With at least five patient deaths linked to its flagship anemia injection drug Omontys (peginesatide), Affymax is reeling from fallout which includes the near-collapse of its stock and the threat of at least one lawsuit.
Shares of Affymax all but collapsed yesterday, wiping out $525 million in market value as they plummeted 85% in value from $14.10 to $2.34 before crawling back to a closing price of $2.42 on NASDAQ.
The plunge followed the February 23 announcement by Affymax and its development and commercialization partner Takeda Pharmaceutical to voluntarily recall all lots of Omontys, a once-monthly intravenous treatment for anemia due to chronic kidney disease in adult patients on dialysis.
The recall followed reports of severe hypersensitivity reactions including anaphylaxis in 0.2% or about 50 patients—including fatal reactions in 0.02%—of the 25,000 patients within 30 minutes of their first IV dose in the post-marketing phase. In about one-third of these reports, reactions were serious enough to require “prompt medical intervention and in some cases hospitalization,” the companies said.
In an apparent sign of trouble earlier this month, Fresenius Medical Care said it saw "infrequent" allergic reactions in patients after their first dose of Omontys in a pilot program. The dialysis provider responded February 14 by holding off on a planned expansion of the pilot, but didn’t end the program altogether, saying it was still analyzing safety and efficacy data following injection of more than 56,000 doses in some 18,000 patients. On Sunday, Fresenius said it would end use of Omontys even though the drug was “generally well tolerated” in most of those 18,000 patients.
Worse, the Los Angeles law firm Glancy Binkow & Goldberg said yesterday it was investigating Affymax for possible violations of federal securities laws that may result in a lawsuit against the troubled drug developer: “The investigation focuses on allegations that certain statements issued by Affymax were false and misleading regarding the company’s business and financial prospects,” the firm stated.
The law firm said it is focusing on the statement made by Affymax and Takeda in announcing the Omontys recall. The companies attributed the recall to “new post-marketing reports regarding serious hypersensitivity reactions, including anaphylaxis, which can be life-threatening or fatal.” However, in a statement issued the following day, FDA said it received 19 reports of anaphylaxis from U.S. dialysis centers.
FDA’s statement alerted health care providers and patients of the Omontys injection recall, and urged health care professionals and consumers to report any adverse reactions to the agency’s MedWatch program: “Until further notice, health care providers should stop using Omontys and return the product to Takeda Pharmaceuticals.”
FDA approved Omontys, an erythropoiesis-stimulating agent (ESA) that aids in the formation of red blood cells, in March 2012, following two pivotal trials involving a total 1,608 patients.
“The most common side effects observed in 10 percent or more of dialysis patients treated with Omontys were diarrhea, vomiting, high blood pressure (hypertension), and joint, back, leg, or arm pain (arthralgia),” FDA said in its press release announcing approval of the Affymax drug. However, the agency approved Omontys with a Risk Evaluation and Mitigation Strategy (REMS) designed to enhance patient safety by requiring additional education for healthcare professionals as well as an assessment of drug use data.
Despite these precautions, FDA stated, results of the pivotal trials “showed Omontys was as safe and effective as epoetin in maintaining hemoglobin levels within the studies’ pre-specified range of 10 to 12 grams per deciliter."
In developing Omontys, Affymax and Takeda sought to offer an anemia alternative to epoetin, a three-times-weekly drug sold under the brand name Epogen (epoetin alfa) by its developer Amgen, as well as by Amgen licensee Johnson & Johnson under the brand name Procrit (epoetin alfa). However, Omontys racked up only $34.6 million in sales for Takeda last year, disappointing analysts who expected much better results from the drug. Piper Jaffray analyst Ian Somaiya last year told Bloomberg he predicted sales of Omontys would reach $700 million by 2017.