AOP Orphan announces three-year results on Ropeginterferon alfa-2b in Polycythemia Vera at ASH

High rates of durable hematological response and symptom control with good tolerability were reconfirmed with Ropeginterferon alfa-2b after 36 months of treatment - Disease Modification by Ropeginterferon alfa-2b was illustrated by high molecular response rates, associated with the ability to reduce allelic burden of both mutant JAK2 and importantly also non-JAK2 mutations which are believed to have a role in disease progression - In line with molecular findings, disease or treatment related secondary malignancies including 2 cases of acute myeloid leukemia occurred only in patients receiving HU - AOP Orphan´s submission for marketing authorization of Ropeginterferon alfa-2b in the EU is in the final stage of EMA review.

AOP Orphan Pharmaceuticals AG (AOP Orphan) announces latest follow-up results on Ropeginterferon alfa-2b in patients with Polycythemia Vera (PV) from CONTINUATION-PV presented at ASH 2018.

CONTINUATION-PV is an open-label, multicenter, phase IIIb study assessing the long-term efficacy and safety of Ropeginterferon alfa-2b versus hydroxyurea (HU) or best available treatment (BAT) in patients with PV who previously participated in the PROUD-PV study.

Ropeginterferon alfa-2b is a novel, long-acting, mono-pegylated proline interferon (ATC L03AB15). It is administered once every 2 weeks initially, or monthly after stabilization of hematological parameters. It is expected to be the first interferon approved for PV worldwide. AOP Orphan´s submission for marketing authorization in the EU is in the final stage of EMA review.

Clinical evidence

Previously, at 12 months of treatment, Ropeginterferon alfa-2b was shown to be non-inferior to hydroxyurea (HU) in Complete Hematologic Response (CHR) and to have a significantly better safety and tolerability profile. . At 24 months Ropeginterferon alfa-2b achieved a significantly higher CHR of 70.5% versus 49.3% compared with HU/BAT (p=0.0101).

After 36 months of treatment Ropeginterferon alfa-2b sustained higher CHR response rates compared to HU/BAT (70.5% vs. 51.4%; p=0.0122). Further, the composite endpoint, CHR including disease symptom improvement was higher in patients treated with Ropeginterferon alfa-2b compared to HU/BAT (52.6% vs. 37.8%; p=0.0437).

Disease modification evidence

66.0% of PV patients treated with Ropeginterferon alfa-2b, but only 27.0% having received HU/BAT showed a mutant JAK2 molecular response (p<0.0001) after 36 months. Importantly, molecular response strongly correlated with CHR, emphasizing the clinical relevance of mutant JAK2 allele burden reduction.

Analysis of additional non-JAK2 mutations, which are believed to contribute to disease progression revealed that Ropeginterferon alfa-2b, but not HU was able to reduce their respective mutant allele burden. This suggests that only Ropeginterferon alfa-2b but not HU has the ability to suppress additional clones with different mutations and modify the disease at the molecular level.

In line with molecular findings, disease or treatment related secondary malignancies occurred only in patients receiving HU/BAT, including 2 cases of acute myeloid leukemia, 1 melanoma and 2 basaliomas, whereas 3 malignancies (glioblastoma, seminoma, adrenal neoplasm) most likely unrelated to treatment were reported for patients treated with Ropeginterferon alfa-2b.

A similar number of patients experienced adverse events (89.8% for Ropeginterferon alfa-2b, 90.6% for HU) and treatment-related adverse events (74.8% for Ropeginterferon alfa-2b, 78.7% for HU). The most common (>10%) treatment-related

adverse events anemia, thrombocytopenia and leukopenia occurred more frequently with HU, whereas liver enzyme increase was mainly observed with Ropeginterferon alfa-2b.

No new safety signals appeared in the third year of treatment.

Professor Heinz Gisslinger from the Medical University of Vienna, Austria presenting the results at ASH stated, "The observed superior efficacy of Ropeginterferon alfa-2b over hydroxyurea/best-available-therapy after 36 months, is a clear proof of the long-term value of this treatment modality. Thus, Ropeginterferon alfa-2b will provide a valuable and safe new first line therapy for PV patients".

Professor Jean-Jacques Kiladjian from the Saint-Louis Hospital & Paris Diderot University in France, concluded, "The disease modification capability of Ropeginterferon alfa-2b suggested by a significant reduction of not only mutant JAK2, but also non-JAK2 allele burden and the specific targeting of the malignant clone, holds promise for improvement of progression-free survival and long-term patient benefit."

About Ropeginterferon alfa-2b

Ropeginterferon alfa-2b is a novel, long-acting, mono-pegylated proline interferon (ATC L03AB15) with improved pharmacokinetic properties offering improved tolerability and convenience. It is administered once every 2 weeks, or monthly during long-term maintenance, and is expected to be the first interferon approved for PV worldwide. AOP Orphan´s submission for marketing authorization in the EU is currently under EMA review.

Ropeginterferon alfa-2b was discovered by PharmaEssentia, a long-term partner of AOP Orphan. Ropeginterferon alfa-2b has Orphan Drug designation in the European Union, Switzerland and the United States of America.

In 2009, AOP Orphan has in-licensed from PharmaEssentia Corporation the exclusive rights to develop and commercialize Ropeginterferon alfa-2b in PV, other MPNs and CML for European, Commonwealth of Independent States (CIS), and Middle Eastern markets.

About Polycythemia Vera

Polycythemia Vera (PV) is a cancer of the blood-building cells in the bone marrow resulting in a chronic increase of red blood cells, white blood cells and platelets. This condition may result in circulatory disorders such as thrombosis and embolism, as well as malignant transformation to myelofibrosis or leukemia. While the molecular mechanism underlying PV is still subject of intense research, current results point to a set of acquired mutations, the most important being a mutant form of JAK2 that make the malignant clone.

About AOP Orphan Pharmaceuticals AG

AOP Orphan is a multinational company with headquarters in Vienna, Austria focusing on clinical research, development and distribution of medicines for rare and complex diseases. The company also provides individualized and customized services to meet and accommodate the needs of physicians and patients across Europe, the Middle East & Asia. Currently AOP Orphan is concentrating on rare and complex diseases in HematoOncology, Cardiology & Pulmonology, and Neurology & Metabolic Disorders.