The anti-cancer drug abemaciclib (also known as Vernezio) has this month been added to the Australian Pharmaceutical Benefits Scheme (PBS) to treat certain types of breast cancer.

This significantly reduces the cost of the drug. A patient can now expect to pay A$31.60 for a 28-day supply ($7.70 with a health care concession card). The price of abemaciclib without government subsidy is $4,250.

So what is abemaciclib, and how did we get to this point?

It stops cells dividing

Researchers at the pharmaceutical company Eli Lilly developed abemaciclib and published the first study on the drug (then known as LY2835219) in 2014.

Abemaciclib is a type of drug known as a “cyclin-dependent kinase inhibitor”. It’s taken as a pill twice a day.

To maintain our health, many of the cells in our bodies need to grow and divide to produce new cells. Cancers develop when cells grow and divide out of control. Therefore, stopping cells from dividing into new cells is one way that cancer can be fought.

When cells divide, they have to make a copy of their DNA to pass onto the new cell. “Cyclin-dependent kinases” (CDKs for short) are essential for this process. So, if you stop the CDKs, you stop the DNA copying, you stop cells dividing, and you fight the cancer.

However, there are different types of CDKs, and not all cancers need them all to grow. Abemaciclib specifically targets CDK4 and CDK6. Thankfully, a lot of cancers do need these CDKs, including some breast cancers.

But abemaciclib will only be effective against cancers that rely on CDK4 and CDK6 for continued growth. This specificity also means abemaciclib is fairly unique, so it can’t easily be replaced with a different drug.

Two other CDK4/6 inhibitors were developed around the same time as abemaciclib, and are called ribociclib and palbociclib. Both of these drugs are also on the PBS for specific types of breast cancer. As the drugs differ in their chemical structures, they have slight differences in the way they are taken up and processed by the body. The preferred drug given to a breast cancer patient will depend on their unique circumstances.

What are the side effects?

Research is still ongoing into the differences between each of these CDK4/6 inhibitors, but it is known that the side effects are largely similar, but can differ in severity.

The most common side effects of abemaciclib are fatigue, diarrhoea and neutropenia (reduced white blood cells). The gastrointestinal issues are generally more severe with abemaciclib.

If these side effects are too severe, abemaciclib treatment can be stopped.

What types of cancer has abemaciclib been approved for?

In 2017, the United States Food and Drug Administration (FDA) approved abemaciclib for the treatment of patients with metastatic HR+/HER2- (hormone receptor-positive and human epidermal growth factor receptor 2-negative) breast cancer who did not respond to standard endocrine therapy.

Australia’s Therapeutic Goods Administration (TGA) similarly approved abemaciclib in 2022 as an “adjuvant” therapy (after the initial surgery to remove the tumour) for patients with HR+/HER2- invasive early breast cancer which had spread to lymph nodes and was at high risk of returning.

As of May 1 2024, the PBS covers this use of abemaciclib in combination with endocrine therapy such as fulvestrant, which is also listed on the PBS. Endocrine therapy, also known as hormonal therapy, blocks hormone receptor positive (HR+) cancers from receiving the hormones they need to survive.

Could abemaciclib be used for other cancers in the future?

Abemaciclib is of great interest to scientists and medical practitioners, and testing is ongoing to assess the effectiveness of abemaciclib in treating a range of other cancers, including gastrointestinal cancers and blood cancers.

Abemaciclib may even be usable in brain cancers, as it has long been known to be capable of crossing the blood-brain barrier, a common stumbling block for potential anti-cancer drugs.

Time will tell whether the role of abemaciclib in health care will be expanded. But for now, its inclusion on the PBS is sure to bring some relief to breast cancer patients nationwide.

Sarah Diepstraten, Senior Research Officer, Blood Cells and Blood Cancer Division, Walter and Eliza Hall Institute and John (Eddie) La Marca, Senior Resarch Officer, Walter and Eliza Hall Institute

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A vaginal birth after caesarean (known as a VBAC) is when a woman who has had a caesarean has a vaginal birth down the track.

In Australia, about 12% of women have a vaginal birth for a subsequent baby after a caesarean. A VBAC is much more common in some other countries, including in several Scandinavian ones, where 45-55% of women have one.

So what’s involved? What are the risks? And who’s most likely to give birth vaginally the next time round?

What happens? What are the risks?

When a woman chooses a VBAC she is cared for much like she would during a planned vaginal birth.

However, an induction of labour is avoided as much as possible, due to the slightly increased risk of the caesarean scar opening up (known as uterine rupture). This is because the medication used in inductions can stimulate strong contractions that put a greater strain on the scar.

In fact, one of the main reasons women may be recommended to have a repeat caesarean over a vaginal birth is due to an increased chance of her caesarean scar rupturing.

This is when layers of the uterus (womb) separate and an emergency caesarean is needed to deliver the baby and repair the uterus.

Uterine rupture is rare. It occurs in about 0.2-0.7% of women with a history of a previous caesarean. A uterine rupture can also happen without a previous caesarean, but this is even rarer.

However, uterine rupture is a medical emergency. A large European study found 13% of babies died after a uterine rupture and 10% of women needed to have their uterus removed.

The risk of uterine rupture increases if women have what’s known as complicated or classical caesarean scars, and for women who have had more than two previous caesareans.

Most care providers recommend you avoid getting pregnant again for around 12 months after a caesarean, to allow full healing of the scar and to reduce the risk of the scar rupturing.

National guidelines recommend women attempt a VBAC in hospital in case emergency care is needed after uterine rupture.

During a VBAC, recommendations are for closer monitoring of the baby’s heart rate and vigilance for abnormal pain that could indicate a rupture is happening.

If labour is not progressing, a caesarean would then usually be advised.

Why avoid multiple caesareans?

There are also risks with repeat caesareans. These include slower recovery, increased risks of the placenta growing abnormally in subsequent pregnancies (placenta accreta), or low in front of the cervix (placenta praevia), and being readmitted to hospital for infection.

Women reported birth trauma and post-traumatic stress more commonly after a caesarean than a vaginal birth, especially if the caesarean was not planned.

Women who had a traumatic caesarean or disrespectful care in their previous birth may choose a VBAC to prevent re-traumatisation and to try to regain control over their birth.

We looked at what happened to women

The most common reason for a caesarean section in Australia is a repeat caesarean. Our new research looked at what this means for VBAC.

We analysed data about 172,000 low-risk women who gave birth for the first time in New South Wales between 2001 and 2016.

We found women who had an initial spontaneous vaginal birth had a 91.3% chance of having subsequent vaginal births. However, if they had a caesarean, their probability of having a VBAC was 4.6% after an elective caesarean and 9% after an emergency one.

We also confirmed what national data and previous studies have shown – there are lower VBAC rates (meaning higher rates of repeat caesareans) in private hospitals compared to public hospitals.

We found the probability of subsequent elective caesarean births was higher in private hospitals (84.9%) compared to public hospitals (76.9%).

Our study did not specifically address why this might be the case. However, we know that in private hospitals women access private obstetric care and experience higher caesarean rates overall.

What increases the chance of success?

When women plan a VBAC there is a 60-80% chance of having a vaginal birth in the next birth.

The success rates are higher for women who are younger, have a lower body mass index, have had a previous vaginal birth, give birth in a home-like environment or with midwife-led care.

For instance, an Australian study found women who accessed continuity of care with a midwife were more likely to have a successful VBAC compared to having no continuity of care and seeing different care providers each time.

An Australian national survey we conducted found having continuity of care with a midwife when planning a VBAC can increase women’s sense of control and confidence, increase their chance to be upright and active in labour and result in a better relationship with their health-care provider.

Why is this important?

With the rise of caesareans globally, including in Australia, it is more important than ever to value vaginal birth and support women to have a VBAC if this is what they choose.

Our research is also a reminder that how a woman gives birth the first time greatly influences how she gives birth after that. For too many women, this can lead to multiple caesareans, not all of them needed.

Hannah Dahlen, Professor of Midwifery, Associate Dean Research and HDR, Midwifery Discipline Leader, Western Sydney University; Hazel Keedle, Senior Lecturer of Midwifery, Western Sydney University, and Lilian Peters, Adjunct Research Fellow, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.