Hello
there is few third party produc like skype shield to provide MDM or MAM for Lync but this will cost much more than Azure AD integration/intune and they are much more complex to deploy and support.
Please note that even intune still not fully support lync for MAM and conditional access if you use lync on prem or you are in hybrid because one main requirement for both is Modern authentication which only supported for skype for business online
for the moment. // this may change by the end of the year.
for reference
modern authentication for Lync https://support.microsoft.com/en-gb/kb/3126604
Note: MAM without device enrollment and conditional access functionality require modern authentication to be enabled for Skype for Business Online, and it is currently
disabled by default. Follow
these instructions to enable it. An upcoming update will let you manage it directly from the Office 365 admin console.
for reference
https://blogs.office.com/2016/04/28/mobile-application-management-and-conditional-access-now-available-for-skype-for-business-online-with-intune/
https://docs.microsoft.com/en-us/intune/deploy-use/restrict-access-to-skype-for-business-online-with-microsoft-intune
you may think also to use different client for users than Lync client like blackberry(Good) connect which will be linked to Lync infrastructure and will stop any data
leakage.
