The CTLA-4 x OX40 bispecific antibody ATOR-1015 induces anti-tumor effects through tumor-directed immune activation.

BACKGROUND: The CTLA-4 blocking antibody ipilimumab has demonstrated substantial and durable effects in patients with melanoma. While CTLA-4 therapy, both as monotherapy and in combination with PD-1 targeting therapies, has great potential in many indications, the toxicities of the current treatment regimens may limit their use. Thus, there is a medical need for new CTLA-4 targeting therapies with improved benefit-risk profile. METHODS: ATOR-1015 is a human CTLA-4 x OX40 targeting IgG1 bispecific antibody generated by linking an optimized version of the Ig-like V-type domain of human CD86, a natural CTLA-4 ligand, to an agonistic OX40 antibody. In vitro evaluation of T-cell activation and T regulatory cell (Treg) depletion was performed using purified cells from healthy human donors or cell lines. In vivo anti-tumor responses were studied using human OX40 transgenic (knock-in) mice with established syngeneic tumors. Tumors and spleens from treated mice were analyzed for CD8+ T cell and Treg frequencies, T-cell activation markers and tumor localization using flow cytometry. RESULTS: ATOR-1015 induces T-cell activation and Treg depletion in vitro. Treatment with ATOR-1015 reduces tumor growth and improves survival in several syngeneic tumor models, including bladder, colon and pancreas cancer models. It is further demonstrated that ATOR-1015 induces tumor-specific and long-term immunological memory and enhances the response to PD-1 inhibition. Moreover, ATOR-1015 localizes to the tumor area where it reduces the frequency of Tregs and increases the number and activation of CD8+ T cells. CONCLUSIONS: By targeting CTLA-4 and OX40 simultaneously, ATOR-1015 is directed to the tumor area where it induces enhanced immune activation, and thus has the potential to be a next generation CTLA-4 targeting therapy with improved clinical efficacy and reduced toxicity. ATOR-1015 is also expected to act synergistically with anti-PD-1/PD-L1 therapy. The pre-clinical data support clinical development of ATOR-1015, and a first-in-human trial has started (NCT03782467).

Expression, activity and localization of lysosomal sulfatases in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a leading cause of death world-wide. Recently, we showed that COPD is associated with gene polymorphisms in SUMF1, a master regulator of sulfatases. Sulfatases are involved in extracellular matrix remodeling and activated by SUMF1, but their role in the lung is poorly described. We aimed to examine how sulfatases are affected in the airways of patients with COPD compared to ever smokers and never smokers. We observed that mRNA expression of the sulfatases GALNS, GNS and IDS was increased, while protein expression of many sulfatases was decreased in COPD fibroblasts. Several sulfatases, including GALNS, IDS, and SGSH, showed increased activity in COPD fibroblasts. Examination of different sulfatases by immunofluorescence showed that IDS, ARSB, GNS and SGSH in fibroblasts were localized to sites other than their reported destination. Using a master panel from different organs, RNA expression of all sulfatases could be observed in lung tissue. Additionally, immunohistochemistry on lung biopsies indicated differing expression of sulfatases in COPD patients. In conclusion, mRNA, protein expression, sulfatase activity levels, and localization of sulfatases are altered in lung fibroblasts and lung tissue from COPD patients and may be mechanistically important in COPD pathogenesis. This could contribute to the understanding of the disease mechanism in COPD and in the long run, to lead to more individualized therapies.

[Postural orthostatic tachycardia syndrome]. / Posturalt ortostatiskt takykardisyndrom ­ handikappande tillstånd som främst drabbar kvinnor.

Postural orthostatic tachycardia syndrome (POTS) is a condition where the patient experiences tachycardia (a rise in heart rate of at least 30 beats per minute, 40 in people between the ages of 12 and 19) upon assuming the upright position, in the absence of orthostatic hypotension (a fall in systolic blood pressure of more than 20 mmHg). The majority of patients are young women. Symptoms are experienced frequently during standing, and include dizziness, fatigue, palpitations, tremulousness, blurred vision and sometimes syncope - although presyncope is more common. The diagnosis requires that symptoms have been present for at least six months and lack another medical explanation. The pathophysiology is believed to be multifactorial; peripheral sympathetic denervation, excessive sympathetic drive, hypovolemia and deconditioning have been reported in POTS. Patient education is fundamental in the management of POTS, including information regarding symptoms and exacerbating factors as well as methods for increasing arterial pressure. Exercise is believed to be effective. Several drugs can be used to relieve symptoms, although none of them are licensed for the treatment of POTS. We describe a case that illustrates that POTS can be debilitating, which requires awareness of the condition among clinicians.

Endoplasmic reticulum, Golgi, and lysosomes are disorganized in lung fibroblasts from chronic obstructive pulmonary disease patients.

Chronic Obstructive Pulmonary Disease (COPD) is often caused by smoking and other stressors. This causes oxidative stress, which induces numerous changes on both the transcriptome and proteome of the cell. We aimed to examine if the endomembrane pathway, including the endoplasmic reticulum (ER), Golgi, and lysosomes, was disrupted in fibroblasts from COPD patients as opposed to healthy ever-smokers or never-smokers, and if the response to stress differed. Different cellular compartments involved in the endomembrane pathway, as well as mRNA expression and apoptosis, were examined before and after the addition of stress in lung fibroblasts from never-smokers, ever-smokers, and patients with COPD. We found that the ER, Golgi, and lysosomes were disorganized in fibroblasts from COPD patients under baseline conditions. After a time course with ER stress inducing chemicals, changes to the phenotypes of cellular compartments in COPD patient fibroblasts were observed, and the expression of the ER stress-induced gene ERP72 was upregulated more in the COPD patient's cells compared to ever-smokers or never-smokers. Lastly, a tendency of increased active Caspase-3 was observed in COPD fibroblasts. Our results show that COPD patients have phenotypic changes in the lung fibroblasts endomembrane pathway, and respond differently to stress. Furthermore, these fibroblasts were cultured for several weeks outside the body, but they were not able to regain proper ER structure, indicating that the internal changes to the endomembrane system are permanent in smokers. This vulnerability to cellular stress might be a cause as to why some smokers develop COPD.

Club cell protein (CC16) in plasma, bronchial brushes, BAL and urine following an inhaled allergen challenge in allergic asthmatics.

BACKGROUND: Club cell protein (CC16) is a pneumoprotein secreted by epithelial club cells. CC16 possesses anti-inflammatory properties and is a potential biomarker for airway epithelial damage. We studied the effect of inhaled allergen on pulmonary and systemic CC16 levels. METHODS: Thirty-four subjects with allergic asthma underwent an inhaled allergen challenge. Bronchoscopy with bronchoalveolar lavage (BAL) and brushings was performed before and 24 h after the challenge. CC16 was quantified in BAL and CC16 positive cells and CC16 mRNA in bronchial brushings. CC16 was measured in plasma and urine before and repeatedly after the challenge. Thirty subjects performed a mannitol inhalation challenge prior to the allergen challenge. RESULTS: Compared to baseline, CC16 in plasma was significantly increased in all subjects 0-1 h after the allergen challenge, while CC16 in BAL was only increased in subjects without a late allergic response. Levels of CC16 in plasma and in the alveolar fraction of BAL correlated significantly after the challenge. There was no increase in urinary levels of CC16 post-challenge. Mannitol responsiveness was greater in subjects with lower baseline levels of CC16 in plasma. CONCLUSIONS: The increase in plasma CC16 following inhaled allergen supports the notion of CC16 as a biomarker of epithelial dysfunction.