Al Sandrock
Analyst · Oppenheimer
Thank you, Michel. I'd like to start by saying a few words about aducanumab. The accelerated approval of aducanumab has generated discussions reflecting a broad range of opinions, including about its efficacy, the FDA selection of the accelerated approval path, and the regulatory process in general. Since June 7th, the FDA has made several clarifying statements on these topics. As always, we deferred to the FDA as the lead voice on such matters. They are the independent regulatory body charged with weighing the data expertly and dispassionately in order to make critical decisions that have the potential to impact millions of people. But I thought it would be helpful to add our perspective about several of these topics, including our interactions with the agency. We are proud of the work our dedicated team has done to develop aducanumab and the hope it brings to patients with Alzheimer's disease. We are equally proud of the professionalism both our team and the FDA demonstrated during a very lengthy process. We therefore welcome a formal review into the interactions between FDA and Biogen on the path to the approval of aducanumab. A better understanding of the facts is good for everyone involved to assure confidence in both the therapy and the process by which it was approved. We will cooperate fully with the review, even as we prioritize the issues that affect patients. I want to underscore that it is normal and appropriate for scientists and clinicians to discuss the data from experiments and clinical trials to debate and to disagree on the interpretation of the data. That is how science advances, and we welcome these discussions. However, I would like to correct some of the misinformation we have seen recently. First, several people have stated that all anti-amyloid antibodies clear amyloid from the brain. This is factually incorrect. First-generation anti-amyloid antibodies, such as bapineuzumab and solanezumab, are not specific for aggregated forms of A beta or target soluble and monomeric A beta, and crenezumab, being an IgG4, is deficient in effector function. As a result, these antibodies do not clear amyloid from the brain. This slide shows the amyloid PET imaging results from the peer reviewed literature of these first-generation antibodies. Crenezumab and solanezumab had no significant difference from placebo on amyloid plaque burden. Bapineuzumab did a show a significant difference from placebo in the Phase 3 trials. But this was largely driven by an unexplained increase in amyloid plaque burden in these placebo treated patients in the mild to moderate stage of Alzheimer's disease. We believe this increase in amyloid plaque in placebo patients must have been a superious result, as we now know that plaque buildup reaches a maximum by the time the patients have mild cognitive impairment. In short, there is no evidence that the first-generation antibodies against Abeta actually removed amyloid plaque. There is no basis for using the failure of these antibodies as a reason not to approve aducanumab. We have also seen statements that all of aducanumab's results are post hoc; that is also factually incorrect. The primary and secondary endpoints had been pre-specified in the Phase 3 trial protocols and statistical analysis plans before the first patient was enrolled into the trials. The aducanumab label shows the results on these pre-specified endpoints based on data that had already been collected at the sites by the time the trials were prematurely terminated on 03/21/2019. Separately, some have contended that ARIA led to unblinding. We took great care to ensure that the neurologists who assess the clinical outcome measures did not know about the occurrence of ARIA. One way in which we assured ourselves that unblinding did not affect the results was to examine the clinical outcomes after ARIA was seen. If ARIA had effective blinding, the results after ARIA might be expected to change. This slide shows that the results, excluding data that had been obtained after ARIA events, were the same as the overall results. Thus, we are confident that unblinding due to ARIA did not affect the results of the Phase 3 trial of aducanumab. And finally, some people have opined that the approval of aducanumab would inhibit the development of other drugs for Alzheimer's disease. This statement is contradicted by precedent. Prime example that the history of drug approvals for HIV-AIDS, non-Hodgkin's lymphoma, and multiple sclerosis to name just a few. In neurology, the first medicine ever approved for MS was in 1993 when when beta interferon received accelerated approval in the U.S.. Within the next several years, two other types of beta interferon were approved after controlled clinical trials showed that they slowed the progression of disability. Today, there are more than 20 drugs approved for the treatment of MS, all of which reduce the risk of relapse, or slow the progression of disability, or both. All new molecular entities were approved based on randomized controlled clinical trials that continued to be conducted to this day, nearly 30 years after the accelerated approval of beta-interferon. We believe a similar situation is just starting to unfold with Alzheimer's disease. Over the coming years, data will become available from Phase 3 trials of several second-generation antiamyloid antibodies which are capable of effectively removing amyloid plaque. And we also will have the results of the post-marketing trial of aducanumab. These data should address any residual uncertainty surrounding the efficacy of this class. In the meantime, the main serious risk associated with aducanumab is ARIA. Based on data from the Phase 3 trial, ARIA, which is an amyloid -related imaging abnormality, occurred in 41% of patients who took aducanumab, 10 mg/kg, and 10% of patients who took placebo. Of the patients taking aducanumab that experienced ARIA, 24% experienced clinical symptoms. In other words, about 10% of patients treated with the approved dose of aducanumab experienced symptomatic ARIA, serious symptoms were reported in 0.3% of patients. Alzheimer's disease is 100% fatal. And before death, it robbed people of themselves. Should these additional clinical studies confirm that this class of drugs is effective in slowing clinical decline, as Michel mentioned, patients who lack access to aducanumab may no longer be appropriate for treatment. We have been discussing the aducanumab data for many months now. Aducanumab was approved for use in the U.S. on June 7th, and the data are summarized clearly in the label. Our hope is for doctors to discuss the benefits and risks of taking aducanumab, with their patients and caregivers, based on rational analysis and accurate information. We are doing what we can to provide that information to the prescribing community in a number of ways. First, we will continue to present at scientific forums and publish analyses from our Phase 3 trials of aducanumab with a focus on publishing the primary manuscript and disseminating additional data to inform clinical practice, including the management of ARIA. This includes 4 presentations planned for the AAIC Conference next week. Second, we are moving with a sense of urgency to finalize the design of the aducanumab post-marketing confirmatory Phase 4 controlled study intended to verify the clinical benefit of aducanumab in Alzheimer's disease. We are still working through the details and are actively engaged with regulators. Our goal is to execute this study as expeditiously as possible and well ahead of the post-marketing commitment of approximately 9 years. Third, we have a unique data generation opportunity with EMBARK, with the embark long-term extension study. Just this month, we enrolled our last patient in the trial, bringing the total enrollment in the study up to roughly 1,700 Alzheimer's disease patients. The two-year EMBARK study will include patients previously treated with aducanumab for up to approximately 6.5 years, thereby generating important long-term safety and efficacy data for aducanumab. We've planned to present the EMBARK baseline data at an upcoming medical meeting, which should yield important insights on the effects of treatment interruption, the longer-term impact of reducing amyloid plaques, and the potential benefits of continued treatment. Lastly, we plan to initiate a real-world observational study in Alzheimer's disease called ICARE AD-US in order to collect real-world long-term effectiveness and safety data on aducanumab. We're also evaluating additional formulations of aducanumab with the goal of increasing patient confidence. Last month, we initiated a Phase 1 study to evaluate bioavailability of a subcutaneous formulation of aducanumab and continued to engage with regulators on the appropriate development strategy. Finally, we continue to advance our innovative pipeline of potential Alzheimer's disease treatments. This includes Lecanemab, our other anti-amyloid antibody that we are collaborating on with Eisai. Lecanemab was recently awarded breakthrough therapy designation by the FDA, and we are working with Eisai to engage with the FDA and pursue the optimum regulatory pathway. We also look forward to the readout of the Clarity Phase 3 study of Lecanemab expected next year. In addition to our anti-amyloid approaches, we are also targeting Tau, the primary component of Neurofibrillary tangles, another pathological hallmark of Alzheimer's disease. Although we were disappointed to learn that the Phase 2 study of gosuranemab in early Alzheimer's disease did not meet the primary or secondary endpoints, we do not believe these results diminish the relevance of Tau as a potential therapeutic target in Alzheimer's disease. Whereas we have discontinued the BIIB092 program, we are continuing the development of BIIB080, our antisense oligonucleotide, which aims to reduce the production of all forms of Tau, both intra and extracellular. Results of the Phase 1 trial will be presented at AAIC next week. In addition to Alzheimer's disease, this quarter we continue to progress a broad neuroscience pipeline with positive data readouts in depression and stroke, both areas in need of innovation. First, in neuropsychiatry in collaboration with Sage, we were excited to learn that the Phase 3 WATERFALL Study, evaluating a 50 milligram dose of zuranolone in major depressive disorder, achieved its primary endpoint. Despite the pronounced placebo effect observed in the WATERFALL study, 2 weeks of zuranolone treatment resulted in a statistically significant reduction in depressive symptoms at day 15, as measured by the HAM-D 17 scale, versus placebo. Zuranolone treatment also resulted in a rapid onset of action showing treatment effects at day 3, 8, and 12. The safety profile was similar to that seen previously in that most treatment-emergent adverse events were mild to moderate in severity, and we observed no signal of increased suicide idealization or behavior, or withdrawal symptoms. We continue to believe that zuranolone, with its rapid treatment response, durable treatment effects after a 2-week dosing period, and differentiated tolerability, has the potential to transform treatment for people suffering from depression. We are now working with Sage to determine the optimum filing path. The WATERFALL study is also -- is part of the robust development program for zuranolone, which also includes the ongoing SHORELINE, CORAL, and SKYLARK studies. We expect to report topline data from CORAL and SHORELINE in 2021. We are working with Sage to evaluate enrollment rates for the SKYLARK study, and we'll provide updates when that work is completed. We also obtained positive data from the Phase 2a study of TMS-007 in acute ischemic stroke. Current standard of care in the treatment of ischemic stroke calls for the use of thrombolytic agents within 3-4.5 hours of symptom onset. The approved agents also carry the risk of intracranial hemorrhage, or ICH, which increases with time. During the Phase 2a study of TMS-007, now referred to as BIIB131, the patients were dosed 4.5 to 12 hours after the onset of stroke symptoms with an average of 9.5 hours. There was no symptomatic ICH in the BIIB131 group. When compared to placebo, BIIB131 increased the rate of recanalization of occluded intracranial arteries, as visualized by MRI angiography in patients with large vessel strokes. Moreover, more patients regain the ability to function independently as measured by the Modified Rankin scale at day 90 compared to placebo. We are encouraged by the results of this study and are hopeful that BIIB131 could have the potential to be a next-generation thrombolytic drug that safely extends the treatment window after stroke onset. We plan to advance BIIB131 into the late stages of development as soon as possible. We also bolstered our MS pipeline through a proposed license and collaboration agreement with InnoCare for a Phase 2 oral small molecule BTK inhibitor for the potential treatment of MS. Orelabrutinib, a covalent BTK inhibitor with high selectivity and demonstrated CNS penetrant, is currently being studied in a global placebo-controlled Phase 2 study in relapsing remitting MS. The ability of orelabrutinib to cross the blood-brain barrier, combined with its high kinase selectivity, differentiates it from other BTK inhibitors currently in development for MS. Looking toward the remainder of the year, we also have two pivotal readouts remaining in ALS and depression. Earlier this month, we completed the 1-year placebo controlled treatment period of the Phase 3 study of Tofersen in SOD1 ALS, and we expect a readout by this fall. We also recently enrolled the first participant in ATLAS, a Phase 3 trial of tofersen initiated in clinically pre-symptomatic SOD1 mutation carriers. Our hope is that treating people earlier in this disease may provide the best opportunity to slow or even delay the onset of this terrible disease. In summary, this quarter, our R&D organization made significant progress advancing our pipeline. In addition to the accelerated approval of aducanumab, we completed 5 mid-to-late stage readouts in several key therapeutic areas characterized by high unmet need, including depression and stroke. The field of neuroscience is rapidly advancing. And with the investments we have made in prioritizing genetically validated targets, deploying biomarkers in early stage clinical programs, and building our human and technological capabilities, we believe we are well-positioned to take advantage of the many opportunities offered by this exciting area of science for the benefit of patients. I will now pass the call over to Mike.