Most cancers arise in adults, which is why most funds are targeted toward research into those cancers. But osteosarcoma, a bone cancer, tends to affect adolescents.
Current treatments are only effective for around 60 per cent of osteosarcoma patients – a survival rate that hasn’t changed in four decades. For the four out of ten children who are not cured, lives are cut short very early.
Therapies are intensive and can cause heart and kidney damage, secondary cancers and more. This means quality of life for those who survive can be dramatically and adversely affected.
Associate Professor Christine Hawkins from La Trobe University is leading a team of researchers whose goal is to improve the efficacy and safety of osteosarcoma therapies. Hawkins and her colleagues are looking for treatments that work through different molecular pathways to kill cancer cells without causing other, healthy cells to mutate.
“This is a big issue for patients being treated for cancer when they’re young, because if they’re cured they have plenty of decades of life for the organ damage and mutation caused by the therapy to lead to new cancers and other health problems,” Hawkins says. “We’re trying to avoid short-term side effects as well as those other, potentially lethal, long-term side effects.”
“In an earlier study we tested many different drugs that work in different ways. We found a class of drugs known as Smac mimetics, that seemed promising in terms of their ability to kill the osteosarcoma cells in the lab. After that screening process, we began looking at these drugs more closely.”
In mice modelling, the drug was not only effective in treating the original tumours, but also cleared metastatic tumours that spread around the body and into the lungs.
“That is why we’ve been particularly excited about the work we’ve been doing over the last year or so,” Hawkins says. “It wasn’t successful in every case, but these models are very aggressive, so we were thrilled to see that in some cases we couldn’t see any further trace of tumours.”
“We think this is very promising and we now need to get going and take several further steps before we can consider testing and using these drugs in humans.”
Interestingly, this drug class is currently in clinical trials in adults. These trials are focussing on carcinomas such as breast cancers and also some types of blood cancers.
Read more: Exploring better and safer treatments for osteosarcoma
“There are a number of drugs in this class and the one we’ve been focussing on is known as LCL-161,” Hawkins says. “We’re focussing on this one because it’s one of the most effective drugs we tested, and also because it has progressed relatively far through human clinical trials. This could save us several years of research.”
“We hope that once we do a few more of these experiments and are ready to move into clinical trials in osteosarcoma patients, we can capitalise on all of the knowledge that's been developed through those other clinical trials, including how you deliver the drug and how much is safe, etc. ”
The team is not yet ready to begin its own clinical trials. The next step is to conduct further testing in the lab to ensure the immune system will work the way it would be expected with the drug – that is, in partnership to kill off cancer cells.
“The results so far are very encouraging, but we need to check that it works with the immune system before we can set up clinical trials,” Hawkins says.
The next stage of research will likely take around two years. If that is successful, clinical trials will run for several years. Assuming all goes well, a new treatment could be available within a decade, she says.
“Funding is vital because we need to pay for all of the people and reagents to do the research,” Hawkins says. “We have to pay for equipment and we have to pay journals to publish the findings. The work itself is quite expensive and without funding it simply won’t happen.”
“Receiving funding from an organisation like The Kids’ Cancer Project gives us very strong motivation to work hard and get stuff done. The knowledge that people have donated that money, that they are supporting you and they have your back – there is a psychological element that can be very motivational.”