The European Patent Office’s decision on May 7 revoking one of Celgene Corp.’s (CELG) patents on Revlimid, a derivative of thalidomide, may lead to a broader challenge to related patents that could seriously curtail some $5 billion of Celgene’s $7.5 billion in annual revenue.

That’s the assessment of analysts at M-CAM, the intellectual property asset management advisory firm run by David Martin and David Pratt and based in Charlottesville, Virginia. M-CAM wouldn't identify the client who paid for the report.

Shares of Celgene fell 48 cents to $113.10 in afternoon trading. The company has said it would appeal the decision.

The revocation may mean generic drug companies will be able to produce their versions of the drug before Celgene’s current exclusivity runs out in 2024.

The appeal could take as long as 5 years.

Officials for Celgene and Hayman Capital couldn't be reached immediately for comment.

“A systematic and rigorous review of the available precedent information provides a sound basis for the invalidation of many other Revlimid® patents, including those currently listed in the FDA’s Orange Book, on the grounds that they are based on an older drug and that the use of the drug in the treatment of cancer was obvious,” the executive summary of the M-CAM analysis says.

If the invalidation of the entire Revlimid portfolio were systematically pursued by a third party, such as Kyle Bass’s Hayman Capital, it could “materially and adversely impact Celgene,” the M-CAM analysis asserts.

The core Revlimid compound patent “is and has always been based on an old drug (thalidomide) and the ‘innovations’ on which Revlimid is based, going back to its priority date in 1996, are obvious in light of precedent innovation and hence not entitled to patent protection in the United States or any of the nearly 70 countries where Revlimid® is approved,” the analysis says.

Because the base patent of the Revlimid families of patents is not valid, then all of the Revlimid patents are subject to validity or commercial relevance challenges.

To be sure, many of the Revlimid patents have to do with testing for contraindications and not just the compound.

Thalidomide has been on the market since 1957 and was originally used as a sedative until it was found to cause birth defects in women who took the drug.

In the 1960s, thalidomide was found to help in the treatment of disease by inducing, enhancing, or suppressing an immune response.

A 1970 scientific study found thalidomide derivatives to have the same immunomodulatory properties as thalidomide.

In 1991, another study established the clinical action of thalidomide in inhibiting tumor necrosis factor α (TNFα).

“In light of these precedents, examiners of Celgene’s ‘517 patent should have found it obvious that a closely‐related chemical analog like lenalidomide would reasonably
exhibit similar properties and therefore should not have issued this core Revlimid® patent upon which all of the Revlimid® patents are based.

The challenge of Revlimid before the EPO was brought by Teva Pharmaceuticals and Mylan N.V.

Revlimid is approved by the U.S. Food and Drug Administration for the treatment of cancer and other autoimmune diseases such as multiple myeloma,
mantle cell lymphoma, and myelodysplastic syndrome.

While M-CAM noted that some commentators have expressed opinions as to whether the revocation of the patent in the EPO proceeding will invite additional scrutiny of Celgene’s U.S. polymorph patents, those may not be the most at risk.

“We see much more comprehensive challenges to Revlimid® that strike at the entire suite of patents given exclusivity in the Orange Book.

“While the market has been primarily focused on the EPO opposition proceeding, Celgene’s case against Natco Pharma, and, most recently, Hayman Capital’s filing of inter partes review (IPR) petitions, the focus should be much more broadly applied.

M-CAM asserted that Hayman’s petitions “are well argued and aimed at the core” Revlimid compound patent and Revlimid patents on methods of drug distribution.

“The patents covering methods of avoiding fetal exposure to teratogenic drugs are the easiest to attack on grounds of obviousness,” M-CAM said.

The full report can be found at

To reach the reporter responsible for this story contact Dan Lonkevich at 707 318-7899 or