Why is Neprilysin Inhibitor Not used Alone

In ARNI (Angiotensin receptor blocker+ neprilysin inhibitor), why is ARB combined with the neprilysin inhibitor? To be exact, what is the disadvantage of giving neprilysin inhibitor alone?
Neprilysin is a neutral endopeptidase involved in the degradation of natriuretic peptides (A, B and C), bradykinin, adrenomedullin, angiotensin II and other vasoactive peptides.
If neprilysin inhibitor is used alone, it will not be effective as angiotensin II levels will rise.
Combining neprilysin inhibitor with angiotensin converting enzyme inhibitor showed superior efficacy but was associated with serious angioedema.
ARNI valsartan/sacubitril does not inhibit angiotensin converting enzyme inhibitor or aminopeptidase P and was not associated with increased risk of angioedema in the PARADIGM-HF trial.
Omapatrilat, a drug which inhibits all the three enzymes involved in degradation of bradykinin (neprilysin, ACE and aminopeptidase P) was associated with serious angioedema and drug development was discontinued.

[@Sickdude420]

Thank you very helpful for cardiology residents !

[@JohnsonFrancisMBBSMDDM]

Glad it was helpful!