const transformedResponse = transformResponse(response);
  const loggerResponse = transformedResponse.map(
      ({drugName, mailPrice.copayEmployer, ...rest}) => rest
  );

[{
        "isBrand": true,
        "drugName": "Lipitor",
        "drugStrength": "80 mg",
        "drugForm": "Tablet",
        "mailPrice": {
            "copayEmployer": 0
        }
    }, {
        "isBrand": true,
        "drugName": "Metformin",
        "drugStrength": "500 mg",
        "drugForm": "Tablet",
        "mailPrice": {
            "copayEmployer": 50
        }
    }

]

.map(({ drugName, mailPrice: { copayEmployer }, ...rest }) => rest);