The vaccine could help avoid damaging cervical treatments. (Sharon Gekoski / Philadelphia Inquirer)
Vaccine clears cervix of dangerous HPV lesions in half of women, study shows.
Scientists have used a genetically engineered vaccine to successfully eradicate high-grade precancerous cervical lesions in nearly half of women who received the vaccine in a clinical trial. The goal, say the scientists, was to find nonsurgical ways to treat precancerous lesions caused by HPV.
“Every standard therapeutic option for women with these lesions destroys part of the cervix, which is particularly relevant for women of childbearing age, who may then be at risk for pre-term birth due to a weakened cervix,” said Dr. Cornelia Trimble, professor of gynecology and obstetrics, oncology, and pathology at the Johns Hopkins University School of Medicine, and first author of the new report, which appeared online Sept. 17 in The Lancet. “A vaccine able to cure precancerous lesions could eventually be one way women can avoid surgery that is invasive and can also harm their fertility.”
High-grade cervical lesions, termed CIN2/3, occur most often in women 40 or younger, according to Trimble, a member of Johns Hopkins’ Kelly Gynecologic Oncology Service and Kimmel Cancer Center. Because the lesions can progress to cancer, they are usually removed by surgery, freezing or laser. The procedures are successful in removing the precancerous areas in approximately 80 percent of women, Trimble said. Less troublesome lesions, called low-grade dysplasia, usually are monitored by physicians rather than immediately removed because they pose less of a risk for cancer and usually regress on their own.
For the study, the scientists used a vaccine, originally developed by University of Pennsylvania scientist David Weiner. It is engineered to teach immune system cells to recognize precancerous and cancerous cells. Those cells are coated with proteins linked to an infection with two strains of HPV — 16 and 18 — that cause cervical cancer. The vaccine, given by injection into the arm, is made by Inovio Pharmaceuticals Inc., which funded the clinical trial, and whose employees co-authored the report with Trimble.
In 2011 through 2013, the scientists recruited 167 women, ages 18 to 55, with newly diagnosed, high-grade precancerous cervical lesions. The women were randomly assigned to receive either three doses of the vaccine or saline injections over a 12-week period at 36 hospitals and private gynecology practices in the U.S. and six other countries.
After each of the injections, the scientists gave the women a small electric pulse at the site of the injection. Cells near the electric pulse open their pores, Trimble said, increasing the likelihood that the vaccine will be taken up by immune system cells.
Of 114 women who received at least one vaccine dose, 55 (48.2 percent) had a regression of their precancerous lesion, meaning their lesions disappeared or converted to low-grade lesions, compared with 12 of 40 (30 percent) who received saline injections. Of the 114 in the vaccine group, 107 received all three vaccine doses, and 53 of them (49.5 percent) had regression of their lesions. Of the 40 in the saline group, 36 got all three injections, and 11 of them (30.6 percent) had regression of their lesions. Thirteen women dropped out of the study after enrollment.
Two patients discontinued the study because of pain at the injection site. Skin redness was more common in the vaccine group compared with saline.
Among women who completed all three injections, scientists could find no trace of HPV in the cervices of 56 of the 107 women who received the vaccine, compared with only nine of 35 saline recipients.
“In many of these women, the vaccine not only made their lesions disappear, but it also cleared the virus from their cervix,” Trimble said. “In most unvaccinated patients whose lesions went away, the virus was still present, and many still had low-grade lesions.”
Trimble said clearance of the virus is a “significant bonus” from receiving the vaccine because persistent HPV infection is a major risk factor for recurrence of cervical lesions.
After 12 weeks, doctors surgically removed lesions that did not regress and took biopsies of each study participant’s cervix. In the surgically removed lesions, scientists found minuscule cancers in two of the women who received the vaccine. Trimble says these microinvasive cancers are rarely diagnosed by a biopsy but are found in surgical specimens.
In the biopsy samples, the scientists found that patients whose lesions completely regressed after treatment had more immune cells, called T cells, present in the tissue. “It’s important that T cells capable of recognizing HPV stay in the cervix and fight off any recurrence of the infection,” says Trimble.
“This is a great first step,” says Trimble. “We showed that the vaccine may enable an immune response in a person whose immune system was initially not adequately engaged or was hampered in some way so as to let the lesion occur.”
Trimble said that precancerous lesions are unlikely to progress to cancer during the vaccine treatment period, and monitoring of high-grade lesions is done routinely for pregnant women. “It typically takes about 10 or more years for precancerous cells to become cancer, so there is a window of opportunity to intervene with nonsurgical approaches to reverse the process of viral-associated cancers,” Trimble said.
Trimble received an unrestricted grant from Inovio Pharmaceuticals Inc., but she has no other financial or consulting arrangements with the company.
In addition to Trimble, scientists who contributed to the research include Lance Edwards from Suffolk Obstetrics and Gynecology in Port Jefferson, New York; R. Lamar Parker from Lyndhurst Gynecologic Associates in Winston-Salem, North Carolina; Lynette Denny from the University of Cape Town’s Groote Schuur Hospital in South Africa; David B. Weiner from the University of Pennsylvania; and Matthew P. Morrow, Kimberly A. Kraynyak, Xuefei Shen, Michael Dallas, Jian Yan, Mary Giffear, Ami Shah Brown, Kathleen Marcozzi-Pierce, Divya Shah, Anna M. Slager, Albert J. Sylvester, Amir Khan, Kate E. Broderick, Robert J. Juba, Timothy A. Herring, Jean Boyer, Jessica Lee, Niranjan Y. Sardesai, David B. Weiner and Mark L Bagarazzi from Inovio Pharmaceuticals Inc.
Correction: Since posting this review, we’ve learned that this story wasn’t an original piece of journalism but rather a verbatim reprint of a news release from the Johns Hopkins Kimmel Cancer Center. There was no warning or disclaimer as to the origin of the text. Accordingly, we’ve downgraded the score from 4 stars to 0, to reflect the fact that this wasn’t a piece of original journalism. Read this related blog post for further explanation.
This very thorough analysis of a newly published study of an experimental vaccine had much to admire, including clear quantification of benefits and an acknowledgment of study dropouts and potential harms. It could have been improved by two things: an independent source or two providing their take on the publication and some information about what the vaccine might ultimately cost patients and insurers.
The development of a vaccine to prevent human papilloma virus (HPV) infection was a big advance in efforts to prevent cervical cancer. This study shows that a similar experimental vaccine can be of benefit to women who’ve already been infected with HPV and whose cervixes show evidence of precancerous changes. According to the study, the new vaccine can boost the body’s natural immune response and cause high-grade precancerous changes in the cervix to regress. It can also help clear the virus from the cervix, reducing the risk of future cancers. The current treatments for precancerous changes all involve some form of invasive procedure with tissue destruction in the cervix, which can compromise future childbearing ability. Thus the vaccine may offer a significant advantage over currently available treatments.
The story did not discuss the potential costs of the experimental vaccine. Since similar vaccines are commercially available, it should have been possible to provide at least a ballpark estimate of what the new vaccine might cost. The potential savings in terms of treatment costs for prevented cancers could also have been mentioned and discussed.
The story makes a clear comparison of the benefits of the vaccine, both in raw numbers and in percentages. It says, “Of 114 women who received at least one vaccine dose, 55 (48.2 percent) had a regression of their precancerous lesion, meaning their lesions disappeared or converted to low-grade lesions, compared with 12 of 40 (30 percent) who received saline injections.” It also says that, “Among women who completed all three injections, scientists could find no trace of HPV in the cervices of 56 of the 107 women who received the vaccine, compared with only nine of 35 saline recipients.”
The story does take the rare step of calling out the fact that some patients dropped out of the study and of spelling out the side effects, even though they were minimal. It says, “Two patients discontinued the study because of pain at the injection site. Skin redness was more common in the vaccine group compared with saline.”
The story does a nice job of explaining the quality of the evidence, including the sample size, the way the study was conducted, and the different phases of the study. It also notes where the study was published. Some comment on the limitations of the trial, which were discussed in some detail in the study itself, would have been welcome and likely would have been provided by an independent expert. But since none of these limitations seem to seriously compromise the interpretation of the study, we’ll let this omission pass.
There is no disease mongering in the story.
We wished that the story had interviewed an independent source. It did, however, note that the study was funded by the company that makes the vaccine. It said, “The vaccine, given by injection into the arm, is made by Inovio Pharmaceuticals Inc., which funded the clinical trial, and whose employees co-authored the report with Trimble.” Although we can’t award a Satisfactory here, the story earns our appreciation for this clear statement on potential conflict of interest.
The story discussed the fact that typically precancerous lesions are either removed through surgery or watched to see how they progress. The vaccine would be a less invasive option than the surgery.
The story called the study a “first step,” and we think it’s reasonably clear that this was an early human clinical trial and that the vaccine is still not available for widespread use.
The story explains what may be novel about the study and the vaccine: “A vaccine able to cure precancerous lesions could eventually be one way women can avoid surgery that is invasive and can also harm their fertility.” But it doesn’t acknowledge that this type of immunotherapy approach is being investigated by a number of other research teams who’ve already published findings.The study itself tell us that “Previous attempts to develop a non-surgical treatment for CIN2/3 have had mixed success,” and it goes on to describe the results of a number of open label studies and randomized controlled trials of other similar therapies — some of which are reported to be at least moderately successful. Even a line about that context, and what makes the current approach different or better, would have been helpful.
The story did not rely on a news release.