Use a text editor to edit the "ENGINE_SETTINGS.XML" file in the directory. "\Steam\SteamApps\common\Alien Isolation\DATA". Locate the following lines.

[Setting name="ShadowMapResolution"]
[!-- resolution in pixels. --]
[Quality name="512" int="512" precedence="1"/]
[Quality name="1024" int="1024" precedence="2"/]
[Quality name="1536" int="1536" precedence="3"/]
[Quality name="2048" int="2048" precedence="4"]
[DefaultRequirements]
[WindowsExperienceIndex type="GPU" value="7.6"/]
[/DefaultRequirements]
[/Quality]
[/Setting]

...and change them to:

[Setting name="ShadowMapResolution"]
[!-- resolution in pixels. --]
[Quality name="2K" int="2048" precedence="1"/]
[Quality name="4K" int="4096" precedence="2"/]
[Quality name="8K" int="8192" precedence="3"/]
[Quality name="16K" int="16384" precedence="4"]
[DefaultRequirements]
[WindowsExperienceIndex type="GPU" value="7.6"/]
[/DefaultRequirements]
[/Quality]
[/Setting]