Results of Prostvac PROSPECT trial scheduled for later in 2017

According to Barvarian Nordic, the key results of the Phase III clinical trial of the immunologic agent Prostvac (rilimogene galvacirepvec/rilimogene glafolivec, or “rilimogene”) in treatment of metastatic, castration-resistant prostate cancer (mCRPC) are now expected in the second half of 2017.

The optimists among us had been hoping that we might hear the results of this trial at the annual meeting of the American Society for Clinical Oncology (ASCO) in June — or even earlier. However, it is clear from the Barvarian Nordic media release that some time between August and December 2017 is a much more likely timing. This large Phase III trial has enrolled nearly 1,300 patients at 200+ sites in 15 countries around the world.

The CEO of Barvarian Nordic is quoted as follows:

While we will have to await the final read out of the PROSPECT study to establish the efficacy of Prostvac, we are encouraged that the current monthly event rate has declined. This is great news for the patients. Not only is this consistent with an improvement in the standard of care for patients with mCRPC, which has been observed in recent years, but could also be indicative of a therapeutic effect of Prostvac as well.

As far as The “New” Prostate Cancer InfoLink is aware, Prostvac is the only new drug currently in development for treatment for advanced prostate cancer for which we can reasonably expect to hear the results of a major Phase III trial in 2017.

9 Responses

  1. Is this a good sign, bad sign, or can’t tell? Perhaps more of the patients involved are living longer and thus the trial can’t conclude yet or is it a paperwork exercise that is taking 6 months longer because it is a large trial?

  2. Jerry:

    As much as anything it’s probably because men with mCRPC are living slightly longer than they used to (because there are now multiple drugs they can take, each of which is probably having at least some beneficial effect). As a consequence, Barvarian Nordic may have underestimated just how long these patients would live when they were designing this trial (several years ago now, and before the approvals of either abiraterone acetate or enzalutamide).

    My thoroughly undocumentable gut feeling is that this trial is going to have a meaningful positive outcome … but anyone who’s looking for investment advice should not be considering my “gut feeling” as any sort of bankable insight. The truth is that I have no better information than anyone else about what this trial will show. Furthermore, I own no stock in this or any other drug company!

  3. These “gold standard” between group comparison research designs are so cumbersome that by the time the trial is completed the essential findings are already known or at least would be knowable had the study been conducted using N = 1 randomized research designs.

    Hard to escape the conclusion that we are guinea pigs for the drug companies looking to make big profits for their shareholders.

  4. Haha,

    I guess if it didn’t work for Dendreon it won’t work for other immunotherapies? I would hang in there for the results and then the treatment costs. Still a lot ahead to be determined. If, of course, the trials are successfully helping men.

  5. Dear pfadtag:

    I can assure you that the drug companies would be absolutely delighted not to have to do this type of large, randomized, controlled clinical trial to gain approval of their products. It would mean they could save a fortune in the development stages and still charge just as much as they thought the market would bear for their products.

    And I can also assure you that while N = 1 trials have a place in the development of new forms of therapy, they are only ever going to be a good idea in decisions to approve new forms of therapy for extremely rare disorders.

  6. It is almost mid-June 2017 now. I have mCRPC, and have been on Casodex, Zytiga, Xtandi, and am finishing up on radium-223. The last treatment left is another chemotherapeutic, which should take me safely to the end 2017. I am hoping that Prostvac becomes available before I die. I think I may need an additional few months. I may have to take my chances with some of these clinical trials, either before or after the chemo. I am shopping around now trying to find something. It’s not easy to get on these clinical trials.

  7. Bruce:

    IF data from the PROSPECT trial are positive when the announcement comes later this year (maybe in October or so), you may want to look for the developer to implement an “expanded access” trial soon afterwards but before FDA approval of the drug. Such studies are common today and are designed to allow people like you get access to new drugs like Prostvac as soons as possible after the results of trials are shown to be positive.

    The additional good news is that treatment with such drugs in expanded access trials comes at no cost to the patient.

  8. Hello Sitemaster:

    The data for Prosvtac was very positive in phase II. It extended life of for mCRPC patients by 8.5 months which is great, better than any other drug on the market.

    There are no developer to implement an “expanded access”. We are waiting for the outcome of the Phase III trial. In Phase III they have combined the prostate “vaccine” (ProstVac) with another drug (GM-CSF) that enhances the immune system. The hopes are that the combined drugs will extend the life of mCRPC patients by over a year (if the result is positive again). It is taking a long time for the Phase III participant to die.

  9. Dear Bruce:

    I have been carefully monitoring the ProstVac trials since about 2008 and am very familiar with the development of this agent. And while the data from the Phase II trial reported by Kantoff et al. in 2009 were certainly very promising (they actually showed an 8.2 month survival benefit compared to controls), we have to be very careful in consideration of those data.

    Barvarian Nordic has stated several time now that initial results are expected later this year, and no one is going to initiate an expanded access trial until they have the results from the Phase II trial. Also, since BMS has partered with Barvarian Nordic to market Prostvac in the USA, it may be BMS that would have control over any decisions about such an expanded access trial.

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