Unexpected Result for address in New Zealand

[mtrappschuh]

Given street:
D/5 The Esplanade
(Full Address: D/5 The Esplanade, Eastern Beach, Auckland 2012)

Current result:
array ( 'additionToAddress1' => '', 'streetName' => 'D/', 'houseNumber' => '5', 'houseNumberParts' => array ( 'base' => '5', 'extension' => '', ), 'additionToAddress2' => 'The Promenade', )

Expected result:
array ( 'additionToAddress1' => 'D/', 'streetName' => 'The Promenade', 'houseNumber' => '5', 'houseNumberParts' => array ( 'base' => '5', 'extension' => '', ), 'additionToAddress2' => '', )

The comma in the following line is breaking the expected result:
(?:(?P<A_Addition_to_address_1>.*?),\s*)? # Addition to address 1

[svenmuennich]

Test data:

[
    'D/5 The Esplanade',
    [
        'additionToAddress1' => 'D/',
        'streetName' => 'The Promenade',
        'houseNumber' => '5',
        'houseNumberParts' => [
            'base' => '5',
            'extension' => '', 
        ],
        'additionToAddress2' => '',
    ]
]