PHP/MySql search array with array

I'm building a WordPress website.

With a MySql Query I load all companies from my database that have a specific brand:

$results = $wpdb->get_results("SELECT * FROM $wpdb->postmeta WHERE meta_key = 'brand'")`

brand is an array so I search for a specific value in array:

$brand = $_GET['brand'];
$brandNeedle = $brand;

if(in_array($brandNeedle, $brand[0]))

Now, my client asked to list all users that are connected to all those companies that are selected.

So I need to create a new query. Fortunately the users all have a field added to their colum that tells me where they are working.

So I thought: what if I create a array that holds all companynames that are queried from the companylist.

With this array I can select all users who have the company name in their column

So I think the query should be something like this:

SELECT * FROM $wpdb->usermeta WHERE meta_key='company' AND meta_value ='THE ARRAY'

But this doesn't work obvious because it can't search with an array in an array.

I can't seem to figure it out. Any ideas?

-- EDIT --
Okay so I did the implode function and I do something wrong:

$brand_array = array();
for($i=0; $i <count($results); $i++){
    $result = $results[$i]; 
    if ($i % 2 == 0){
        $oddeven = 'even';
    }else{
        $oddeven = 'odd';
    }
    $post_id = $result->post_id;
    $company_name = get_post_meta($post_id, 'company_name', true); 
    $brand_array[] = $company_name;
}
    print_r($brand_array);
    $imploded = implode(',',$brand_array);

    $query = "SELECT * FROM $wpdb->usermeta WHERE meta_key='company' AND meta_value IN $imploded";
    $persons = $wpdb->get_results($query);

This gives me the results I need (the two companies in a new array) and gives me the following error:

WordPress database error: [You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near
'brand1,brand2' at line 1]
SELECT * FROM wp_usermeta WHERE meta_key='company' AND meta_value IN
brand1,brand2