Correspondence | Published:

Patent dispute hangs over kringle 5

Nature volume 407, page 128 (14 September 2000) | Download Citation


Sir — In June you published a News brief relating to a suit brought by Abbott Laboratories against Children's Hospital in Boston and against me and two of my younger associates1. The suit asserted rights to a patent assigned to Children's Hospital on an endothelial and angiogenesis inhibitor called kringle 5 which was discovered in the hospital's laboratories.

Abbott's claim is limited to one small aspect of Children's Hospital work, not involving any work on angiogenesis or the discovery of the angiogenesis inhibitors angiostatin, endostatin, or others.

If an academic institution wants to see its laboratory discoveries translated to the bedside, it must seek patents. Patent disputes, unfortunately, are not unusual. What is unusual here is that Abbott Laboratories, in a deliberate attempt to claim for itself a discovery that it neither made nor owns, has attacked the integrity of scientists at Children's Hospital and has publicized its false allegations worldwide.

I have no personal financial interest in this matter. My only objective is to see that medical advances are brought to clinical application so that patients can benefit. It will be reprehensible if Abbott's actions disrupt or delay this.

Abbott's claims against Children's Hospital, me and my associates are false and malicious. The truth of the matter is as follows. First, Abbott based many of its claims in court on an alleged confidentiality disclosure agreement and attached the agreement as a key part of its court filings. The alleged agreement was originally sent to Children's Hospital in June 1995, but it was never agreed to by the hospital nor returned to Abbott. The hospital's Office of Technology rejected the sweeping agreement. A technology office official wrote many comments on the document and in July 1995 told Abbott and its employee Donald Davidson that the agreement was unacceptable. He forwarded to Abbott an alternative agreement, but Abbott never signed it.

Second, five months later I received a letter from Abbott clearly acknowledging the lack of any agreement with Children's Hospital and proposing that, in the absence of a legal agreement, we enter into a “gentlemen's agreement” whereby Abbott would provide plasminogen fragments in exchange for my laboratory continuing to provide Abbott with expertise and materials. Abbott also proposed that Davidson and another Abbott employee visit my laboratory to learn more. I informed Abbott that we did not wish their employees to visit, but that we would be happy to share our expertise and cell lines with Abbott, which we did.

Third, Davidson was working on the thrombolytic (clot lysing) properties of plasminogen and had no idea that any fragment of plasminogen had anti-endothelial or anti-angiogenic activity until after my laboratory published the discovery of angiostatin in Cell2 in October 1994, six months after Yihai Cao in my laboratory first requested plasminogen fragments from Davidson and other scientists, including Miguel Llinas of Carnegie Mellon University and Stephen McCance of American Biogenetic Sciences and Notre Dame.

Fourth, the anti-endothelial and anti-angiogenic properties of various kringle fragments of plasminogen were discovered by Cao, Michael O'Reilly and me. Cao and O'Reilly were postdoctoral fellows in my laboratory at Children's Hospital.

Fifth, Cao published two papers on his results3,4. He graciously included Davidson, McCance and Llinas as co-authors because they supplied plasminogen fragments or advice on preparing those fragments.

Last, on 18 July 2000, Children's Hospital filed a detailed answer and counterclaims, and on 14 August, Abbott filed a pleading in court admitting that it had doctored the alleged agreement it had attached to its complaint.


  1. 1.

    Nature405, 608 (2000).

  2. 2.

    et al. Cell 79, 315–328 (1994).

  3. 3.

    et al. J. Biol. Chem. 271, 29461– 29467 (1996).

  4. 4.

    et al. J. Biol. Chem. 272, 22924– 22928 (1997).

Download references

Author information


  1. Children's Hospital, 300 Longwood Ave , Boston, Massachusetts 02115, USA

    • Judah Folkman


  1. Search for Judah Folkman in:

About this article

Publication history




By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Newsletter Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing