•John Hopkins Researchers Develop Anti-Cancer Compound
A vaccine that could facilitate protection against chlamydia is closer to becoming reality after a pioneering clinical trial found the treatment to be safe.
The vaccine according to The Guardian report, successfully provoked an immune response, boosting levels of antibodies against the chlamydia bacterium in the blood and vaginal fluids.
About 131m cases of the sexually transmitted infection are diagnosed worldwide every year. The study is seen to represent a significant step towards a preventive treatment for world’s most common sexually transmitted disease. Chlamydia can be treated with antibiotics, but infection often has no symptoms and many people are unaware they have it. Without treatment, it can lead to a range of complications for men and women, including fertility issues and an increased risk of HIV.
Dr. Frank Follmann, the head of chlamydia vaccine research at Staten’s Serum Institute in Denmark and a co-author of the study, said: “Chlamydia is a hidden epidemic. It is very well adapted to infecting both men and women and in most cases it does it without any symptoms.”
There have been recent drives to improve testing through screening programmes, particularly among young people, but the study’s authors say such measures have failed to tackle the problem and suggest a vaccine would be beneficial.
Writing in the Lancet Infectious Diseases journal, the researchers describe how they tested two formulations of a vaccine, with each type given to 15 women aged between 19 and 45 who did not have chlamydia. Another five chlamydia-free women were given a placebo. All received three injections into their arm muscle over four months, followed by two doses administered through a nasal spray in the weeks after. Neither the women nor those monitoring the impact of the vaccine were aware of who was in which group. The results showed no serious adverse reactions to the vaccines. The vaccinations, but not the placebo, produced an immune response.
Follmann said the presence of antibodies in vaginal fluid was important. “We see the antibodies as a first line of defence,” he said. “They should be able to target the bacteria once it enters the genital tract.” He said the study suggested the injection could provide sufficient protection against chlamydia, without the need for the nasal spray. The findings raise hopes that the vaccine could eventually be given at the same time as the Human Papilloma Virus (HVP), which protects against certain cancers including that of the cervix. The treatment is still at an early stage of development, but the team said the trial results were promising and that testing should proceed to the next stage with a larger number of participants.
“The next step is to test whether or not it could in fact protect [against chlamydia infection] in humans,” Follmann said.
In a related development, researchers at Johns Hopkins Medicine in the United States have developed a compound to block glutamine metabolism, slowing tumour growth, altering the tumour microenvironment and boosting the anti-tumour T-cell generation.
The compound, JHU083, is a prodrug version of glutamine antagonist, DON, designed to become active and functional within the tumour.
As glutamine is necessary for tumour metabolism, JHU083 is expected to help treat various cancers. Researchers added that the drug selectively targets tumour cells. Johns Hopkins Kimmel Cancer Centre Bloomberg-Kimmel Institute for Cancer Immunotherapy associated director, Jonathan Powell said: “By targeting glutamine metabolism, we were not only able to inhibit tumour growth and change the tumour microenvironment but also alter the T-cells in a way that we markedly enhanced immunotherapy for cancer.”
Pharmaceutical Technology reports that when tested in mice models of colon cancer, lymphoma and melanoma, the drug candidate was able to significantly reduce tumour growth and improve survival by targeting tumour cell metabolism and tumour microenvironment. Permanent cures were observed with JHU083 in mice via triggering of the anti-tumour immune response. Furthermore, the cancer-free mice rejected the reinjection of new tumours, suggesting an immune memory that could identify and attack cancer. Further research showed improved anti-tumour effects with simultaneous administration of JHU083 plus an anti-PD-1 checkpoint inhibitor, compared to anti-PD-1 therapy alone.
Powell added: “Initially, we thought we would need to use the two therapies sequentially in order to avoid any potential impact of the metabolic therapy on the immunotherapy. “Remarkably, however, it turned out that the combined treatment worked best when we gave them simultaneously.” Researchers also found that the compound could boost the efficacy of adoptive cellular therapy indicating its use to enhance CAR-T cell therapy.
The team is also planning to study JHU083 in combination with various types of immunotherapy.
By Chigbu Nwaobia