AnaptysBio lost over $700 million in market cap Friday after reporting that IL-33 inhibitor etokimab, which it had hoped would compete with blockbuster inflammatory disease drug Dupixent, missed the primary endpoint in a trial to treat atopic dermatitis. The failure leaves the company with a slimmer in-house clinical pipeline that includes one ongoing study of etokimab and one candidate to treat autoimmune blistering disorders.
AnaptysBio Inc. (NASDAQ:ANAB) said top-line data from the Phase IIb ATLAS trial showed that all dosing arms of etokimab failed to meet the primary endpoint of improvement as measured by the Eczema Area and Severity Index compared with placebo at week 16.
The news drove down AnaptysBio's shares by $25.98 (72%) to $10.18 Friday.
The company's only other wholly-owned clinical assets are ANB019, an IL-36R inhibitor in Phase II testing for palmoplantar pustulosis and generalized pustular psoriasis, and ANB030, a PD-1 agonist that is slated to enter the clinic for inflammatory diseases next year.
The remainder of AnaptysBio's pipeline is being developed through deals.
The Tesaro Inc. unit of GlaxoSmithKline plc (LSE:GSK; NYSE:GSK) has exclusive rights to four cancer candidates from AnaptysBio under a 2014 deal. AnaptysBio is also partnered with Celgene Corp. (NASDAQ:CELG) to develop antibodies for inflammatory diseases; the most advanced is PD-1 agonist CC-90006, which is in a Phase I trial to treat psoriasis.
AnaptysBio had cash and investments of $444.4 million as of Sept. 30, which it expects to last at least into 2021.
While AnaptysBio will not halt the separate Phase II ECLIPSE trial evaluating etokimab in chronic rhinosinusitis with nasal polyps, it will postpone the start of a Phase IIb trial in eosinophilic asthma until the full ATLAS data set is analyzed. Interim data for ECLIPSE are expected next quarter.
AnaptysBio shares had already taken a hit in June following a readout from another anti-IL-33 mAb, REGN3500 from Regeneron Pharmaceuticals Inc. (NASDAQ:REGN) and Sanofi (Euronext:SAN; NASDAQ:SNY). Although that compound met the primary endpoint in a placebo-controlled Phase II study to treat asthma, it failed to show a greater benefit than the partners' Dupixent dupilumab (see "AnaptysBio Sags as Sanofi-Regeneron Trial Stokes IL-33 Doubts").
Regeneron gained $15.40 to $341.79 on Friday.
Another company with a potential Dupixent competitor, Dermira Inc. (NASDAQ:DERM), climbed $1.26 (18%) to $8.23 on Friday. Last month, detailed data from a Phase IIb trial showed its lebrikizumab reduced dermatitis disease severity at a dosing schedule that could be more convenient than that of Dupixent. Lebrikizumab prevents IL-13RA1/IL-4R heterodimer formation and downstream signaling (see "Dermira Data Could Bolster Bid as Dupixent Alternative").
Dupixent, a mAb that targets the alpha subunit of IL-4R and the IL-13 receptor, is approved to treat atopic dermatitis, asthma and chronic rhinosinusitis with nasal polyps. Dupixent has generated $1.6 billion in worldwide sales so far this year.
Targets: IL-13 - Interleukin-13; IL-13RA1 (IL-13Ra; CD213A1) - Interleukin-13 receptor α 1; IL-4R (IL-4RA; CD124) - Interleukin-4 receptor; IL-33 (NF-HEV) - Interleukin-33; IL-36R (ILRL2) - Interleukin-1 receptor-like 2; PD-1 (PDCD1; CD279) - Programmed cell death 1