On 12 November, efficacy and safety data for AstraZeneca’s anifrolumab in moderate to severe systemic lupus erythematosus (SLE) from the pivotal Phase III TULIP-2 trial were presented at the American College of Rheumatology (ACR) Conference in Atlanta, US.

Although anifrolumab met its primary endpoint in the TULIP-2 trial, it failed to meet a different primary endpoint in the Phase III TULIP-1 trial, which was presented a day earlier. AstraZeneca is planning to file for approval of anifrolumab in the second half of 2020; in light of the new data presented, GlobalData believes that anifrolumab has a high likelihood of approval and will enter the market in the first quarter of 2021. 

The TULIP-2 trial assessed the difference between anifrolumab 300mg and placebo in a percentage of patients achieving the BILAG-based composite lupus assessment (BICLA). BICLA response at Week 52 was demonstrated in 47.8% and 31.5% of patients taking anifrolumab 300mg and placebo, respectively, with a Week 52 difference of 16.3% between the two treatment arms. Although there were no new safety signals, herpes zoster was more common in those receiving anifrolumab than placebo. Although anifrolumab met the primary endpoint for TULIP-2, it failed to meet the TULIP-1 primary endpoint, which was the SLE Responder Index – 4 (SRI-4), which is a more stringent assessment that requires full improvement of lupus symptoms in some organs; BICLA requires partial improvement in all organs. SRI-4 responses at Week 52 were 36.2% and 40.4% in anifrolumab 300mg and placebo arms, respectively; however, there were more serious adverse events that occurred in patients treated with placebo. Although anifrolumab failed its primary endpoint in TULIP-1, there was a reduction in annualized flare rate and more patients sustained oral corticosteroid reduction when compared to placebo. Furthermore, anifrolumab demonstrated significant clinical benefits when compared to placebo in SRI-5, SRI-6, SRI-7, and SRI-8. 

According to key opinion leaders (KOLs) interviewed by GlobalData, anifrolumab will directly compete with GSK’s Benlysta (belimumab); however, it is imperative to note that Benlysta gained approval from its two Phase III pivotal trials BLISS-52 and BLISS-76, which both contained primary endpoints of SRI-4 at Week 52. In BLISS-52, SRI-4 responses of 57.6% and 43.6% were observed in 10mg/kg IV Benlysta and placebo, respectively, while in BLISS-76, SRI-4 responses of 43.2% vs. 33.5% in 10mg/kg IV Benlysta and placebo were observed, respectively. Furthermore, Janssen’s Stelara (ustekinumab) and Eli Lilly’s Olumiant (baricitinib) will also be using SRI-4 as a primary endpoint. If Stelara—a direct competitor to anifrolumab and Benlysta—achieves this endpoint, it could be bad news for AstraZeneca and place the drug further down the pecking order if approved by the FDA. 

KOLs interviewed by GlobalData had mixed opinions about anifrolumab. Although anifrolumab did not meet its primary endpoint in TULIP-1, some KOLs believe this will not be a major issue for AstraZeneca as the SRI-4 also has its flaws. On the other hand, some KOLs believe that its onset of action is moderate and if it is approved, it will not be a significantly better drug than Benlysta because it failed to achieve the SRI-4 endpoint. Although anifrolumab failed SRI-4 it demonstrated clinical benefits in SRI-5, SRI-6, SRI-7, and SRI-8. Furthermore, BICLA is still a key endpoint for lupus patients as it is more discriminatory than the SRI measures in selecting patients with greater change in disease activity. AstraZeneca will most likely file using the data from TULIP-2 and due to the high unmet need present in this indication such as challenges in clinical design, lack of approved and efficacious therapies, and the heterogeneous nature of the disease, GlobalData believes that there is a high likelihood of approval for anifrolumab. 

Related Reports

GlobalData (2019) Systemic Lupus Erythematosus and Lupus Nephritis: Global Drug Forecast and Market Analysis to 2028, to be published