Drug developers have not had much luck establishing new candidates in the kidney dialysis space recently, but this has not kept them from trying. The latest entrant is Rockwell Medical Technologies, which hopes that its intravenous iron supplement will provide a safer alternative.
The Wisconsin group reported positive results from the second of two pivotal trials of soluble ferric pyrophosphate (Triferic) last week; shares ended the week up 50% at $8.27, valuing it at $330m. Clean safety appears to give the project a good shot at approval, but as hypersensitivity has dogged products like Omontys and Feraheme, regulators will give Rockwell’s trials a thorough going over. On its side, however, are data suggesting that Rockwell’s IV iron can reduce patient use of erythropoietin-stimulating agents (ESAs) at dialysis centres, which should be attractive for partners looking to lock up ex-US rights.
Data from Rockwell’s Cruise-2 trial found that use of soluble ferric pyrophosphate (SFP) – delivered via dialysate – arrested the decline of haemoglobin in kidney failure patients undergoing dialysis three to four times a week. On average, patients taking SFP experienced a decline of 0.5g/l, a statistical improvement on the 4.0g/l decline of patients on placebo; this confirms the findings of Cruise-1, announced in July, in which the numbers were similar with 0.6g/l increase for the SFP group and a 3.0g/l decline for placebo.
Anaemia in dialysis patients is caused by both a lack of native erythropoietin because of the kidney disease and blood loss from their treatment. ESAs are less effective in the absence of sufficient iron, and oral iron supplements have not been shown to be as effective as iron delivered intravenously; however, toxic iron buildup and anaphylactic reactions are risks of IV iron, so a better product is wanted.
Thus Rockwell was happy to tout the trials’ revelation that no cases of anaphylaxis or hypersensitivity were reported in 48 weeks of treatment in Cruise 2, and neither were there any cardiac events or cases of tissue iron overload. An imbalance in deaths was noted – seven in the SFP arm and two with placebo – but none was declared to be treatment related; Cruise-1 had an imbalance favouring placebo, of five vs three.
This finding likely will be closely examined by regulators and specialists when full data are released at the American Society of Nephrology meeting in November. Company executives say they will submit an FDA application in four to six months.
Rockwell will be attempting to break into a space occupied by such players as Galenica and Daiichi Sankyo, with Ferinject (Injectafer in the US) and Venofer respectively. Both products carry warnings about hypersensitivity reactions, so if Rockwell wins approval without such warnings it should have an edge.
The last attempt to break into the space was by Amag Pharmaceuticals' Feraheme, but this faield as its list price was higher than the reimbursement received by dialysis centres (Event – Amag needs to find fresh blood for Feraheme, February 6, 2012). Assuming that SFP approval comes sometime in late 2014, Rockwell will need to price it right or face a similar fate.
On the other hand, as a dialysis supply specialist Rockwell ought to benefit commercially from its already established relationships – it signed a supply agreement with DaVita in 2011 – and certainly it should have a good idea from discussions with customers as to the price the market will bear.
And it has already done some key pre-marketing work – a phase II trial called Prime found that patients receiving SFP had a 37.1% lower dose of ESAs. This could offer a clear pharmacoeconomic case for use of SFP that Feraheme had struggled to show, especially in the bundled payment environment in which dialysis centres now operate (Medicare dialysis rules to re-shape ESA market, July 28, 2010).
Nevertheless, regulators have tightened their safety requirements, so SFP is approaching some high-risk dates in 2014. However, an iron supplement that earns a benign safety label will have a clear unique selling point; should Rockwell achieve that, it will be down to establishing a winning economic case.