Does Arbutus’ patent suit against Moderna’s Covid vaccine have a testing problem?

Zachary Silbersher

I’ve blogged several times about the ongoing patent dispute between Arbutus and Moderna.  The case is nearing the end of expert discovery and is headed for trial towards the end of 2025.  A recent discovery dispute between the parties highlighted an important issue to watch as the case nears trial.  The dispute concerns Arbutus’ testing of Moderna’s vaccine—Moderna claims that the parameters used to setup the testing may have been faulty.  Does Arbutus have a testing problem, or Moderna grasping for straws in the face of troubling test results?

At a hearing on May 7 before the Honorable Mitchell S. Goldberg, the parties discussed prospective summary judgment and Daubert motions.  (A Daubert motion allows an opposing party to essentially stress test of an expert’s reliability before the expert testifies to the jury.)   Judge Goldberg proposed the parties narrow the issues so that only worthwhile summary judgment and Daubert motions would be filed.  The takeaway, however, was clear that the case is unlikely to be disposed of on summary judgment, and it is very likely going to trial.  The trial date is currently scheduled for late September 2025.  Judge Goldberg remarked, however, that given the workload in advance of trial—including work required for the court to review and decide even limited summary judgment and Daubert motions—the current trial date is likely to be extended.  To its credit, Arbutus emphatically argued that it can be ready for trial in September, but Judge Goldberg indicated the trial date is still likely to be continued. 

Meanwhile, an important discovery dispute was discussed.  By way of brief background, Arbutus has asserted multiple patents directed to nucleic-acid lipid particles that recite multiple ingredients with mol percentages.  (One example patent is the ‘069 patent.)  Moderna produced multiple samples of its Covid vaccine during discovery, and Arbutus retained an analytical chemist expert to run tests on those samples.  In particular, the expert used a centrifuge to spin the samples at high speeds that separated out the sample’s respective ingredients. The expert then interrogated those individual ingredients to purportedly determine each ingredient’s respective mol percentage. 

The parties are nearing the end of expert discovery, and have already deposed most, if not all, of the experts.  The dispute arose out of a deposition by Moderna of Arbutus’ analytical chemist expert.  Moderna claims that, during this deposition, it learned for the first time that Arbutus’ expert had run preliminary tests to determine the protocol for testing the samples.  Moderna claims that none of the facts and documents regarding this preliminary testing was disclosed to Moderna.  For instance, documents concerning the storage of the samples before and during testing were not disclosed, which is potentially important since Moderna’s vaccine must be stored at extremely low temperatures.  Moderna suggested that if the samples were improperly handled, that could corrupt the final test results.  In a somewhat precipitous move, on April 24, Moderna fired off an emergency motion seeking to compel immediate discovery from Arbutus.

During the hearing on May 7, the parties appeared to reach general agreement that Arbutus would produce facts, images and documents related to the preliminary protocol testing.  In that sense, the discovery dispute itself is likely to be resolved.  Yet, the dispute itself is potentially telling of an important defense Moderna may use at trial against Arbutus’ claims in this case. 

Beyond complaining that Arbutus simply failed to hand over documents that should have been produced, Moderna is also suggesting that Arbutus’ testing was flawed.  It claims that the protocol used to set up the testing of the vaccine samples can affect or change the ingredients, and potentially change the mol percentages of the ingredients.  A number of parameters had to be decided for how to run the testing.  As an example, the speed of the centrifuge could be one such parameter, and Moderna is suggesting that if the speed parameter was incorrect, it could essentially corrupt the ultimate results.   

Does this bode well for Arbutus or Moderna?  On the one hand, Arbutus has to prove that the Moderna’s vaccine satisfies the mol percentages recited in the patents.  If Moderna is concerned that Arbutus’ testing has accomplished that, then Moderna’s alternative course may be to attack the testing protocol and argue that the testing was flawed.  If Moderna can successfully attack the protocol as improper, that could convince the jury that the testing results themselves were flawed.  For its part, Arbutus has claimed that the testing protocol was routine and standard and there was nothing faulty about it.  In fact, Arbutus ran separate tests to confirm that the process of spinning the samples did not actually destroy or change the ingredients themselves.

On the other hand, the results of Arbutus’ testing are themselves not public, and therefore, we cannot know what they say.  It is not uncommon for a defendant to pursue multiple possible defenses, asserted in the alternative, in parallel.  That’s the way litigation works.  In other words, even if Arbutus’ test results don’t do enough to show infringement, Moderna would still likely launch an attack on the testing protocol itself.  During the May 7th hearing, the Judge asked Moderna if it will be challenging the actual test results themselves, and Moderna confirmed that it would.  That said, emergency discovery motions are not that common.  So whether that was a tell or not remains to be seen.

It is not uncommon for parties to litigate dozens of discrete issues during discovery, but drop many of them as they get closer to trial.  Judge Goldberg appears to be imposing upon the parties to do that in this case.  And Arbutus itself has acknowledged that narrowing the case is likely necessary.  For instance, Arbutus is supposedly asserting approximately 66 different patent “claims,” (each patent has several individual “claims”), and Moderna is supposedly asserting thirty-three separate Section 112 defenses.  (There appears to be a dispute over how to count the defenses.)

Given all of this, if the parties do successfully narrow the issues to be heard at trial, then the main issues over which this case will be decided are likely to come into view in the next few weeks.  One of these issues may pit a battle of the experts over Arbutus’ testing of Moderna’s vaccine samples.  Letters proposing how to narrow the case are scheduled to be filed by May 13.