Cytokinetics may be counting down the days until the FDA decides whether to approve its cardiovascular drug aficamten. But, for a biotech planning to commercialize its first drug—and without Big Pharma backing—the company's CEO Robert Blum is keeping his cool.
“We believe that the data that supports approval are unequivocal, very solid [and] consistent across all endpoints,” Blum told Fierce in an interview.
“We've done well by our interactions with regulatory authorities,” added the CEO, who pointed out that South San Francisco-based Cytokinetics is also in discussions with regulators in Europe. Meanwhile, there is also progress in China, where Sanofi owns the rights to the drug.
The approval application for aficamten, a cardiac myosin inhibitor, was based on a phase 3 trial in patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM), which is characterized by a thickening of the wall between the left and right ventricles that can block blood flow.
The FDA is set to make a call on whether to approve aficamten for oHCM by Dec. 26. In fact, analysts had been banking on an outcome by the original decision date in September, before the agency made the surprise move to push this back three months after asking for a Risk Evaluation and Mitigation Strategy plan from the biotech.
The phase 3 study results backing up the approval application showed that aficamten improved patients' exercise capacity, as measured by increasing peak oxygen uptake compared to placebo. Since the biotech initiated the rolling approval submission, a separate late-stage study in patients with less severe cases of oHCM showed that the drug improved oxygen capacity by 1.1 milliliters per kilogram per minute in patients with genetic heart enlargement, easily besting the 1.2-point loss in those given a standard-of-care beta blocker.
There is already a drug on the market for oHCM in the form of Bristol Myers Squibb’s Camzyos, also known as mavacamten, another cardiac myosin inhibitor. But Blum declined Fierce’s suggestion that Cytokinetics is going into direct competition with Camzyos, which just brought in $296 million for BMS in third-quarter sales.
Instead, he pointed out that Cytokinetics’ relationship with Camzyos stretches way back. Early work on the BMS drug was covered by a research collaboration between Cytokinetics and MyoKardia, which BMS went on to buy for $13.1 billion in 2020.
“Mavacamten is a very good drug,” Blum told Fierce in an interview on the sidelines of the Jefferies Global Healthcare Conference in London on Monday.
“It's currently being used, we would argue, in maybe 15% to 20% of eligible patients,” he added. “So we don't see that it is in our interest to compete directly with BMS, but rather open up the aperture on a market that could benefit from broader category penetration.”
Cytokinetics’ ambitions for aficamten aren’t limited to oHCM. The biotech is currently running a phase 3 study in non-obstructive hypertrophic cardiomyopathy (nHCM), a condition where heart muscle is thickened, but not enough to block blood flow.
Camzyos failed its own late-stage study for nHCM, but the data were close enough to a win to hearten Cytokinetics’ leadership.
“One of the endpoints was confounded by an unusually large placebo effect,” Fady Malik, M.D., Ph.D., Cytokinetics’ head of R&D, said about BMS’ detailed readout. “But if you look at the underlying mechanistic data—biomarkers fell quite substantially, cardiac function markers of cardiac relaxation improved.”
“So there was evidence of clinical improvement that was not quite statistically significant, but nearly so,” Malik told Fierce.
If the Cytokinetics’ nHCM readout in the second quarter of 2026 demonstrates that aficamten can succeed where Camzyos failed, it could double the potential market for aficamten from an estimated 120,000 patients that Cytokinetics is currently sizing up for oHCM alone.
Unusually, Cytokinetics is planning to take aficamten to market in the U.S. and Europe by itself, without the commercial firepower of a Big Pharma in support. While the biotech was at one point courted by Novartis, Blum said it “has always been our intention to build our own commercial organization.”
“That's always been Plan A,” the CEO said.
The man tasked with pulling off this plan is Andrew Callos, Cytokinetics’ chief commercial officer. He explained to Fierce that HCM is a “really concentrated market” where “a biotech can do really well.”
“We can go to market with, like, 125-150 sales reps and we can afford the marketing spend,” Callos said.
“So we can have comparable [market] access and then the differentiation really shines through—differentiation on profile from a clinical point of view, from a REMS point of view, from a patient services point of view—and that's where we think we can expand the market,” he added.
Cytokinetics’ pipeline also includes two other clinical-stage drugs being trialed for symptomatic heart failure. One of these, called omecamtiv mecarbil, is a cardiac myosin activator. That candidate is in a confirmatory phase 3 study for patients with symptomatic heart failure with severely reduced ejection fraction, which Malik described as the company’s “nearest-term, next potential approval.”
There’s also ulacamten, which—like aficamten—is a cardiac myosin inhibitor. Cytokinetics is testing ulacamten in a phase 2 study in patients with symptomatic heart failure with preserved ejection fraction with left ventricular ejection fraction of over 60%.
According to Blum, these candidates are further proof that Cytokinetics has always been preparing to make the leap to a commercial company without the safety net of a Big Pharma’s backing.
“We've built a pipeline purposely so that when we do show up for physicians and patients, it's not just for a single product [or] a single indication, but a portfolio of multiple medicines,” the CEO said.
So does that mean Cytokinetics would rule out any offer from a Big Pharma, no matter how tempting?
“That's not to say that we don't understand we have fiduciary obligations if somebody were to make an offer that's in the interest of maximizing shareholder value,” Blum said. “We demonstrated that a couple of years ago when we were in those conversations, and we will again if the opportunity presents.”
“But in the meantime, Plan A is to build a commercial business—and to do that very well,” the CEO said.