Hi all --
It's been a while since I updated the
HPV (human papilloma virus) vaccine trial Barry's in -- he had his last phoresis a week ago (that's where they harvest white bood cells for the post-inoculation immune response tests) -- a two-hour procedure that the Hopkins people try to make as pleasant as possible but it is hard to make pushing all your blood through a machine and then putting it back in really nice! The movies on a large-screen TV and the body-sized heating pad help.
Barry's now had three of four injections with the DNA vaccine, abslutely no reaction which appears to be typical, although we noticed he has a slight touch of acne on his forehead and back. We met with Dr. Gillison (the principal investigator) last Friday and she noted this, but not sure if it's due to some immune response or just coincidental.
There wll be one more injection of the vaccine and a collection of cells (not a phoresis, though) in about two months. Then the next cohort will start, with the next-highest dose of the vaccine. Dr Gillison said there are only two spots open in the trial now -- if anyone is interested, it's for patients who have had an
HPV+ SCC of the oropharynx and who are at least 4 months post-treatment and considered cancer-free. Hopkins will test the tumor for
HPV if it has not been done already. There is at least one other member of this forum in the trial.
The analysis of all the results will wait until the whole trial is completed. A similar trial (same vaccine) with cervical cancer patients is being analysed, preliminary results indicate that the vaccine does boost the immune response to the virus and thus could help "clear" the virus from a patient.
This is the crux of the issue: What IS known is that patients who develop
HPV-induced cancers somehow have not "shed" the virus like the majority of us (80% of population is infected at some time in their lives but in only a few does the virus stick around and -- years later -- cause cancer). No one knows why this happens, the same individual may have a perfectly good immune response against influenza or other disease virus.
Barry asked Dr. Gillison this question and she said it was a good one, with no clear answer: If you have an
HPV+ cancer (cervical, oral) and you are successfully treated, is the virus still present? There is some evidence from cervical cancer that the virus may become inactive (latent) and then, come back. Dr. G. described an ongoing study in which a pathologist is looking -- slice by tiny slice -- at cervical tissue from women who were successfully treated for cancer in the past, no recurrence, but who now (for another reason) are having a hysterectomy. The tissue will be tested to see if the
HPV is still present in the cervix, although latent (inactive).
The goal of this DNA vaccine is to induce an immune response against the virus by boosting T-cell recognition -- the ultimate goal being to rid the patient of the virus and thus the chance of the cancer reappearing. In fact, in animal trials the vaccine alone was able to cause
HPV tumors to recede.
Once the Phase I of the trial is over, if the vaccine does cause an immune boost, then the next step might be to test against patients with active
HPV cancer (probably as an adjunct treatment).
Dr. Gillison confirmed her earlier statements about rate of recurrence of
HPV+ cancers (no more than 15%) and that most recur in first two years (which is the norm for HNC). The recurrence is usually in the lymph nodes and whether there was a ND or not doesn't seem to change that much. Barry is 18 months out now so keeping his fingers crossed!
The results of this Phase I trial will start to be analyzed after the end of the fourth (highest dose) cohort so still some time off.
Gail
