Evaluating Safety & Efficacy of Apremilast in the Treatment of Cutaneous Disease in Patients With Recalcitrant Dermatomyositis

1. Sponsor Name (PI): Carole Bitar, MD
2. Sub-PI: Erin Boh, MD, PhD; Brittany Stumpf, MD; Collaborator: Nakhle Saba, MD
3. # of Participants Sites: 1, Tulane University 4: Participant Countries: United States

II. PRODUCT INFORMATION

1. Study Title: A phase 2, open label single arm study for evaluating safety \& efficacy of apremilast in the treatment of cutaneous disease in patients with recalcitrant dermatomyositis.
2. Clinical Phase: Phase II clinical trial
3. Primary Celgene Product: Apremilast

III. CONCEPT DESIGN AND RATIONAL

1. Therapeutic Area: Immunology
2. Specialty: Connective tissue disease
3. Disease State: Dermatomyositis

4-If other specify: None

1. Study Rationale: Dermatomyositis is an inflammatory disease that predominantly involves the skin with or without proximal muscle weakness. First line treatment for dermatomyositis is systemic steroids however due to long-term side effects, patients are usually treated with a steroid sparing agent. There is no known consensus on treatment guidelines for dermatomyositis and many anti- inflammatory medications have been successfully used. Tulane University is a referral center for recalcitrant dermatomyositis cases.The investigators present the case of a 57 y.o female patient with multidrug recalcitrant dermatomyositis showing complete remission of her skin disease with apremilast and improvement of her muscle disease. This patient was diagnosed with dermatomyositis. Over a 6-year period, she was treated with adequate trials of multiple immunosuppressive agents, including hydroxychloroquine, mycophenolate mofetil, azathioprine, methotrexate, soriatane, Intravenous immunoglobulin (IVIG), tacrolimus, chlorambucil, infliximab and rituximab. For the last four years, physicians were unable to lower corticosteroids below 40 mg per day. Her disease continued to flare despite these therapies. Chronic steroid use resulted in insulin dependent diabetes mellitus as well as other steroids associated side effects. While on stable doses of mycophenolate mofetil, prednisone and rituximab, the patient developed arthritis and was started on apremilast 30 mg twice a day. Two months into her treatment she noticed significant improvement of her skin disease and then nearly complete clearance of the skin. Her muscle weakness lagged behind and she noticed improvement after 9 months of being on apremilast with normalization of her aldolase and CK. The patient was able to wean off all immunosuppressive agents and prednisone. She was in remission for over 2 years and off all medications. She experienced a mild flare of skin disease recently and she resumed apremilast only and cleared immediately and continues on apremilast as a monotherapy. Patient experienced mild nausea and diarrhea with apremilast that improved four weeks into the treatment. She was able to discontinue insulin, lose weight and she has continued to be clear of both skin and muscle symptoms for over 1.5 years.

This case was accepted as a poster presentation at the 2018 Annual Meeting of the American Academy of Dermatology "Poster #: 6672 - Apremilast: a Potential Treatment for Dermatomyositis." Following this successful outcome, the investigators initiated apremilast in 3 other patients with recalcitrant dermatomyositis. Two patients had recalcitrant cutaneous disease and responded to add on therapy of apremilast in 2 months with significant improvement of their skin disease. The third patient had refractory dermatomyositis to several steroid-sparing agents and with severe muscle disease was started on apremilast for arthritis. She experienced significant improvement of her muscle weakness together with decrease in her muscle enzyme creatine kinase.

These very exciting findings triggered the idea of studying apremilast as an adjunct treatment for recalcitrant cutaneous disease in dermatomyositis patients. This is a novel idea; apremilast was never studied for dermatomyositis. Apremilast may have more advantages in dermatomyositis compared to other immunosuppressive treatments. Dermatomyositis patients may have lung involvement, and apremilast is an agent that doesn't have lung side effects in contrast to methotrexate for example which is one of the main steroid sparing agents used for dermatomyositis.

The pathogenesis of dermatomyositis is multifactorial with environmental, genetic and immune factors contribution.T helper-1 (Th1) and T helper-2 (Th2) immune pathways play a fundamental role in dermatomyositis.There is increase in proinflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin (IL) 1, IL 6, and interferon (INF) α,γ shifting the immune balance to a Th1 response.Th1 immune response was also involved in the pathogenesis of interstitial pneumonia in the setting of dermatomyositis.IL4 released by lymphocytes infiltrating skin and muscles in dermatomyositis patients contributes to increase in Th2 response in conjunction with Th1 response.

Apremilast is a PD4-E inhibitor currently used for psoriasis and psoriatic arthritis.However, its usage on patients with dermatomyositis has not been investigated.

By inhibiting PDE-4 apremilast increases the level of cyclic adenosine monophosphate (c-AMP), leading to decreased expression of proinflammatory cytokines including TNF-α and INF-γ thus inhibiting Th1 response. Apremilast can also block Th2 response by interfering with the level of IL6 secreted by type2 macrophages.While the mechanism of action of apremilast in dermatomyositis is unknown, we suggest that apremilast can be a potential treatment option for dermatomyositis through interfering with Th1 and Th2 response.

Apremilast is a well-tolerated oral medicine with transient gastrointestinal side effects. Apremilast offers an additional treatment option for those patients with recalcitrant dermatomyositis, unresponsive to more conventional therapy.

1. Treatment and Dosing: Investigators will enroll patients seen at our facilities with a known diagnosis of dermatomyositis who are still experiencing cutaneous disease after a trial of systemic steroids and one steroid-sparing agent. Investigators will add apremilast to their treatment regimen according to the approved dosage for psoriasis and psoriatic arthritis: 10 mg orally one time on day 1, 10 mg orally twice daily on day 2, 10 mg orally in AM and 20 mg orally in PM on day 3, 20 mg orally twice daily on day 4, 20 mg orally in AM and 30 mg orally in PM on day 5, then 30 mg orally twice daily thereafter.
2. Brief Study Synopsis: With limited treatment options available for dermatomyositis, investigators hypothesize that apremilast, a phosphodiesterase-4 (PDE-4) inhibitor, is a safe and efficacious add-on treatment in patients with recalcitrant cutaneous dermatomyositis.

The study will investigate the efficacy, safety and toxicity of apremilast given at 30 mg twice daily to patients with recalcitrant cutaneous dermatomyositis. Clinical response will be assessed at 1 and 3 months. Patients will also be evaluated for durability of their response for up to 6 months.

Treatment will be monitored with frequent clinical visits (0, 1, 3 and 6 months) and blood tests (CBC, CMP, CK, aldolase). Treatment will be discontinued at disease progression or unacceptable adverse events. Disease progression is defined as a 4 points increase in CDASI score, worsening of muscle disease by MMT-8 score and 5 points increase in DLQI.

5 mm skin biopsies from lesional skin will be performed before treatment with apremilast and after 3 months of treatment for gene expression profiling and confirmatory immunohistochemical stains.

1. Sampling and correlative analysis

Although, the proposed mechanism of action of apremilast is though PDE-4 inhibition resulting in c-AMP upregulation, the exact biological process that leads to dermatological response in dermatomyositis remains ill-defined.Investigators propose to perform gene expression profiling (GEP) using RNA sequencing on skin biopsies collected before and after treatment with apremilast. In addition, we plan to confirm our GEP findings at the protein level using immunohistochemical (IHC) stains.

1. Tissue sampling and preparation
2. Tissue collection 5 mm punch biopsy from dermatomyositis skin lesions will be performed at baseline and another 5 mm punch biopsy will be performed at the 3-month time point. Each biopsy will be vertically split in two pieces and snap frozen on dry ice then it will be stored at -80C for further analysis with RNA sequencing and IHC stains.
3. RNA extraction At the end of all timeline collections, each skin biopsy will be mechanically broken down followed by mRNA extraction using the RNeasy extraction Kit from QIAGENzz. mRNA will then be stored at -80°C for subsequent RNA sequencing as detailed below.
4. Correlative Analysis

Determining the mechanism of action of apremilast in dermatomyositis.

1. Gene expression profiling RNA extracted form skin biopsies collected before and after in vivo treatment with apremilast (as detailed above) will be subjected to RNA sequencing. Illumina strand-specific TruSeq libraries will be prepared from the polyA selected RNA and subjected to 1x100 base sequencing on an Illumina HiSeq2500 machine. The number of samples proposed here (10 samples before treatment and 10 samples after treatment) is expected to yield sufficient statistical power for this approach; smaller numbers have been used in similar approaches to investigate drugs' mechanism of action (usually three samples). RNA-seq analysis will be performed in conjunction with the Tulane Cancer Crusaders Next Generation Sequence Analysis Core (Tulane Cancer Center - https://tulane.edu/som/cancer/research/core-facilities/cancer-crusaders/). Gene and isoform expression will be determined using RSEM and differential expression will be analyzed using EB-seq. Genes that are identified as differentially expressed between the two groups with a False Discovery Rate (FDR) of < 0.05 will be subjected to analysis by Ingenuity (IPA, Redwood City, CA). This analysis will group the identified genes into specific pathways, cell types, or disease process. A similar approach will be conducted using Gene Set Enrichment Analysis (GSEA). These experiments and GEP analysis will be performed in conjunction with our collaborator's (Dr. Nakhle Saba) lab, given his extensive experience in this field.
2. Protein analysis Information identified by Ingenuity or GSEA (signaling pathways, regulatory molecules, etc…) will be verified using IHC staining on select samples.