An FDA advisory committee has some serious concerns about the cardiovascular safety profile of J&J diabetes drug Invokana (canagliflozin).

In a hearing tomorrow, FDA’s Endocrinologic and Metabolic Drugs Advisory Committee will pore over a raft of safety signals—including bone fractures, urinary tract infections and the drug’s effectiveness in patients with renal impairment as well as CV factors—on the experimental type 2 diabetes drug, which is in the running to be the first SGLT2 inhibitor approved. The category includes Lilly/BI candidate empagliflozin, said to be on the verge of being filed with FDA, as well as AstraZeneca/BMS drug Forxiga (dapagliflozin), which won approval in Europe but was torpedoed by FDA early last year. The drugs reduce blood glucose by blocking the mechanism by which the body reabsorbs glucose so that it’s instead excreted through urine.

Reviewers’ concerns about dapagliflozin centered on cancer risks, noted CreditSuisse’s Catherine Arnold, and the absence of a cancer signal, plus confirmation of the drug’s efficacy in reducing HgbA1c, are encouraging for canagliflozin, though the briefing documents suggest that the committee is taking “a cautious stance” given “an imbalance in stroke events.”

“Lacking a satisfactory discussion/resolution of [stroke] risk, we expect the FDA to take a conservative stance and await more data from the cana CANVAS trial, particularly bearing in mind that CV issues were not a concern with dapagliflozin,” wrote Arnold in an analyst note. “Near-term approval of cana seems at risk, pending AdCom debate. Resubmission of dapa is expected soon, and will give another avenue of hope for a class approval.”

J&J’s Janssen presented results from a sub-study of their 4,330-patient Phase III CANVAS trial at the European Association for the Study of Diabetes meeting in October. Those data, which looked at 1,718 patients at elevated risk of cardiovascular disease, found reductions in A1C levels, body weight and blood pressure.  However, the clinical trial also found increased LDL levels in patients receiving the drug, which could account for a slightly elevated level of cardiovascular events. The company’s global Phase III canagliflozin clinical program has enrolled 10,285 patients in nine studies.

Boehringer Ingelheim and Lilly reported positive results from a Phase III empagliflozin trial earlier in the week. That trial will ultimately enroll over 14,500 patients, the companies said, and they expect to file the drug sometime this year in the US, Europe and Japan.