Is the Revolutionary New Late-Stage Breast Cancer Drug, Enhertu®, Beneficial in a South African Context?

Social media has been buzzing with news of the revolutionary new breast cancer drug, Enhertu®, and how it will be able to extend and enhance the lives of late-stage and metastatic breast cancer survivors. Make no mistake, this is great news but, in a South African context, how beneficial is Enhertu® really?


More About Enhertu®

Enhertu®, developed and researched by Daiichi Sankyo and the pharmaceutical company, AstraZeneca, is an antibody-drug conjugate. This means that an antibody zones in on tumour cells before delivering destructive chemotherapy to attack and kill the cells themselves. With Enhertu®, the cells targeted are proteins known as HER2, a receptor that normally controls the way that healthy breast cells grow and repair. On occasion, in about a quarter of breast cancers, this HER2 receptor mutates, which causes cells in the breast to grow and divide at an uncontrolled rate. This, in turn, leads to and assists tumour growth. These tumours are known as HER2-positive tumours.

Benefits

AstraZeneca and Daiichi Sankyo’s trial of Enhertu®, dubbed DESTINY-Breast04, showed a 72% reduction in the risk of HER2-positive and HER2-low cancer progression or death in late-stage, metastatic breast cancer patients. HER2-positive breast cancers make up 25% of all breast cancers worldwide. Another 30% carry the HER2 receptor. With Enhertu®, medical oncologists will also be able to treat patients with a lesser amount of HER2 cells (dubbed HER2-low), thus increasing the percentage of patients who could benefit.

A study involving five hundred HER2-low breast cancer patients was conducted in the US recently. It drew comparisons between Enhertu® and standard chemotherapy. These patients’ cancers had metastasized or could not be treated surgically. During and after the Enhertu® treatment, cancer progression stopped for around 10 months compared with about 22 weeks after regular chemotherapy. Enhertu® also extended survival rates from 17.5 months to 23.9 months.

Side-Effects

A major pitfall remains the drug’s chemical toxicity levels, however. It is important to realise that Enhertu® is likely to be used after the use of more established HER2 targeted treatment like Trastuzumab which, in itself, has side-effects that can be long-lasting. Enhertu® carries all of the side-effects that could be experienced in standard chemotherapy and more. In the same US study already mentioned, three patients died from Interstitial lung disease, a known side-effect of Enhertu®. The drug is also known to cause heart problems.


Enhertu® in a South African Context

CopyFounder recently held a brief discussion with Salomé Meyer, Project Manager of the Cancer Alliance’s Access to Medicine Campaign, to ascertain what Enhertu® could mean in a South African context.

Price

Not even in the US will it be affordable. In South Africa, only 10% of people who access private healthcare, 16% of the total population, have access to high cost oncology medicines. That should describe the inequity of our healthcare system!

Salomé Meyer, Cancer Alliance

For a pharmaceutical product to be truly beneficial in the South African market, it needs to be affordable. On the US market, Enhertu® costs $2562.50 per 100mg of intravenous powder for injection. So, if a patient weighs 70kg, your dose of Enhertu® would be 378 mg. At the current Rand-Dollar exchange rate this means the patient (or medical aid) would have to cough up R151323.44 per dose. When you add the 15% import costs, this price rises to R174021.96 per dose.

Enhertu® needs to be administered every three weeks until a patient can no longer tolerate it, which means that, for the drug to be beneficial, a substantial amount of money will need to be spent. Even six months of Enhertu® treatment would amount to over R1.5 million per patient.

In a nutshell, for all of the health benefits that Enhertu® could provide to South African late-stage breast cancer patients, it is simply not affordable for the vast majority of them, and won’t be for a long time.  In essence, it is only a beneficial drug for the rich and famous.

Emphasis for Targeted Therapy

The HER+ number of patients is relatively small in South Africa – about 20% of breast cancer patients. The research to get such targeted therapy in place is great, but do we need that for advanced cancers? Rather do research for early stage cancers, in my humble opinion. We need to fix our own health system to ensure that people are diagnosed earlier, which will have better outcomes that will be more affordable.

Salomé Meyer, Cancer Alliance

The percentage of South African breast cancer patients carrying the HER2 receptor is far lower than the international average, which means that the need for the drug is not as high as in certain other countries. With that in mind, and the extravagant pricing of Enhertu®, it makes more sense for government and local pharmaceutical companies to invest in fixing the South African health system, which would help with the early diagnosis and treatment of cancers, and with providing affordable drugs that will benefit patients.

Patents

Under the current patent law in SA this drug will remain unaffordable and inaccessible for most South Africans. We need patent law reform.

Salomé Meyer, Cancer Alliance

Patents have, for too long, been a deciding factor in preventing affordable healthcare in South Africa. Activists have been demanding that the government provide strict examination of all pharmaceutical product patents so that they aren’t automatically granted, especially for life-saving medicines. These patents are effectively limiting the supply and drastically inflating the prices of these types of medicine.

Currently, when a medical product is under a pharmaceutical company’s patent, it can charge and adjust its chosen price for a twenty year period. As the product is under patent, there can be no competition from other products, thus keeping the cost of the medicine inflated.

According to the Fix the Patent Laws campaign, South Africa has a depository system for patents. This means that patents are not examined by specialist examiners for secondary patents. Many of the lifesaving medicines will then remain out of reach for patients for longer than the intended twenty year period.

International law provides legal safeguards which South Africa has not adopted as yet. Section 27 of the Constitution of South Africa actually obligates the state to implement such law reforms, which would see improved access to lifesaving medicines for cancer and other diseases. As things stand, South African patent laws ensure that Enhertu® will remain inaccessible to the majority of those who truly need it for a long time.


Conclusion

Although Enhertu® is deserving of its revolutionary status, and all of the positive social media it is receiving, research into what isn’t being said indicates that, in a South African context, the drug is not likely to hold much benefit for local breast cancer survivors.

The drug’s extreme price, coupled with its local target market and South Africa’s inflexible patent laws, mean that this impression is unlikely to change for many years.

The South African government needs to be encouraged to implement change that can alter the current status quo to make targeted therapies more accessible to all cancer patients by amending the patent laws and updating its exclusionary cancer policies in ways that will benefit individual cancer patients and provide them with the treatment they require and deserve.

Enhertu® has not yet been approved by SAHPRA for use in South Africa.

(Cover image courtesy of the Chicago Sun Times)

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