Notes from AASLD: Apples and Oranges and Null Responders

The liver disease community – if not the investment community – has largely moved on from the novelty of comparing Vertex Pharmaceuticals' telaprevir and Merck's boceprevir, the two direct-acting antivirals that together form the threshold to a new era in hepatitis treatments if the buzz at the American Association for the Study of Liver Diseases is any indication.

Instead, physicians are celebrating the fact that two therapies may soon be available that can help patients achieve success rates that handily best the current 50% success rate from the standard of care interferon and ribavirin therapy, which is described as 48 weeks of constant flu-like symptoms and PMS.

The sense of promise is palpable at AASLD, now under way in Boston, where many of the sessions are standing room only.

A lot of the excitement now is around the IL28b genetic marker and its implication for better cure rates, and the lure of a still-years-away all-oral therapeutic regimen.

But first, there will be protease inhibitors. Merck and Vertex, who are jockeying to be first-to-market with a direct-acting antiviral for hepatitis C, plan to complete FDA submissions by the end of the year, with approval possible in mid-2011.

Based on overall profile, the odds-on favorite for best-in-class in this initial class of two seems to be telaprevir, but boceprevir may find a top-rung niche in experienced patients.

However, comparisons can be tough. Vertex had no short-course option in the Phase III study of telaprevir in experienced patients, REALIZE. Final results in that study have not yet been reported, but top line data showed 65% of experienced patients treated with telaprevir achieved SVR compared to 17% in the control arm.

Meanwhile, Merck released data at AASLD showing their response-guided therapy plan, which shortens the treatment period for patients who respond early, can work in prior treatment failures.

Another question frequently asked of presenters this year at AASLD concerns the definition of null responder, that is, patients who have had the poorest results with standard of care.

The definition of null responder used by Merck in RESPOND-2 is those who achieved less than 1 log decrease in viral load after the four-week lead-in period with standard of care. According to the abstract on the trial presented at AASLD, 33% of null responders (15/46) in the response-guided arm achieved SVR, a statistically significant improvement over the control arm, in which none of 12 patients had a cure. Null responders in the 44-week triple therapy arm had a 34% cure rate (15/44), also statistically significant.

That null-responder definition, however, appears to be at odds with the FDA guidance. In the document, FDA describes that population as people with "less than a 2 log10 reduction in HCV RNA at week 12" of standard of care therapy, the point at which the therapy is typically dropped for futility.

A footnote in the draft indicates that "other definitions for null response have been proposed, such as less than 1 log decline in HCV RNA at week four of treatment. However, failure to achieve a greater than 2 log decline … at week 12 has typically been used as a treatment futility criterion," and use of the 1 log decline definition "causes a gap in classification for individuals with a viral load reduction" that falls between the two.

Vertex has used that definition in its REALIZE study in experienced patients. In an interview, Robert Kauffman, chief medical officer at Vertex, reasoned that using what he called the "standard definition" prospectively to identify patients at the time of enrollment, rather than "on treatment," ensured that all patients were in the appropriate group.

To test the difference in the two definitions, Vertex used a four-week induction arm in REALIZE, and looked at the correlations between less than a 1 log drop at week four of the delayed start and the standard definition, Kauffman explained.

The outcome of the analysis was "a clear difference," he said. The two groups had different responses to the triple therapy. In addition, he said, the trial showed that both groups can have a "very, very good response."

A subanalysis of REALIZE reported at AASLD showed that among combined partial responder and relapser patients in the lead-in arm, 18% (31/171) fit the less than 1 log reduction definition at the end of the lead-in with standard of care. Of those patients 58% (18/31) went on to achieve SVR compared to 31% (46/147) patients prospectively-defined as prior null responders using the "standard" definition.

– Shirley Haley

flickr image by e g g used under a creative commons license.

VEGF & Colorectal Cancer: How Do You Know When to Stop?

Fifty million Elvis fans can't be wrong. What about nine Phase III trials?

Avastin is a $5.7 billion drug, with activity in at least five tumor types with every indication of gaining more (it's pending for approval in gastric cancer based on data presented at the 2009 ASCO annual meeting [it is not (Herceptin is!); IVB regrets the error] and positive data in ovarian cancer was presented at the plenary of the 2010 meeting). Some projections have it becoming the top selling drug in the world in 2014 with annual sales of $9 billion. (For more on Avastin's performance in ovarian cancer, check out "The Pink Sheet.")

But it all started out with colorectal cancer.

With success like that, and the VEGF mechanism of action seemingly proven in the setting, of course other drug development projects followed. "There is clearly room to improve on anti-angiogenic therapy in CRC," Scott Kopetz from MD Anderson Cancer Center said at this year's ASCO meeting, and agents with oral bioavailability and lower production costs could have real market advantages.

But, as Kopetz reminded us during an ASCO session on novel possibilities for treating colorectal cancer, small molecule angiogenesis inhibitor options – including the multi-targeted receptor tyrosine kinase inhibitors – haven't worked. Fourteen small molecule VEGF receptor antagonists have been tested (and failed) in CRC – among them early disappointments like AstraZenenca/Schering's PTK787 and more recent failures with Pfizer's sunitinib, GlaxoSmithKline's pazopanib, Bristol-Myers Squibb's brivanib, and AstraZeneca's vandetanib and cediranib just weeks ago. (see Pharmaceutical Approvals Monthly). That includes a total of nine Phase III trials and over 10,000 patients studied, by Kopetz's calculations.

And - "despite over 10,000 patients enrolled," he said, "unfortunately there's no evidence yet that anti-angiogenic agents, besides bevacizumab, confer benefit."

With such a host of attempts and no positive results, maybe it's time to move beyond VEGF in colorectal cancer. After all, there's scads of other pathways to pursue – from MEK to PI3 kinase to Src to Notch to Hedgehog, as Wells Messersmith from the University of Colorado mapped out.

Maybe it isn't quite time to call it quits on angiogenesis, though. Kopetz held out a little hope – and from the back of a McCormick Place hangar it was hard to see how much of a veil of Avastin glory was in his eyes – there's still the large molecule angiogenesis projects out there.

The Phase III on VEGF-Trap, sanofi-aventis/Regeneron's aflibercept, should report out in December. So perhaps we should all keep our hopes up a little longer.

When Innovation Isn't Enough

There is always a self-congratulatory flavor to bio’s annual meeting. Which is as it should be: it’s the lobbying group’s best venue for justifying its membership dues.

And I think they have – with exhibit 1 being their clever R&D tax credit, a $1 billion piece of reform money to provide a few hundred biotechs with non-dilutive cash most can’t get anywhere else.

And yet I still can’t shake the feeling that, by and large, BIO’s leaders – or maybe bio’s members – are fighting the last war, over innovation, when the new fight is all about value.

Even a political idiot like me can get why Jim Greenwood reads gushing letters from patients about drugs that have saved their lives. And given just how few important biotech medicines have gotten approved lately, I understand why Dendreon’s Provenge gets a prominent mention. And I also get why Greenwood didn’t mention its cost ($93K for a full course of therapy). He would then have had to explain just how Dendreon calculated that Provenge will be cheaper than Taxotere per-month-of-life-saved (on theoretical average, Provenge gives you an extra three). Which would have been kind of boring.

But why wasn’t the Provenge price front and center in the more purely business speeches about cancer products (or frankly any biological therapy)? Given just how often people gave passing nods to the needs of payers (e.g., in Steve Burrill’s theories-of-everything talk), you’d figure that the Provenge price might be a relevant topic. Pricing is at least passingly important to a product’s commercial prospects and so apparently exceptional pricing might indeed be worth a chat, whether you think that price bodes well or ill for the industry (e.g., the Provenge price will be a) the straw that breaks the camel’s back or b) another gold nugget that shows just how strong the camel’s back still is or c) a meaningless topic because Dendreon, supply constrained, is only going to sell a few thousand therapies so total costs for any one payer won’t rise to a meaningful level). But I heard nothing about it.

Or let me put this another way. Greenwood said that "the recent recession and policy hurdles” hadn’t “diminished our passion to innovate.” First, I don’t think most investors or, frankly, executives would agree. For most VCs I know, passion for pharmaceutical innovation has turned into a massive case of indigestion (to continue the gastro-intestinal metaphor: VC portfolios are clotted with innovative companies).

But more importantly have Greenwood’s “recession and policy hurdles” increased our willingness to prove value – which isn’t the same thing as novelty and which Greewood’s r&ph will certainly require?

I don’t get the sense that drug companies have done much to show that they see the difference. (Full disclosure here: I’m now so interested in this subject that I’m part of a group exploring a new company focused on it.)

Innovation, by and large, can be judged pretty objectively. A new mechanism is innovative. A new compound too. But value is subjective – what’s valuable to you may be burdensome to me. Yet the industry’s main arbiter of value, clinical trials, too often proves value to only one audience: regulators.

That audience is certainly crucial. But everything we’ve learned over the last year says that a regulatory audience is hardly predictive of what other equally crucial audiences want: Lilly’s Effient, Bristol/AZ’s Onglyza and J&J’s Simponi and Ultram ER all provide customers with – well, given their commercial performance, very little they’re willing to pay the price for.

This isn’t to say that these drugs’ suppliers couldn’t create the necessary value. It’s to say that they haven’t, at least in part because they’re focused on just one audience.

Instead of simply proving that a pain drug reduces pain without causing other big problems, maybe the trial should prove that the pain drug does something the payer wants from it – maybe a reduction in follow-up visits to the doctor to get another pain drug. Or delays the prescription of an opioid. Or allows a generic to be used in most cases. Or shows that a GP, after a relatively low-cost visit, can prescribe the product without sending the patient along for specialist follow-up. Or can avoid an expensive diagnostic procedure. A me-too cancer drug (and there are plenty of them in development) could justify premium pricing by measuring, along with whatever purely clinical data it needs for approval, reductions in hospital-acquired infections, or length-of-stay.

I spoke with one CEO who told us that the nurses in hospitals testing his oncology drug loved it because they spent less time cleaning up after patients nauseated by the standard of care. I asked: Are you measuring how much less time they’re spending? No, he said.

Biotech wants to be paid like it’s always been paid: for promises of novelty. I’d be curious to hear a biotech claim that it should be paid, as the UK’s NICE pays for Millennium/J&J’s Velcade, when the drug delivers the value the payer and patients want. That value could be a particular medical outcome, or better quality of life, or lower medical costs. Or something that makes the payer’s services more attractive to the employers its competing with other payers to win as clients. But it isn’t necessarily whether it’s clinically better than placebo. Or even standard of care. Effient’s head-to-head trial against Plavix proved – in crude summary – that it’s clinically better. But payers clearly don’t see enough value to justify switching away from a drug soon to be generic.

So my suggestion: if bio really wants to promote the long-term health of the biotech industry (and the broader pharma business as well), maybe the theme for the next convention should focus on customers.

How about “What’s In It for Me?”

image from flickr user zizzy used under a creative commons license