-stage rather than study-by-study numbers, if that, it would not be a true comparison and there is only so much information one can gain from it (i.e., the information should augment your thesis, long or short, not substantiate it. Comparisons, like analogies, should not be taken too far.

But, if we're comparing...

⊃ ...nor can they really be compared to Korn at all.

I disagree. Korn et al.'s graph was from the authors' meta-analysis of 42 phase 2 metastatic melanoma studies. The authors of this study did compare, by definition (i.e., confidence intervals). I think it is indeed valid for BioVex and Vical to compare themselves on this graph. Further, both BioVex and Vical chose to compare their results to Korn et al.'s study because they, BioVex and Vical, felt the comparison provided beneficial information (in reality, promotional in nature) to the medical and investor communities.

It is interesting to note Provectus management did not make such comparisons. Rather, they left it to the medical community to make their own comparisons and draw their own conclusions, however obvious such are or should be.

⊃ This is reflected in the graphs above, which would have been much the same with respect to PV-10 'looking better' irrespective of any treatment effect for any of the drugs.

Maybe, maybe not. The reader's comment appears to suggest that increasing stage and extent of the disease leads to lower efficacy, and that the stage and disease extent of patients in the respective trials dictated the companies' placement on the Korn et al. graph. Perhaps. Higher disease or tumor burden is an important concern for the patient and his or her physician.

But, what if inferior performance contributed to placement on the graph? If OncoVEX and Allovectin are not as good as PV-10, then they will reside lower on the graph. That is, OncoVEX and Allovectin produce lower overall survival than PV-10 because PV-10 is more efficacious.