Anticuerpos conjugados a fármaco: la nueva generación de terapias biotecnológicas contra el cáncer / Antibody-drug conjugates: the new generation of biotechnological therapies against cancer

Resumen Los anticuerpos terapéuticos son proteínas recombinantes empleadas en el tratamiento del cáncer. Existe una nueva generación de anticuerpos monoclonales con actividad contra las células cancerosas, conocidos como anticuerpos conjugados a fármacos. Estas moléculas están integradas por tres elementos: un anticuerpo monoclonal, un fármaco citotóxico con alta potencia y un enlazador químico que los une. El anticuerpo reconoce antígenos tumorales, por lo que permite la entrega dirigida del agente citotóxico hacia las células cancerosas. Tras el reconocimiento de su antígeno, el anticuerpo conjugado a fármaco es endocitado por las células blanco, donde se induce la degradación lisosomal de la fracción proteica y se libera el fármaco citotóxico. En el presente artículo se revisan las características generales de los anticuerpos conjugados a fármacos y se describe la evidencia clínica de la eficacia y seguridad de los primeros cuatro aprobados por las agencias reguladoras de Estados Unidos y Europa.

Abstract Therapeutic antibodies are recombinant proteins used in the treatment of cancer. There is a new generation of monoclonal antibodies with activity against cancer cells, known as antibody-drug conjugates. These molecules are made up of three elements: a monoclonal antibody, a highly potent cytotoxic drug, and a chemical linker that binds them together. The antibody recognizes tumor antigens, thereby allowing targeted delivery of the cytotoxic agent to cancer cells. After recognizing its antigen, the antibody-drug conjugate is endocytosed by the target cells, where the protein fraction is degradated into lysosomes, releasing the cytotoxic drug. This article reviews antibody-drug conjugates general characteristics and describes the clinical evidence of efficacy and safety of the first four approved by regulatory agencies in the United States and Europe.

Marine drugs for cancer: surfacing biotechnological innovations from the oceans

This review will discuss the contributions of marine natural molecules, a source only recently found to have pharmaceutical prospects, to the development of anticancer drugs. Of the seven clinically utilized compounds with a marine origin, four are used for the treatment of cancer. The development of these drugs has afforded valuable knowledge and crucial insights to meet the most common challenges in this endeavor, such as toxicity and supply. In this context, the development of these compounds will be discussed herein to illustrate, with successful examples provided by cytarabine, trabectedin, eribulin and brentuximab vedotin, the steps involved in this process as well as the scientific advances and technological innovation potential associated with developing a new drug from marine resources.

Development of radioimmunoconjugate for diagnosis and management of head-and-neck subclinical cancer and colorectal carcinoma

ABSTRACT Scientific innovations in diagnostic methods are important drivers of cancer control and prevention. Noninvasive imaging of the epidermal growth factor receptor (EGFR) in head-and-neck squamous, cell carcinoma and colorectal cancer could be valuable to select patients for EGFR-targeted therapy, as well as to monitor the efficacy and occurrence of resistance to immunotherapy. In order to develop the first Brazilian radioimmunoconjugate for diagnosis, Cetuximab has been conjugated to p-SCN-Bn-DTPA chelator and radiolabeled with Indium-111. The conjugation methodology was optimized using different mAb:DTPA molar ratios, time was then reduced for immunoconjugate preparation, besides the protein recovery' percentage increased after purification (m = 83.8 ± 0.91 %). The stability of Cetuximab-DTPA at - 20 oC was evaluated for six months, and its integrity was greater than 90% (m =93.9 ± 1.5%, N = 24). The radioimmunoconjugate with specific activity of 185 MBq/mg showed radiochemical purity above 95% (m=96.8 ± 1.31 %, N = 15). We conclude that the radioimmunoconjugate 111In-DTPA-cetuximab is stable and may be applied to the diagnosis of EGFR-positive tumors.

Production of a conjugate between the rK346 antigen from Leishmania infantum and the horseradish peroxidase C for the detection of rK346 antibodies / Producción de un conjugado entre el antígeno rK346 de Leishmania infantum y la peroxidasa C de rábano picante para la detección de anticuerpos rK346

It was designed and characterized a reporter system to be captured by antibodies bound to ELISA plates. The system was designed with the rK346 from Leishmania infantum, a highly antigenic and specific protein. The rK346 was coupled to the horseradish peroxidase C (HRPc) from Armoracia rusticana using glutaraldehyde or sulfo-SMCC. Glutaraldehyde conjugation was performed in two steps. Separation of conjugates was carried out using a Sepharose S-200 in size exclusion chromatography (SEC); fractions were analyzed via HRPc activity and through ELISA plates sensitized with polyclonal anti-rK346 IgG purified from rabbit serum. A heterogeneous population of conjugates rK346-HRPc was obtained with molecular weights ranging between 109.7 ± 16.5 to 67.6 ± 10.1 kDa; with rK346-HRPc stoichiometries of 1:2; 2:1; 3:1; and 2:2. Conjugation using sulfo-SMCC was carried out first by introducing -SH groups onto the HRPc using the SATA reagent and the antigen was modified with sulfo-SMCC during 45 min. Separation and analysis of conjugates was performed similarly as with glutaraldehyde, resulting in a heterogeneous population of conjugates rK346-HRPc with molecular weights between 150.5 ± 22.6 to 80.0 ± 12.0 kDa; with rK346-HRPC stoichiometries of 2:1; 1:2; 2:2; and 1:3, with an increased conjugation efficiency in comparison with glutaraldehyde. This enables sulfo-SMCC to be used as a potential reagent for coupling the antigen to the HRPc, to design an economic, specific and easy method to apply as a reporter system, available to assess individuals at risk and/or at early and late stages of visceral leishmaniasis.

Se diseñó y caracterizó un sistema reportero para ser capturado por anticuerpos enlazados a placas de ELISA. El sistema fue diseñado con una proteína altamente antigénica y específica, la rK346 de Leishmania infantum. La rK346 fue acoplada a la peroxidasa C de rábano picante (HRPc) de Armoracia rusticana usando glutaraldehido o sulfo-SMCC. La conjugación con glutaraldehido fue realizada en dos pasos. La separación de los conjugados fue llevada a cabo a través de una cromatografía de exclusión molecular sefarosa S-200 (CES), las fracciones fueron analizadas midiendo la actividad HRPc y por placas ELISA sensibilizadas con inmunoglobulina G policlonal anti-rK346, purificada desde suero de conejo. Se obtuvo una población heterogénea de conjugados rK346-HRPc en un rango de pesos moleculares entre 109,7 ± 16,5 a 67,6 ± 10,1 kDa; con estequiometria rK346-HRPc de 1:2; 2:1; 3:1; y 2:2. La conjugación usando sulfo-SMCC se llevó a cabo primero introduciendo grupos -SH en la HRPc usando el reactivo SATA; el antígeno se modificó con sulfo-SMCC. La separación y el análisis de los conjugados se realizaron de forma similar que con el glutaraldehido, resultando en una población heterogénea de conjugados rK346-HRPc con un rango de pesos moleculares entre 150,5 ± 22,6 a 80,0 ± 12,0 kDa; con estequiometria rK346-HRPC de 2:1; 1:2; 2:2 y 1:3, y con una eficiencia de conjugación incrementada en comparación con glutaraldehido. De esta forma, se habilitó al sulfo-SMCC como un reactivo potencial para acoplar antígenos a la HRPc, como método para el diseño de un sistema reportero económico, especifico y fácil de aplicar, útil en la evaluación de individuos en riesgo y/o en estados tempranos o avanzados de leishmaniasis visceral.

Seasonal variation of haemoglobin A1c in a Portuguese adult population

Objective Haemoglobin A1c (Hb A1c) is routinely used for monitoring glycemic control in patients with diabetes. Hb A1c seasonal fluctuations can be directly related to different biological, geographical and cultural influences. Our purpose was to evaluate seasonal variation of Hb A1c in a hospital-based adult population over a period of 5 years.Materials and methods We analyzed retrospectively monthly Hb A1c mean values (DCCT, %) based on all the assays performed to adult patients at a tertiary care university Portuguese hospital between 2008-2012.Results We obtained 62,384 Hb A1c valid measurements, with a peak level found in January-February (7.1%), a trough in August-October (6.8%) and an average peak-to-trough amplitude value of 0.3%. This trend was observed in both genders and age subgroups evaluated.Conclusions There is a Hb A1c circannual seasonal pattern with peak levels occurring in winter months in this Portuguese population. This finding should be recognized in daily clinical practice to warrant better clinical and epidemiological interpretation of Hb A1c values. Arch Endocrinol Metab. 2015;59(3):231-5.

Reações infusionais imediatas a agentes imunobiológicos endovenosos no tratamento de doenças autoimunes: experiência de 2.126 procedimentos em um centro de infusão não oncológico / Immediate infusional reactions to intravenous immunobiological agents for the treatment of autoimmune diseases: experience of 2126 procedures in a non-oncologic infusion centre

Introdução: Com o crescimento do uso de drogas imunobiológicas (IBD) ampliamos o conhecimento sobre sua eficácia e segurança. Objetivo: Analisar as reações infusionais imediatas (RII) às IBD endovenosas - infliximabe (IFX), rituximabe (RTX), abatacepte (ABT) e tocilizumabe (TCZ) - no tratamento de doenças autoimunes. Método: Avaliamos 2.126 infusões feitas no CID (Centro de Infusão) em 268 pacientes. A droga usada, a indicação clínica, o tempo de infusão e o uso de pré-medicação foram determinados pelo médico prescritor. Foram consideradas RII todas as intercorrências apresentadas durante a infusão e/ou período observacional de 30 minutos. A conduta adotada nas RII seguiu os protocolos do CID. Resultados: Em relação ao tipo de IBD, as infusões foram distribuídas em: IFX (1.584; 74,5%), TCZ (226; 10,63%), RTX (185; 8,7%) e ABT (131; 6,16%). As RII foram descritas em 87 procedimentos (4,09%): 77 no grupo IFX e 10 no grupo RTX. Não foram descritas RII nos grupos de ABT e TCZ. A maioria foi considerada leve (n = 5; 41,17%) ou moderada (n = 50; 58,81%) e não houve reações graves. Das infusões interrompidas, 79 (92,9%) foram reiniciadas e concluídas com êxito. Apenas seis (0,28%) não foram concluídas por causa das RII. Conclusão: Apesar da diferença entre o número de procedimentos por droga, trata-se de uma análise de "vida real", na qual a incidência de RII foi semelhante à descrita na literatura. A baixa incidência de RII corrobora os dados de segurança tanto de forma quantitativa como qualitativa e ressalta a importância do acompanhamento médico especializado durante a infusão. .

Introduction: With the increasing use of immunobiological drugs (IBD), the knowledge about their effectiveness and safety has increased. Objective: To analyze the immediate infusional reactions (IIR) to intravenous IBD: infliximab (IFX), rituximab (RTX), abatacept (ABT) and tocilizumab (TCZ) on the treatment of autoimmune diseases. Method: 2126 infusions performed in the Infusion Centre - CID in 268 patients were analyzed. The used drug, its clinical indication, infusion time, and use of premedication were determined by the prescribing physician. All intercurrences presented during infusion and/or during a thirty minutes observation period were considered as IIR. The approach adopted in IIR followed the protocols of the Infusion Centre - CID. Results: Regarding the type of IBD, the infused drugs given were: IFX (1584, 74.5%), TCZ (226, 10.63%), RTX (185, 8.7%) and ABT (131, 6,16%). IIR were described in 87 procedures (9.4%): 77 - IFX group and 10 - RTX group. IIR were not described in ABT and TCZ groups. Most were considered as mild (n = 5; 41.17%) or moderate (n = 50, 58.81%) reactions; there were no serious reactions. Regarding to discontinue infusions, 79 (92.9%) were resumed and completed successfully. Only six (0.28% of infusions) were not completed because of IIR. Conclusion: Despite the differences between the number of procedures per drug, ours is a "real life" analysis, where the incidence of IIR was similar to that described in the literature. The low incidence of IIR corroborates the safety data, both quantitatively and qualitatively, and underscores the importance of specialized medical support during infusion. .

A conjugate of an anti-midkine single-chain variable fragment to doxorubicin inhibits tumor growth

Doxorubicin (DOX) was conjugated to a single-chain variable fragment (scFv) against human midkine (MK), and the conjugate (scFv-DOX) was used to target the chemotherapeutic agent to a mouse solid tumor model in which the tumor cells expressed high levels of human MK. The His-tagged recombinant scFv was expressed in bacteria, purified by metal affinity chromatography, and then conjugated to DOX using oxidative dextran (Dex) as a linker. The molecular formula of this immunoconjugate was scFv(Dex)1.3(DOX)20. In vitro apoptosis assays showed that the scFv-DOX conjugate was more cytotoxic against MK-transfected human adenocarcinoma cells (BGC823-MK) than untransfected cells (55.3 ± 2.4 vs 22.4 ± 3.8 percent) for three independent experiments. Nude mice bearing BGC823-MK solid tumors received scFv-DOX or equivalent doses of scFv + DOX for 2 weeks and tumor growth was more effectively inhibited by the scFv-DOX conjugate than by scFv + DOX (51.83 percent inhibition vs 40.81 percent). Histological analysis of the tumor tissues revealed that the highest levels of DOX accumulated in tumors from mice treated with scFv-DOX and this resulted in more extensive tumor cell death than in animals treated with the equivalent dose of scFv + DOX. These results show that the scFv-DOX conjugate effectively inhibited tumor growth in vivo and suggest that antigen-specific scFv may be competent drug-carriers.

Uso do abatacepte em uma paciente com artrite psoriásica / Use of the abatacept in a patient with psoriatic arthritis

Artrite psoriásica (AP) é uma artrite inflamatória soronegativa de causa desconhecida. Classicamente, a AP apresenta cinco formas clínicas, sendo a oligoartrite assimétrica a mais comum. Descrevemos o caso de uma paciente com AP refratária às drogas modificadoras da doença, que evoluiu com hepatite medicamentosa após quimioprofilaxia com isoniazida, administrada previamente ao tratamento com anti-TNFα. Em virtude do risco de ativação de tuberculose (TB) latente pela administração de anti-TNFα, da hepatotoxicidade decorrente do tratamento da TB, e baseado no fato de o tratamento da AP se assemelhar ao da artrite reumatoide, optou-se pelo tratamento empírico com abatacepte. Aproximadamente vinte dias após a segunda dose do biológico, a paciente evoluiu com importante melhora clínica, resolução da artrite, regressão das lesões de pele e melhora da anemia e das provas de atividade inflamatória.

Psoriatic arthritis (PA) is an inflammatory seronegative arthritis of unknown origin. Classically, PA has five clinical forms, and asymmetric oligoarthritis is the most common type. We describe the case of a patient with PA refractory to disease-modifying drugs, who developed drug-induced hepatitis after chemoprophylaxis with isoniazid, administered prior to the treatment with an anti-TNFα agent. Due to the risk of activating latent tuberculosis with the administration of anti-TNFα and hepatotoxicity onset caused by the TB treatment and based on the fact that the treatment of PA is similar to the treatment of rheumatoid arthritis, a decision was made to use the empirical treatment with abatacept. Approximately twenty days after the second infusion of the drug, the patient showed clinical improvement, resolution of the arthritis, almost complete disappearance of the skin lesions and improvement of anemia and inflammatory tests.