Promising Drugs to Treat and Manage Chronic Hyperkalemia?

Promising Drugs to Treat and Manage Chronic Hyperkalemia?

For the past 50 years, Health Care Practitioners – namely cardiologists and nephrologists – have had limited options to manage chronic hyperkalemia. The focus has been on emergency and transient care mostly due to the lack of viable therapies for recurrent HK.

Hyperkalemia is a common condition in patients suffering from Chronic Kidney Disease (CKD): our studies show that up to 30% of CKD patients suffer from hyperkalemia. The fact that the risk of HK is increased in patients with Congestive Heart Failure (CHF) has been a serious concern for physicians who have had no choice but to discontinue RAAS inhibitors (beta blockers, renin inhibitors, ACE inhibitors, ARBs and aldosterone inhibitors) or allow only less than optimal doses.

New Potassium Binders to Manage Chronic Hyperkalemia

Two new drugs are closely watched for their potential to effectively manage the condition.

Veltassa® (Patiromer)

Developed by Relypsa, Inc. and approved by the FDA in October 2015, Veltassa is the first drug since 1958 specifically designed to treat hyperkalemia.

While the drug is made available to hospitals, Relypsa’s CEO John A. Orwin sees “the bigger opportunity in the chronic outpatient setting”. Our Hyperkalemia PROfiler, compiling results from studies with CKD patients and their HCPs from the nephrology and cardiology area, may confirm those premises.

Though still in its early days on the market, Veltassa is expected to be welcomed by doctors, as it may finally meet the need to treat patients with chronic hyperkalemia, and most importantly patients with concomitant kidney disease and congestive heart failure.

ZS-9 (Sodium Zirconium Cyclosilicate)

ZS-9 is another potassium binder, developed by ZS Pharma (a whole subsidiary of AstraZeneca). The hyperkalemia drug has been rejected by the FDA in May due to manufacturing concerns (the new drug is currently under review in Australia and the European Union). ZS Pharma re-submitted a NDA (New Drug Application) in October.

Both drugs appear to be promising compounds that will help patients attain and maintain normokalemia. Other positive effects include efficacy with heart failure medications, reducing aldosterone levels and blood pressure.

Evidence Gaps

Those 2 new drugs will require close qualitative monitoring and tracking, both from a prescription and administration standpoint.

What has yet to be addressed are the potential effects of drug-drug interaction. Veltassa is reported to bind with many other drugs and should be taken 6 hours before or after. This could cause a problem for CKD/CHF patients who are no strangers to multiple daily prescriptions and may not be willing to continue the therapy.

ZS-9, exchanging potassium for sodium, may also pose a risk for patients treated for high blood pressure.

In both cases, long term safety studies are needed to assess the risks of taking the drugs and the risks of discontinuing them (rebound hyperkalemia).

Another question regarding those new strategies to treat chronic hyperkalemia is the potential limitation of RAAS inhibitors should they provoke hypotension or if the renal function was to worsen. It is also unclear whether patiromer can be prescribed to all with recurrent hyperkalemia, as the clinical trials excluded certain groups of patients *.

Conclusion

The introduction of new drugs to help manage chronic hyperkalemia and RAASi optimization is a step in the good direction. But how will nephrologists and cardiologists embrace new treatment strategies? To what extent will Relypsa and ZS Pharma have to identify and educate specialists who really manage the condition in CKD and CHF patients?

Long term HK management will have a strong impact on market size and the economic success of new drugs. The two companies are expecting sales anywhere between $200 millions and 1-2 billion of a market that could be worth $6 billion.

HCPs are expecting to ultimately be able to efficiently manage chronic hyperkalemia.
Patients are expecting improved quality of life and increased life expectancy.
Needless to say we will closely watch Veltassa and ZS-9.

*Patients were excluded from this study if potassium-related electrocardiogram changes were observed and if they had severe GI disorders, kidney or heart transplantation, recent acute coronary syndrome, transient ischemic attack or stroke within the prior 2 months, type 1 diabetes, uncontrolled arrhythmias, uncontrolled hyper- or hypotension, recent emergency treatment for diabetes or heart failure within the prior 3 months, or New York Heart Association class IV heart failure.* Source Journal of Pharmacy Practice I-5

Contact us if you want to know more about our hyperkalemia and hyperphosphatemia PROfilers.