H1B question

1.5 year ago, a company applied a H1B visa for me. While it was pending, I accept a job for a non-profit institute and got a H1B visa later. Recently I accpet a new job from another company. Now my question is, can I do H1B transfer? Today I checked the status of the pending H1B visa, it is still pending, asking for reference evidence.

Thank you very much!