How A Kidney Drug Almost Torpedoed Concert Pharma’s IPO

price on the top of its $12 to $14 per share range on Feb. 13, and sell a million more shares than it originally planned. Concert raised about $75 million in its debut, and pocketed another $8.5 million when its underwriters used their right to buy more stock. (Shares closed on Friday at $8.90 apiece.) Crisis averted, as Concert now has enough cash to get it through the next few years, Tung says.

“You’ve got to raise money when you can raise money and we’ve lived through this as a management team, over the past couple of decades, we recognized that this is about taking advantage when you can take advantage,” Tung says.

So what about today’s CTP-499 data makes Concert think it has another opportunity it can take advantage of? Concert is hanging its hat on three main findings.

First there’s the impact on serum creatinine levels. The 65 patients who got CTP-499 for 48 weeks saw their serum creatinine levels increase by an average of 0.13 milligrams per deciliter, compared to a 0.21 mg/dl increase for the 58 patients who got a placebo. That’s a 38 percent difference, though the result was not statistically significant.

What was significant—in a statistical sense and, likely, a strategic one—was the finding that six of the patients on placebo saw their serum creatinine levels spike more than 50 percent over 48 weeks, compared to just one patient on CTP-499.

In addition to the creatinine findings, the study produced some data that hint that CTP-499 doesn’t work the way the company thought it did. Since pentoxifylline has anti-inflammatory properties, Concert expected CTP-499 would as well. (Inflammation is thought to play a role in diabetic kidney disease.) Instead, the Phase 2 data suggest that the drug tamps down fibrosis, a tissue scarring process that, left unchecked, progressively impairs kidney function.

Indeed, Concert saw a statistically significant difference between the two patient groups in two biomarkers of fibrosis—urinary fibronectin (52 percent less in the CTP-499 group) and plasma collagen IV (18 percent less)—after 48 weeks of treatment.

Tung says that these results provided a potential explanation for why patients didn’t see any significant positive effects after 24 weeks of treatment with CTP-499: since fibrosis is a more gradual process than inflammation, detecting the benefits of a treatment that affected it would take longer.

So do all those numbers add up to a molecule with the potential to gain approval from the FDA? Tung says the agency has been very vocal about “lowering the bar” for approval of drugs that can slow potential kidney failure. Recently, for example, the agency came to a written agreement with Research Triangle Park, NC-based NephroGenex (NASDAQ: [[ticker:NGX]]) on a study design that includes the 50 percent serum creatinine increase measure as one of the primary endpoints. Historically, the bar has been set at 100 percent, so this is a good sign for Concert—both because it has already shown CTP-499 can significantly reduce the number of patients reaching the 50 percent milestone, and because using the 100 percent standard would almost certainly require a longer trial.

Concert might also be able to speed its next trial of CTP-499 by focusing on patients with more damage to their kidneys at the outset. Sicker patients’ kidney function tends to deteriorate more quickly—meaning Concert could get a faster and clearer signal of whether the drug is working.

Those are “mights” and “ifs,” of course, and it will be a while before Concert has new clinical data on CTP-499; the company hasn’t yet sat down with the FDA to discuss a Phase 3 study of the drug. But even if CTP-499 never makes it to market, Concert has at least shown it can take a punch.

“I’ve been in this field for over a quarter of a century. You’re going to get luck—some of it’s going to be good, some of it’s going to be bad,” Tung says. “What we strive to do is give ourselves the opportunity to weather the bad times by having multiple shots on goal, a team with the type of grit and determination to stick through the bad times, and to force success to happen.”

Author: Ben Fidler

Ben is former Xconomy Deputy Editor, Biotechnology. He is a seasoned business journalist that comes to Xconomy after a nine-year stint at The Deal, where he covered corporate transactions in industries ranging from biotech to auto parts and gaming. Most recently, Ben was The Deal’s senior healthcare writer, focusing on acquisitions, venture financings, IPOs, partnerships and industry trends in the pharmaceutical, biotech, diagnostics and med tech spaces. Ben wrote features on creative biotech financing models, analyses of middle market and large cap buyouts, spin-offs and restructurings, and enterprise pieces on legal issues such as pay-for-delay agreements and the Affordable Care Act. Before switching to the healthcare beat, Ben was The Deal's senior bankruptcy reporter, covering the restructurings of the Texas Rangers, Phoenix Coyotes, GM, Delphi, Trump Entertainment Resorts and Blockbuster, among others. Ben has a bachelor’s degree in English from Binghamton University.