Joint inventorship clarified

Pursuant to 35 USC § 116(a), "[i]nventors may apply for a patent jointly even though (1) they did not physically work together or at the same time, (2) they did not make the same type or amount of contribution, or (3) they did not make a contribution to the subject matter of every claim of the patent. In Dana-Farber Cancer Institute, Inc. v. Ono Pharmaceutical Co., LTD (Fed. Cir. July 14, 2020), the Federal Circuit considered the contribution required to be a joint inventor.

In the early 1990s, Dr. Tasuku Honjo discovered PD-1, a protein found on T cells, a type of immune cell, that regulates body's immune system. Then around 1998, Drs. Honjo, Wood, and Freeman collaborated and exchanged information on cancer treatment research. The following year, Drs. Wood and Freeman filed a provisional patent application disclosing modulation of an immune response via activating or blocking the PD-1/PD-L1 pathway, but did not include Dr. Honjo as an inventor. In March and April 2000, Drs. Honjo, Freeman, and Wood co-authored an article documenting their discoveries concerning PD-L1, which revealed that some tumors may use PD-L1 to inhibit an immune response. In June 2000, Dr. Honjo learned of the 1999 provisional application, and he later unsuccessfully sought to be included as a co-inventor on the application.

By the time the article was published in October 2000, Dr. Honjo had stopped sharing information with Drs. Freeman and Wood. Around this time, Dr. Honjo received data from knockout (genetically modified) mice experiments that led to conception of the claimed inventions. Drs. Freeman and Wood did not participate in these experiments. The inventions generally relate to methods of treating cancer using PD-1 or PD-L1 blocking antibodies to block the PD-1/PD-L1 pathway, thereby permitting T cells to activate an immune response, and the immune system to attack cancer cells. In 2002, Dr. Honjo filed his own patent applications in Japan, disclosing results from the knockout mice experiments. The patent applications did not mention PD-L1 in the claims, and did not include Drs. Freeman and Wood as joint inventors.

In 2015, Dana-Farber, the assignee of Dr. Freeman's rights as an inventor, sued Ono Pharmaceutical, alleging that Drs. Freeman and Wood should be added as inventors on Dr. Honjo's patents. The district court considered contributions from Drs. Freeman and Wood and held that they must be included as co-inventors.

On appeal, Ono Pharmaceutical argued that the doctors' contributions were too far removed from the claimed subject matter of the patents. But the Federal Circuit disagreed stating, "the statute and our case law make clear that joint inventors need not contribute to all aspect of a conception… That Drs. Freeman and Wood were not present for or participants in all the experiments that led to the conception of the claimed inventions does not negate their overall contributions throughout their collaboration with Dr. Honjo."

Ono Pharmaceutical also argued that "work from Drs. Honjo, Freeman and Wood's collaboration was too speculative until the October 2000 knockout mice studies." The Federal Circuit disagreed stating, "conception is complete when an idea is definite and permanent enough that one of skill in the art could understand the invention… Moreover, the record is clear that Dr. Iwai's work was conducted after Dr. Freeman had shown expression of PD-L1 in human tumors and Dr. Honjo had shown that PD-L1 expression causes tumor growth, so as a factual mater, PD-L1's potential utility in treating human cancer was developed jointly with Dr. Freeman before Dr. Iwai's work."

Ono Pharmaceutical argued that the patents were issued over the 1999 provisional application filed by Drs. Freeman and Wood, so their contributions were not significant to Dr. Honjo's patents. The Federal Circuit disagreed stating, "[c]ollaboration and concerted effort are what result in joint inventorship… The novelty and nonobviousness of the claimed inventions over the provisional application are not probative of whether the collaborative research efforts of Drs. Honjo, Freeman, and Wood led to the inventions claimed here or whether each researcher's contributions were significant to their conception."

Finally, Ono Pharmaceutical argued that Drs. Freeman and Wood's contributions cannot qualify as a significant contribution to conception because their contributions were published before conception of the invention. The Federal Circuit again disagreed stating, "[i]nventorship of a complex invention may depend on partial contributions to conception over time" and "publication of a portion of a complex invention does not necessarily defeat joint inventorship of that invention."

This case illuminates the significant range of factual scenarios that may support joint inventorship under 35 USC § 116(a) by recognizing that: 1) joint inventors need not contribute to all aspect of conception; 2) a joint inventor's contribution to conception need not be validated or verified at the time of the contribution; 3) whether the invention as a whole is novel or non-obvious over a prior art contribution of a joint inventor is not probative of whether the joint inventor's contributions were significant for purposes of determining joint inventorship; and 4) publication of joint inventor's contribution does not negate joint inventorship.