Insmed Dives 53% as Rat Data Prompt Arikace Clinical Hold
It doesn't say in the article if when the two year data was released. did the geniuses at Insmed have this data before the merger was completed.
By Trista Morrison
BioWorld Todsay Staff Writer
Shares of Insmed Inc. dropped 52.5 percent Tuesday after data from a two-year rat carcinogenicity study prompted the FDA to slap a clinical hold on a pair of nascent Phase III trials with lung infection drug Arikace (liposomal amikacin for inhalation).
Until then, Insmed had been having a pretty good year.
When the Monmouth Junction, N.J.-based biotech revealed plans to merge with privately held Transave Inc. last December, investors were uninspired, pushing the stock down about 7 percent. But the deal gave Insmed control of the merged company and a new lead product – Arikace – to replace Iplex (mecasermin rinfabate), which had failed a Phase II trial for muscular dystrophy the year before. (See BioWorld Today, June 26, 2009, and Dec. 3, 2010.)
Investors seemed to warm to the merger this year, amid the presentation of positive Phase II data for Arikace, progress moving into Phase III trials and a 1-for-10 reverse stock split that avoided Nasdaq delisting.
While shares often fall after a reverse split, Insmed's gained 137 percent over the last 4.5 months, closing at $11.35 on Monday.
By Tuesday, the shares (NASDAQ:INSM) had fallen $5.96 to close at $5.39.
Investors were clearly spooked by the clinical hold, which was based on the FDA's initial review of interim data from a long-term carcinogenicity study, in which rats received daily doses of Arikace by inhalation for up to two years.
The agency requested additional information on Arikace and data from the rat study, which Insmed anticipates being able to supply within 30 days.
Until the FDA is satisfied, however, recruitment and enrollment of patients into a Phase III trial for Pseudomonas lung infections associated with cystic fibrosis and a separate Phase III trial for nontuberculous mycobacterial lung disease are on hold. No patients have been dosed.
Insmed was unable to comment further on the hold due to an earnings-related quiet period, but the company plans to provide additional information in its second-quarter conference call, on Aug. 8.
Even if the clinical hold takes a bit longer to resolve than anticipated, Insmed should have enough cash to keep itself afloat. The company reported $104.9 million in cash, equivalents, short-term investments and CDs as of March 31 and had previously projected that the two Phase III trials would cost about $75 million.
The danger, of course, is that Insmed might not be able to get the program back on track. Rat carcinogenicity data have felled many a drug development program in the past; such data led to last year's complete response letter for Arena Pharmaceuticals Inc.'s obesity drug lorcaserin. (See BioWorld Today, Oct. 26, 2010.)
But while lorcaserin is a completely novel compound, Arikace is a reformulation of a well-known drug: the FDA-approved antibiotic amikacin. In its injectable form, amikacin is used to treat Gram-negative infections such as Pseudomonas. It carries a warning about ototoxicity and nephrotoxicity, but its label says nothing about carcinogenicity.
It could be that the carcinogenicity issue is related to Insmed's liposomal formulation, which is intended to provide a longer-acting effect. Insmed executives had previously predicted Arikace could be the first inhaled antibiotic to be administered once daily.
Or perhaps the inhaler itself could be to blame. Before Pfizer Inc. pulled its inhaled insulin product Exubera off the market, the company revealed that six of 4,740 patients treated with the drug had developed lung cancer, although the big pharma concluded that there were too few cases to determine whether the cancer was related to Exubera.
Arikace uses an eFlow Nebulizer System from PARI Pharma GmbH, of Gräfelfing, Germany.
Or maybe the carcinogenicity data will turn out to be a red herring. Cancer signals in animals don't always translate to human risks. Only time – and more data – will tell.
Assuming Arikace continues on its development path, the product would eventually compete against existing inhaled antibitoics such as TOBI (tobramycin solution for inhalation, Novartis AG) and Cayston (inhaled aztreonam lysine, Gilead Sciences Inc.).
Additionally, Mpex Pharmaceuticals Inc., which was acquired earlier this year by Axcan Holdings Inc., is in Phase III with Aeroquin (aerosol levofloxacin) for pulmonary infections in cystic fibrosis patients, and Aradigm Corp. recently reported good Phase IIb data with ARD-3100 (inhaled ciprofloxacin) in noncystic fibrosis bronchiectasis.
Nektar Therapeutics Inc. and Bayer AG are partnered on a Phase II inhaled amikacin product for pneumonia as well.
Published: August 3, 2011
