Orserdu (elacestrant)
Orserdu is approved for the treatment of advanced breast cancer in postmenopausal women, and men. Orserdu contains the active ingredient elacestrant.
Orserdu is an anticancer medicine for the treatment of postmenopausal women, and men, with locally advanced or metastatic breast cancer (cancer that has spread to other parts of the body).
Orserdu is for use only in patients whose cancer cells:
- have oestrogen receptors (ER‑positive)
- do not have high levels of the human epidermal growth factor receptor 2 protein (HER2‑negative)
- have specific mutations (changes) in the ESR1 gene, the gene which makes oestrogen receptors. ESR1 mutations allow cancer cells to become resistant to anticancer drugs.
Orserdu is for the treatment of patients whose disease has not responded to, or has progressed, following at least one previous hormone‑based therapy, including treatment with a cyclin‑dependent kinase (CDK) 4/6 inhibitor (another type of anticancer medicine).
Some breast cancers develop because the hormone oestrogen stimulates them to grow and survive. Oestrogen works by attaching to oestrogen receptors on cancer cells.
Orserdu is designed to:
- block the binding of oestrogen to the oestrogen receptor
- facilitate the degradation of oestrogen receptors on the surface of cancer cells.
This reduces the number of working oestrogen receptors, which in turn reduces the ability of oestrogen to cause cancer growth.
Orserdu has the advantage of being an oral medicine, allowing patients to manage their treatment at home and eliminating the need for repeated injections.
The effectiveness and safety of Orserdu were assessed in a clinical study involving 478 participants with ER-positive/HER2-negative advanced breast cancer whose disease had returned or progressed after hormone therapy.
The study compared Orserdu with standard of care (SOC), the most effective treatment currently available for this type of breast cancer, and participants with ESR1 mutations were included in both groups.
Key findings from the clinical study
- The study showed a significant improvement in progression-free survival (PFS) in the Orserdu group. PFS is the length of time during and after treatment that a patient lives with the cancer without it getting any worse. In the overall study population, the cancer stayed stable for 2.8 months in the Orserdu group versus 1.9 months in the SOC group.
- The greater benefits seen in the Orserdu group were largely due to participants with the ESR1 mutation. For patients with this mutation, Orserdu significantly improved PFS (averaging 3.8 months compared to 1.9 months on SOC). It reduced the risk of the cancer progressing or death by 45%. This effect was not observed in the SOC group, hence why Orserdu is only approved for people whose tumour has an ESR1 mutation.
- The adverse events caused by Orserdu were similar to that of other hormone therapies, However, patients taking Orserdu experienced nausea and vomiting more often than those on standard of care treatments.
- Other common side effects included fatigue, joint pain, increased cholesterol, indigestion, constipation, headache, hot flushes, abdominal pain, back pain, diarrhoea, increased triglycerides, decreased calcium, decreased appetite, increased creatinine, decreased sodium, decreased potassium, and reduced levels of red blood cells. Serum liver enzymes were also increased. Most side effects were mild to moderate, and the recommended dose was generally well tolerated with supportive care. Overall, Orserdu had manageable side effects.
The TGA decided that the application provided sufficient evidence supporting the safety and effectiveness of Orserdu and the medicine can be registered in Australia.
More detailed information on why the TGA approved Orserdu will be published in the upcoming Australian Public Assessment Report (AusPAR).
For comprehensive information on potential side effects and risks, refer to the Consumer Medicine Information (CMI) leaflet or Product Information (PI) document.
This decision summary will not be updated to reflect any subsequent changes and may therefore not contain the most current information about the medicine. For the latest information, refer to the medicine’s CMI or PI.
The CMI leaflet offers guidance for consumers to support safe and effective use of the medicine. The CMI includes information on dose, how to use the medicine properly, potential side effects, safety precautions, storage instructions and more.
The Australian CMI for Orserdu can be accessed through the searchable TGA eBusiness Services or ARTG databases.
The PI document provides essential prescribing information for health professionals, including details on dosage recommendations, pregnancy category, contraindications, precautions and potential side effects.
The Australian PI for Orserdu can be accessed through the searchable TGA eBusiness Services or ARTG databases.
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