'Positive surprise' for Biogen in lupus, but all eyes on CTAD data this week

Biogen is joining AstraZeneca on a strong positive for its lupus candidates as the pair face going head-to-head on the market.

Biogen, which is also being closely watched for its Alzheimer’s phoenix from the flames drug data out this Thursday at the Clinical Trials on Alzheimer's Disease meeting, quietly announced positive phase 2 data in lupus this morning, a rare win in the field and for the biotech of late.

The phase 2 LILAC study was testing its drug, BIIB059, in a two-part study that pitted the drug versus placebo in patients with active cutaneous lupus erythematosus (CLE), including chronic and subacute subtypes, with or without systemic manifestations and in individuals with systemic lupus erythematosus (SLE) with active joint and skin manifestations.

Top-line data show the CLE part of the study met its primary endpoint (p<0.001) by demonstrating a dose response of BIIB059 on the percent change from baseline in the Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity (CLASI-A) score at week 16. (CLASI-A is an outcome measure that can detect a change in CLE skin disease activity.)

Study participants with CLE treated with 50 mg, 150 mg and 450 mg of BIIB059 experienced reductions in CLASI-A scores of 40.9% (p=0.008), 48% (p=0.001) and 42.5% (p=0.001), respectively, versus 14.5% with placebo.

The SLE part of the study also met its primary endpoint of reducing disease activity in individuals with SLE as measured by change from baseline in total active joint count at week 24 (treatment difference = -3.4 for BIIB059 450 mg versus placebo: p=0.037). Total active joint count is the total number of tender or swollen joints, with joint involvement being a common symptom in people with SLE.

RELATED: One year after flop, AstraZeneca's phase 3 lupus trial hits endpoint

“In addition, improvements in skin disease and overall disease activity were consistently observed across multiple secondary endpoints,” the biotech said in a statement. More detailed data will be revealed next year.

“There is substantial unmet medical need for people with lupus given the limited number of treatment options available to help manage this difficult-to-treat and chronic disease,” said Nathalie Franchimont, M.D., Ph.D., vice president of Biogen's lupus and multiple sclerosis portfolio.

“We are excited by the LILAC study results, and the potential for BIIB059 to be a meaningful new treatment option for patients living with lupus. We also believe these results support Biogen’s goal of continuing to build a multi-franchise portfolio by bringing potential new treatment options to people with great unmet medical need.”

Just last month, AstraZeneca said it was planning to file for approval of its hope, anifrolumab, specifically in SLE in the second half of next year using data generated across mid- and late-phase trials for the anti-IFNAR1 antibody.

But it’s been a rocky path: Anifrolumab looked to be on the ropes last year when AstraZeneca’s first phase 3 trial missed its primary endpoint. However, AstraZeneca made mid-study tweaks to its second phase 3, switching to a different primary endpoint, and delivered data that paint anifrolumab in a more favorable light. The data have made AstraZeneca bullish about its prospects.

Its drug differs in MOA from Biogen’s, as analysts at Evercore point out: It is “NOT [sic] a direct IFN blocker – directed against BDCA2.”

Its top analyst, Umer Raffat, admits it’s hard to do “apples to apples versus AstraZeneca just yet,” but notes that Biogen’s best efficacy was seen in cutaneous part of the lupus trial (on CLASI)—where the effect size is up to 34% (placebo adjusted).

“When I look at AstraZeneca’s results, they reported it instead on a responder basis: 49% of pts had a 50% reduction in CLASI score (vs 25% in placebo arm).”

While we can’t yet see how these two compare, Raffat notes that this is “encouraging for Biogen nonetheless.”

Analysts at Cantor said it was a “positive surprise,” as it did not see “any success in our base case model, so this opportunity would be upside for our valuation, and we would expect the stock to be up today,” (which it is, just, perhaps showing how much the market is laser-focused on Thursday's Alzheimer's update). It sees the drug as a $1.5 billion opportunity in the U.S., should it gain approval.

The FDA approved GlaxoSmithKline’s Benlysta in 2011. That approval marked the arrival of the first new lupus drug for 50 years and the first-ever biologic treatment for the disease. Since then, the drought has returned as companies including Ablynx, Biogen and Xencor have swung and missed at lupus.

And last year, UCB and Biogen’s other lupus drug dapirolizumab pegol also failed to clear a phase 2b study, missing its primary endpoint in dose responses compared to placebo.

The Lupus Foundation of America estimates that 1.5 million Americans and at least 5 million people worldwide have a form of lupus, which predominately hits women, usually at a childbearing age.