Riding with resilience — one woman’s journey with metastatic breast cancer

Texas native Paula Bartuska loves riding her motorcycle. She enjoys unwinding in nature and spending time with family at their cabin. But her life hasn't been easy, and she doesn't take these moments of joy for granted. When she was 31, Bartuska felt a lump in her breast. Despite her young age, a biopsy revealed she had early-stage ductal carcinoma, a type of breast cancer.

Her diagnosis led to a mastectomy of her left breast and nine months of chemotherapy. Then in 1998 she opted for a prophylactic mastectomy on her right breast and genetic testing on her tumor.

A tough diagnosis

Fast forward to 2011: Bartuska's health was stable, and she was living her life as usual, until she found a lump in her neck.

After a biopsy and PET scan, she was diagnosed with metastatic breast cancer (mBC), which was estrogen receptor-positive (ER+) and HER2-negative (HER2-), the most common form of mBC. This diagnosis came as a shock, because so much time had passed since her initial diagnosis and treatment, and now it had spread to her lungs, bones and sternum.

Bartuska wanted to know how long she was going to live. She started researching mBC and gave herself a pep talk. "If anybody can beat this, I can," she said. "I'm a fighter. I'm an optimist. My cup's always half full."

Initial treatment brings hope

Bartuska responded well to endocrine therapy (ET) for five years, which is a type of treatment that is typically given to people with this form of mBC. Her doctors even considered her as showing "no evidence of disease" (NED) because her tumor responded so well to this treatment.

However, after the five-year mark, Bartuska's cancer markers started rising again. This prompted her doctors to conduct more testing to better understand what was causing her cancer to progress, and to try other treatments. That testing revealed that her tumor had an ESR1 mutation.

What are ESR1 mutations?

ESR1 mutations develop when the cancer changes to try to "outsmart" ET, and they primarily occur as a result of exposure to ET during treatment for mBC. These mutations are common, and up to 50% of ER+, HER2- advanced or metastatic breast cancer tumors will develop these mutations at some point.[i]

Once they develop, ESR1 mutations cause tumors to become resistant to endocrine therapy and can make the cancer cells more difficult to treat, in turn causing the cancer to progress and grow. It is important to note that this mutation is not inherited at birth, and it is not typically present when someone is initially diagnosed with mBC. Instead, the mutation can develop following exposure to ET, so it is important to test for ESR1 each time mBC progresses.

ESR1 mutation testing

The good news is that ESR1 mutations can be detected by a blood test, also called a liquid biopsy. This is also the most effective and accurate method for detecting ESR1 mutations, because the tumor sheds cells into the bloodstream. These cells are not always uniformly present in the tumor tissue, so testing for ESR1 with a tissue biopsy can actually miss the mutation up to 40% of the time.[ii] Therefore, if the test is performed on a tissue sample and leads to a negative result, it is important to follow up with a blood test to double-check for the ESR1 mutation.

Treatment options for those with an ESR1 mutation

The reason that it is important to test for ESR1 each time ER+, HER2- mBC progresses is that this information can play a critical role in treatment planning. This is just what Bartuska experienced. Once her care team found that her cancer had an ESR1 mutation, she was able to take a medicine called ORSERDU^® (elacestrant) that specifically targets this mutation. ORSERDU is approved in the U.S. for the treatment of postmenopausal women or adult men, with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.

"It is so important to ask for an ESR1 test whenever you experience disease progression. And, if you do have the ESR1 mutation, discuss ORSERDU with your care team," said Bartuska. "ORSERDU gave me the hope and the fortitude to go and do things that I love, like riding my motorcycle and spending time with my loved ones."

When ORSERDU was approved in 2023, it was the first innovation in ET for ER+ HER2- advanced or metastatic breast cancer in nearly 20 years. Importantly, it is the only FDA approved treatment that targets tumors that harbor ESR1 mutations, and it delivers longer progression-free survival (PFS) than the standard of care treatment[iii].

ORSERDU is offered in a convenient, oral, once daily dose. In the clinical study of ORSERDU, most side effects were classified as mild to moderate. ORSERDU may cause serious side effects, including increased fat (lipid) levels in your blood, (hypercholesterolemia and hypertriglyceridemia). Your healthcare provider will do blood tests to check your lipid levels before and during your treatment with ORSERDU. The most common side effects that people experience while taking ORSERDU are muscle and joint pain, nausea, decreased appetite, vomiting, constipation, headache, hot flush, tiredness and diarrhea. These are not all the possible side effects; anyone who is considering whether ORSERDU is an appropriate option for them should consult with their doctors for medical advice.

Since taking ORSERDU, Bartuska shared that her outlook on life has improved, and highlights the importance of further disease education. "It's not pink ribbons and bows all the time. We need more awareness that metastatic disease can keep coming back," she explained.

Looking down the road

As Bartuska considers the future, she prioritizes joy and positivity and spends as much time as she can enjoying her family, her friends, and pursuing her hobbies.

"To be honest, half of my life has been consumed with breast cancer, so I don't know what it would have been like to not have this disease," said Bartuska. "I've been on many treatments over the years, and some of the treatments have hindered me so much that I didn't feel well enough to do my day-to-day activities. As much as I focus on the positive and on keeping this cancer at bay, there have been a few times that I've gotten lost in grief thinking 'this is it — I'm not going to pull through this.' But ultimately, I have to remind myself to focus on what and who I love, like the feeling of being outdoors and riding my motorcycle through a beautiful stretch of nature, and then I can get through those dark moments."

"I also focus on encouraging other women who are also fighting this disease by telling them that I've been living with metastatic breast cancer for six years which is much longer than my initial prognosis. That gives hope to them and to their loved ones, and if I can make someone else's day a bit brighter, then I feel happy too," Baruska explained. "I'm just going to keep living my life and doing what I love because I've got today."

Paula is no longer on treatment with ORSERDU but is passionate about continuing to educate others with mBC on ESR1 mutations.

If you or a loved one have metastatic breast cancer, talk to your doctor or visit ESR1TreatmentOption.com to learn more.

ORSERDU^® IMPORTANT SAFETY INFORMATION
ORSERDU may cause serious side effects, including:

• Increased fat (lipid) levels in your blood (hypercholesterolemia and hypertriglyceridemia).

Your healthcare provider will do blood tests to check your lipid levels before and during your treatment with ORSERDU

Before taking ORSERDU, tell your healthcare provider about all your medical conditions, including if you:

• Have liver problems
• Are pregnant or plan to become pregnant. ORSERDU can harm your unborn baby
Females who are able to become pregnant:

• Your healthcare provider may do a pregnancy test before you start treatment with ORSERDU
• You should use effective (contraception) birth control during treatment with ORSERDU and for 1 week after the last dose Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with ORSERDU

Males with female partners who are able to become pregnant:

• You should use effective (contraception) birth control during treatment with ORSERDU and for 1 week after the last dose

• Are breastfeeding or plan to breastfeed. It is not known if ORSERDU passes into your breast milk. Do not breastfeed during treatment with ORSERDU and for 1 week after the last dose

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. ORSERDU and other medicines may affect each other causing side effects. Know the medicines you take. Keep a list of them to show your healthcare provider or pharmacist when you get a new medicine.

The most common side effects of ORSERDU include:

• Muscle and joint (musculoskeletal) pain
• Nausea
• Increased cholesterol and triglyceride levels
• Increased liver function tests
• Tiredness
• Decreased red blood cell counts
• Vomiting
• Decreased salt (sodium) levels in your blood
• Increased kidney function test
• Decreased appetite
• Diarrhea
• Headache
• Constipation
• Stomach-area (abdominal) pain
• Hot flush
• Indigestion or heartburn

Your healthcare provider may decrease your dose, temporarily stop, or completely stop treatment with ORSERDU, if you develop certain side effects.

ORSERDU may affect fertility in males and in females who are able to become pregnant. Talk to your healthcare provider if this is a concern for you.

ORSERDU is available as 345 mg and 86 mg tablets.

These are not all the possible side effects of ORSERDU. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088 or visit www.fda.gov/medwatch.

Please see important facts about ORSERDU on ORSERDU.com

By Menarini Stemline