Court Rules That Momenta's Abatacept Appeal Is Moot

This week, the United States Court of Appeals for the Federal Circuit found that Momenta lacked standing to appeal a decision upholding a patent covering abatacept (Orencia) and said that Momenta’s appeal was rendered moot by the drug makers’ choice to stop developing its biosimilar.

Momenta had, in July 2015, used inter partes review to challenge all 15 claims of Bristol-Myers Squibb (BMS)’s US Patent 8,476,239, which covers stable formulations comprising the cytotoxic T-lymphocyte—associated protein 4 immunoglobulin molecule used to treat immune-mediated diseases. The US Patent Trial and Appeal Board upheld the patentability of all claims of the patent, and Momenta later appealed in the federal circuit.

BMS moved to dismiss the appeal, citing the constitutional requirements of Article III and noting that Momenta’s proposed biosimilar had failed in a phase 1 clinical trial and was subsequently withdrawn. In the phase 1 study, the proposed biosimilar did not meet its primary pharmacokinetic end points when compared with the US- and EU-sourced reference product.

Momenta, for its part, said that it had not halted development of the biosimilar on the heels of the missed end points and argued that the patent in question was hindering its development activities.

Then, in October 2018, Momenta announced that after a strategic review, it was halting development of a number of biosimilars, abatacept included. Momenta’s announcement indicated that the developer would focus on novel therapeutics and would only advance 2 of its late-stage biosimilars: an adalimumab candidate and an aflibercept candidate.

According to BMS, news of the program’s discontinuation demonstrated Momenta’s lack of standing. However, according to Momenta, if its partner Mylan later further developed the abatacept molecule, Momenta could have a potential right to royalties from the product. BMS argued that Mylan’s possible future development of the product “is too speculative” to provide standing, however.

The court ruled that Momenta does not, in fact, have standing and that Momenta’s appeal was mooted by its discontinuation of any development activity that could potentially infringe on the patent.