Hope for ‘silent killer’ cancers? New drug that targets blood vessels around tumors – not the cancer itself – stalled the disease in mice
- Silent killer cancers seem to trick the body into producing more of a protein called MFAP5
- MFAP5 is the fuel needed to generate new blood vessels and excess tissue
- Each new web of blood vessels and tissue that form are a whole new ‘micro-environment’ for the tumors to feed off, grow, and strengthen
- Blocking MFAP5 stalled the cancer in mice and made their chemo more effective
Scientists have created a promising new way to treat late-stage ovarian and pancreatic cancers.
The cancers are two of the most lethal and are known as ‘silent killers’ because they rarely trigger early symptoms and often go undetected until it is too late.
Tests on mice showed a new kind of immunotherapy that targets the cells that grow around and support tumors.
The drug will undergo further tests this year and, if successful, human trials will begin in 2020.
Silent killer cancers seem to trick the body into producing more of a protein called MFAP5, because it is the fuel needed to generate new blood vessels and excess tissue. Each new web of blood vessels and tissue that form are a whole new ‘micro-environment’ for the tumors to feed off, grow, and strengthen. Blocking MFAP5 stalled the cancer in mice
It’s rare for ovarian or pancreatic cancers to be spotted early.
By the time sufferers show symptoms – such as bloating for ovarian or jaundice for pancreatic – they have likely reached the late stages, when it has spread further, making it much harder to treat.
As such, ovarian cancer is the sixth most common cause of cancer death, accounting for five percent of female cancer deaths a year. Treatment has improved for pancreatic cancer in the last decade, but it remains one of the most deadly.
Immunotherapy – training a patient’s immune system to seek, attack and kill cancer itself – has been a gamechanger for all cancers.
But this new research by researchers at Houston Methodist Cancer Center shows a specific approach to immunotherapy can be particularly useful for the hardest-to-treat cancers, attacking the disease and making other treatments more effective.
The key was not to target the tumor itself, but to focus on MFAP5, a protein secreted by cells, which seems to be particularly elevated in people with ‘silent killer’ cancers.
For some reason, which is not yet entirely clear, the higher a patient’s MFAP5 levels, the poorer their prognosis.
The team – a collaboration between Houston Methodist Cancer Center and The University of Texas MD Anderson Cancer Center – suspected the MFAP5 might be providing sustenance to the tumors.
According to their latest research, published today in the journal Clinical Cancer Research, they might be right.
By blocking MFAP5, the researchers were able to prevent the tumor from feeding on other cells.
In mice, this approach stopped the cancer from growing, and suddenly they saw the chemotherapy working more effectively.
According to Dr Samuel Mok, a co-author on the paper at MD Anderson, these cancers seem to trick the body into producing more MFAP5, because it is the fuel needed to generate new blood vessels and excess tissue (a process called ‘fibrosis’).
Each new web of blood vessels and tissue that form are a whole new ‘micro-environment’ for the tumors to feed off, grow, and strengthen.
‘MFAP5 promotes fibrosis in ovarian and pancreatic cancers, and fibrosis promotes progression, chemoresistance and reduces survival of people with these cancers,’ Dr Mok said.
‘By blocking this secretory protein with an antibody, we can treat the tumor by targeting multiple cellular types – fibroblasts and blood vessels – in the tumor micro-environment.’
A humanized version of the drug is due to go efficacy and toxicity testing later this year before clinical trials in 2020.
The team has filed a joint patent.