On March 21, 2017, the PTAB refused to cancel claims of a Biogen MA Inc. (Biogen) patent covering multiple sclerosis drug Tecfidera^® during IPR2015-01993, which was instituted in response to a petition filed by the Coalition for Affordable Drugs V LLC (CFAD), a group started by hedge fund manager Kyle Bass.

Biogen’s U.S. Pat. No. 8,399,514 claims methods of treating patients for multiple sclerosis (MS). Each claim requires the administration of a dose of about 480 milligrams (mg) per day of dimethyl fumarate (DMF), monomethyl fumarate (MMF), or their combination. CFAD argued that a combination of several prior art references renders obvious all claims of Biogen’s patent. Generally, this combination of prior art describes results from administering 120, 360 and 720 mg/day of DMF to MS patients, but do not disclose the claimed dose. The 720 mg/day dose was reported to reduce brain lesions in a dose-dependent manner, while the 120 and 360 mg/day dose did not show statistically significant results versus placebo. CFAD nevertheless argued that a person of ordinary skill in the art would have been motivated to conduct routine experiments to optimize the effective dose and ultimately arrive at the dose recited in the claims.

Biogen submitted testimony from three experts as well as post-filing Phase III clinical trial data. Biogen argued that the magnitude of the clinical efficacy exhibited by administering the 480 mg/day dose was unexpected. During the trials, MS patients were treated with both 480 and 720 mg/day of DMF. The data obtained from those trials, according to Biogen, established surprisingly that a 480 mg/day dose of DMF proved to have similar efficacy to the 720 mg/day taught by the prior art for almost every end point measured. In response to Biogen’s assertion of unexpected results, the PTAB noted CFAD’s a single-sentence response that  “… success was expected, not unexpected” was unpersuasive, and further noted that:

Biogen’s argument, however, is not merely that it would have been unexpected that some lower doses would have been an effective therapeutic treatment. Rather, Biogen’s position is that the magnitude of the clinical efficacy at the specifically claimed dose of about 480 mg/day would have been unexpected. Petitioner has not directed us to evidence, or provided a reason, for us to doubt the unrebutted testimony of Biogen’s highly qualified and credible experts. Biogen’s expert testimony on this point stands unchallenged. [Decision at 25]

In view of the lack of evidence rebutting Biogen’s testimony, the Board concluded that CFAD failed to establish that the subject matter of the 5’14 claims would have been obvious:

However, as noted above, the testimony of Biogen’s experts, [] persuade us that the magnitude of clinical efficacy of the 480 mg/day treatment would have been unexpected by those working in the art. We conclude, therefore, that the treatment of MS patients with 480 mg/day of DMF would not have been obvious. [Id.]

This blog has reported on the ongoing saga of CFAD petitions at the PTAB. As of this final written decision, the CFAD has been successful in invalidating claims in only 27% of the inter partes review petitions it filed challenging pharmaceutical patents.