There may be a bootleg PDF floating around somewhere, but it is not easily available. Better to support the work of scholars and purchase the book.
Pali Text Society books can usually be purchased online directly from the Society.
and scroll down to:
The Summary of the Topics of Abhidhamma and Exposition of the Topics of Abhidhamma,
tr. R.P. Wijeratne & Rupert Gethin, 2002