The Concept of Biosimilars: From Characterization to Evolution-A Narrative Review

Biologic agents are currently the fastest emerging segment of drug expenditure. Unlike chemically synthesized small-molecule drugs, biologics are more complex, medicinal products produced by a living organism. They have become part of the standard of care in the treatment of a large variety of diseases, such as growth disorders, autoimmune diseases, cancer, cardiovascular illnesses, hemophilia, and rare genetic conditions, to name a few. Biosimilars, which are copies of biologics that are highly similar, were introduced in the market with an aim to offer efficacy that is not clinically different from the originator or reference product, at lower prices. We aim to clarify the concept of biosimilar, from definitions, history, market entry, challenges faced, and future evolution. For that purpose, we performed a literature search on the sites of the medicines regulatory agencies and PubMed from 1990 to 2014 with the keywords "biosimilars," "market," and "regulatory." In 2006, the first biosimilar, somatropin [rDNA origin], was marketed and led the way for biosimilar drug manufacturing. As a result, manufacturers have entered a diversified competition, facing challenges in manufacturing these complex agents, such as immunogenicity and efficiency. Biosimilars are set to evolve differently in various markets, namely the U.S., Japan, the European Union, and the "pharmerging" economies.

IMPLICATIONS FOR PRACTICE

This article highlights the importance of biosimilars, as a cost-cutting strategy, in the delivery of state-of-the-art health care in developing countries, at a fraction of what a reference biological agent would cost.

Factors associated with risk of central nervous system relapse in patients with non-core binding factor acute myeloid leukemia

Central nervous system (CNS) relapse is uncommon in patients with acute myeloid leukemia (AML) with the use of high-dose cytarabine containing chemotherapy regimens. The clinical and molecular features associated with a higher risk of CNS relapse are not well defined. We assessed the incidence and outcome of CNS relapses among 1245 patients with relapsed/refractory AML referred to our institution between 2000 and 2014. CNS leukemia relapse was observed in 51 patients (4.1%). Using a multivariate regression model and after adjusting for age, FLT3-ITD mutation (OR = 2.33; P = .02) and elevated LDH (>1000 IU/L, OR = 1.99; P = .04) were independent predictive factors for CNS relapse. Patients under 64 years of age with 0, 1, or 2 baseline adverse features had a probability of 3.8%, 7.0%-8.0%, and 13.9% for developing CNS disease, respectively. Our study identifies patients with AML at higher risk for CNS relapse in whom prophylactic CNS therapy may be warranted.

The evolving landscape of oncolytic virotherapy (OV) clinical trials (CT): Meta-analysis

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Background: The number of new OV CT have been increasing along with the evolution of cancer immunotherapy. The OVs induce direct oncolysis and enhances the host innate and adaptive immunity. There are ongoing efforts to improve the anticancer efficacy of OVs with combinational strategies. However, there has been no direct comparison of OV CTs to evaluate their different dose levels, administration routes, frequencies, and the types of OVs and combinations. Methods: A random-effect meta-analysis was performed to evaluate pooled best ORR of all the existing OV phase II and III trials from publications and presented abstracts from ASCO, AACR, and ASGCT from 1/1/2016 to 12/4/2016. MeSH term “oncolytic” was used in PubMed. The inclusion criteria were: phase II or III, solid tumor, reported ORR. We evaluated the best ORR among different viruses, DNA vs. RNA, intratumoral (IT) vs. intravenous (IV) / intra-arterial (IA), and single vs. combination. Results: From 79 publications and 176 presented abstracts identified, 6 published studies and 12 presented abstracts were selected and pooled (n=875). The best ORRs were: DNA OV 23% (15 ~ 34%) vs. RNA OV 31% (13 ~ 58%), IT 36% (23 ~ 51%) vs. IV/IA 16% (10 ~ 25%), and single agent 22% (16 ~ 31%) vs. combinations 35% (17 ~ 58%). The combination OV CTs were either with chemotherapy (n= 144), chemoradiation (n= 23), or immunotherapy (n= 69). Each OV’s ORR is summarized in the table below. Direct comparison of the secondary endpoints: clinical outcome and adverse events will be presented with the poster. In general, the OV CTs had good overall safety profile and most adverse events were less than grade 3. Conclusions: The antitumor effect of OVs against solid tumors is evident and consistent in many trials. The largest data currently available is with herpes virus and coxsackie virus appears to have the best ORR possibly due to the combination with immunotherapy. The above results confirm the promising clinical activity of novel oncolytic viral vectors both alone and in combination. [Table: see text]

Impact of achievement of complete cytogenetic response on outcome in patients with myelodysplastic syndromes treated with hypomethylating agents

Two hundred and sixteen consecutive patients with MDS and abnormal karyotype treated with hypomethylating agents between 4/04 and 10/12 were reviewed. Median follow-up was 17 months. Using IWG criteria, best responses were complete response (CR) in 79 patients (37%), partial response (PR) in 4 (2%), and hematologic improvement (HI) in 10 (5%). Cytogenetic response (CyR) was achieved in 78 patients (36%): complete (CCyR) in 62 (29%) and partial in 16 (7%). CyR was achieved in 48 of 79 patients (61%) with CR, 1 of 14 (7%) with PR/HI, and in 29 of the 123 (24%) with no morphologic response. Median overall survival (OS) and leukemia-free survival (LFS) for patients with and without CCyR were 21 and 13 months (P = .007), and 16 and 9 months (P = .001), respectively. By multivariate analysis, the achievement of CCyR was predictive for better OS (HR = 2.1; P < .001). In conclusion, CyR occurs at a rate of 36% (complete in 29%) in patients with MDS treated with HMA and is not always associated with morphological response. The achievement of CCyR is associated with survival improvement and constitutes a major predictive factor for outcome particularly in patients without morphologic response. Therefore, the achievement of CCyR should be considered a milestone in the management of patients with MDS.

Hypertension induced by chemotherapeutic and immunosuppresive agents: a new challenge

BACKGROUND

Hypertension is a common adverse effect of certain anti neoplastic therapy. The incidence and severity of hypertension are dependent mainly on the type and the dose of the drug.

METHODS

We reviewed the literature for studies that reported the effect of anti neoplastic agents on blood pressure in patients with malignancies. The medical databases of PubMed, MEDLINE and EMBASE were searched for articles published in English between 1955 and June 2012. The effects of specific agents on blood pressure were analyzed.

RESULTS AND CONCLUSIONS

Hypertension is a prevalent adverse effect of many of the new chemotherapy agents such as VEGF inhibitors. Approximately 30% of patients treated for cancer will have concomitant hypertension, and crucial chemotherapy can sometimes be stopped due to new onset or worsening severe hypertension. The importance of a timely diagnosis and optimal management of HTN in this group of patients is related to the facts that HTN is a well established risk factor for chemotherapy-induced cardiotoxicity and if left untreated, can alter cancer management and result in dose reductions or termination of anti-cancer treatments as well as life-threatening end organ damage.