Intraindividual Comparisons to Determine Comparative Effectiveness: Their Relevance for G-BA's Health Technology Assessments

OBJECTIVES

Health technology assessments (HTA) rely on head-to-head comparisons. We searched for intraindividual comparisons (IIC) qualifying as head-to-head design to develop comparative evidence.

METHODS

Gemeinsamer Bundesausschuss (G-BA) appraisals between January 2011 and April 2020 were reviewed for inclusion of IIC. Identified IIC were grouped according to disease characteristics into nonprogressive, progressive, irregular, or symmetrical conditions. Evaluation of IIC by Institut für Qualität und Wirschaftlichkeit im Gesundheitswesen (IQWIG) and acceptance of IIC by G-BA were determined, and criteria for the usage and quality of IIC were developed.

RESULTS

A total of 483 appraisals finalized between January 2011 and April 2020 were reviewed. Eleven appraisals included IIC: nonacog beta (hemophilia B), turoctocog alpha (hemophilia A), emicizumab (2 appraisals: hemophilia A), pasireotide (unresectable pituitary tumor), lomitapid (homozygous familial hypercholesterolemia), glycerol phenylbutyrate (2 appraisals: urea cycle disorders), asfotase alfa (hypophosphatasia), lumacaftor (cystic fibrosis), and larotrectinib (NTRK⁺ solid tumors). All those appraisals related to rare genetic conditions with hemophilia and its bleeding rate are considered mainly a nonprogressive condition. All the other diseases show progressive disease characteristics. None of the identified IIC has been accepted by G-BA. Inconsistencies of before/after study design, lack of clarity on treatments prior to the switch, and different time intervals were among the most commonly cited methodological concerns.

CONCLUSIONS

IICs provide a rare opportunity to determine comparative effectiveness in distinct clinical settings that are not suitable or difficult to randomize into parallel groups. While manufacturers and researchers should aim for highest methodological standards when running an IIC, HTA bodies should accept IIC in distinct settings when determining relative effectiveness.

Efficacy of emicizumab prophylaxis versus factor VIII prophylaxis for treatment of hemophilia A without inhibitors: network meta-analysis and sub-group analyses of the intra-patient comparison of the HAVEN 3 trial

Objectives: To compare the efficacy of emicizumab prophylaxis with that of factor VIII (FVIII) prophylaxis in patients with hemophilia A without inhibitors using two approaches: network meta-analyses (NMA) and additional sub-group analyses from the HAVEN 3 trial.Methods: The NMA used data from trials identified using a systematic literature review and compared bleed rates in patients receiving emicizumab prophylaxis and patients receiving FVIII prophylaxis using a Bayesian, random effects generalized linear model with log link Poisson likelihood. Additional sub-groups of the HAVEN 3 trial included here were defined as patients whose dose-taking behavior met either European label or World Federation of Hemophilia guidelines. A negative binomial regression model was used to conduct an intra-patient comparison of bleed rates within the sub-groups, during treatment with FVIII prophylaxis before entering HAVEN 3 and treatment with emicizumab prophylaxis during HAVEN 3.Results: Four studies were included in the base-case NMA. Evidence showed that the total treated bleed rate was lower with emicizumab prophylaxis compared with FVIII prophylaxis (rate ratio [RR] = 0.36 [95% credible interval (CrI) = 0.13-0.95]). Similar associations were observed in sensitivity analyses. The additional HAVEN 3 analyses also showed lower rates of treated bleeds with emicizumab prophylaxis than with FVIII prophylaxis (RRs [95% confidence interval (CI)] = 0.380 [0.186-0.790] and 0.472 [0.258-0.866] in two sub-groups). These results confirm the original HAVEN 3 intra-patient comparison findings.Conclusions: Combined findings from NMA and additional sub-group analyses of HAVEN 3 support the superiority of emicizumab prophylaxis over FVIII prophylaxis in patients with hemophilia A without inhibitors.

Non-persistence and non-adherence to MTX therapy in patients with rheumatoid arthritis: a retrospective cohort study based on German RA patients

OBJECTIVE

This study aimed to assess the level of nonpersistence (NP) and nonadherence (NA) to methotrexate (MTX) therapy in German patients with rheumatoid arthritis (RA).

MATERIALS AND METHODS

Based on German claims data, RA patients who received a MTX therapy (subgroup: treatment-naive patients) were analyzed. NP was defined as treatment gap >12 weeks. Regarding NA, it is the overall medication possession ratio (MPR) during an observational period of 12 or 24 months after therapy, and the MPR is calculated only for the periods of therapy continuation; NA was defined as MPR <80%.

RESULTS

A total of 7,146 RA patients who received at least one MTX prescription (subgroup: 1,211 treatment-naive patients) could be observed (mean age: 64.4 years, 73.6% female). Percentage of NP patients among MTX-naive patients after 6, 12 and 18 months was 16.7%, 34.0% and 36.7%, respectively. After MTX therapy discontinuation, 39.9% had restarted their MTX therapy, 13.8% had received another non-MTX synthetic disease-modifying antirheumatic drug (sDMARD), 8.1% had biological DMARD (bDMARD) and 49.2% had not received any DMARD prescription at all. Overall, 12- and 24-month MPRs for MTX therapy were 83.0% and 76.5% with a percentage of NA patients of 25.8% and 33.8%, respectively. During periods of general treatment continuation, the percentage of patients with an MPR <80% was 6.5%.

CONCLUSION

NP to MTX treatment seems to be common in one-fourth of German patients with RA. An additional number of patients, at least 6.5%, are also affected by NA. A considerable percentage of RA patients who discontinued MTX therapy do not receive any follow-up DMARD therapy.

Inhibition of soluble adenylyl cyclase increases the radiosensitivity of prostate cancer cells

Pharmacological modulation of tumor radiosensitivity is a promising strategy for enhancing the outcome of radiotherapy. cAMP signaling plays an essential role in modulating the proliferation and apoptosis of different cell types, including cancer cells. Until now, the regulation of this pathway was restricted to the transmembrane class of adenylyl cyclases. In the present study, the role of an alternative source of cAMP, the intracellular localized soluble adenylyl cyclase (sAC), in the radiosensitivity of prostate cancer cells was investigated. Pharmacological inhibition of sAC activity led to marked suppression of proliferation, lactate dehydrogenase release, and induction of apoptosis. The combination of ionizing radiation with partial suppression of sAC activity (~50%) immediately after irradiation synergistically inhibited proliferation and induced apoptosis. Overexpression of sAC in normal prostate epithelial PNT2 cells increased the cAMP content and accelerated cell proliferation under control conditions. The effects of radiation were significantly reduced in transformed PNT2 cells compared with control cells. Analysis of the underlying cellular mechanisms of sAC-induced radioresistance revealed the sAC-dependent activation of B-Raf/ERK1/2 signaling. In agreement with this finding, inhibition of ERK1/2 in prostate cancer cells enhanced the cytotoxic effect of irradiation. In conclusion, the present study suggests that sAC-dependent signaling plays an important role in the radioresistance of prostate cancer cells. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.

Type 10 soluble adenylyl cyclase is overexpressed in prostate carcinoma and controls proliferation of prostate cancer cells

cAMP signaling plays an essential role in modulating the proliferation of different cell types, including cancer cells. Until now, the regulation of this pathway was restricted to the transmembrane class of adenylyl cyclases. In this study, significant overexpression of soluble adenylyl cyclase (sAC), an alternative source of cAMP, was found in human prostate carcinoma, and therefore, the contribution of this cyclase was investigated in the prostate carcinoma cell lines LNCaP and PC3. Suppression of sAC activity by treatment with the sAC-specific inhibitor KH7 or by sAC-specific knockdown mediated by siRNA or shRNA transfection prevented the proliferation of prostate carcinoma cells, led to lactate dehydrogenase release, and induced apoptosis. Cell cycle analysis revealed a significant rise in the G(2) phase population 12 h after sAC inhibition, which was accompanied by the down-regulation of cyclin B(1) and CDK1. sAC-dependent regulation of proliferation involves the EPAC/Rap1/B-Raf signaling pathway. In contrast, protein kinase A does not play a role. In conclusion, this study suggests a novel sAC-dependent signaling pathway that controls the proliferation of prostate carcinoma cells.

Type 10 adenylyl cyclase mediates mitochondrial Bax translocation and apoptosis of adult rat cardiomyocytes under simulated ischaemia/reperfusion

AIMS

Apoptosis of cardiomyocytes significantly contributes to the development of post-ischaemic cardiomyopathy. Although mitochondria have been suggested to play a crucial role in this process, the precise mechanisms controlling the mitochondria-dependent apoptosis in cardiomyocytes under ischaemia/reperfusion are still poorly understood. Here we aimed to analyse the role of the soluble adenylyl cyclase (sAC).

METHODS AND RESULTS

Adult rat cardiomyocytes were subjected to simulated in vitro ischaemia (SI) consisting of glucose-free anoxia at pH 6.4. Apoptosis was detected by DNA laddering, chromatin condensation, and caspases cleavage. SI led to the translocation of sAC to the mitochondria and mitochondrial depolarization followed by cytochrome c release, caspase-9/-3 cleavage and apoptosis during simulated reperfusion (SR). Pharmacological inhibition of sAC during SI, but not during SR, significantly reduced the SI/SR-induced mitochondrial injury and apoptosis. Similarly, sAC knock-down mediated by an adenovirus coding for shRNA targeting sAC prevented the activation of the mitochondrial pathway of apoptosis. Analysis of the link between sAC and apoptosis revealed a sAC and protein kinase A-dependent Bax phosphorylation at Thr(167) and its translocation to mitochondria during SI, which subsequently caused mitochondrial oxygen radical formation followed by cytochrome c release and caspase-9 cleavage during SR.

CONCLUSION

These results suggest a key role of sAC in SI-induced mitochondrial Bax translocation and activation of the mitochondrial pathway of apoptosis in adult cardiomyocytes.

SLC4A7 sodium bicarbonate co-transporter controls mitochondrial apoptosis in ischaemic coronary endothelial cells

AIMS

Bicarbonate transport has been shown to participate in apoptosis under ischaemic stress. However, the precise transporting mechanisms involved in ischaemic apoptosis are unknown and were thus the aim of the present study.

METHODS AND RESULTS

Rat coronary endothelial cells (EC) were exposed to simulated in vitro ischaemia for 2 h, and apoptosis was subsequently determined by chromatin staining and caspase-3 activity analysis. By examining the expression of bicarbonate transporters (BT) in EC by reverse transcriptase polymerase chain reaction and western blotting, a marked expression of the electroneutral sodium bicarbonate co-transporter (SLC4A7) was defined. To analyse the potential role of this transporter during apoptosis, a selective inhibitor (S0859, Sanofi-Aventis) was applied. Treatment with S0859 significantly increased caspase-3 activity and elevated the number of apoptotic EC. These results were comparable with an unselective inhibition of all BT due to withdrawal of bicarbonate in the anoxic medium. Knockdown of SLC4A7 in EC by transfecting appropriate siRNA similarly increased apoptosis of EC under simulated ischaemia. The initial characterization of the participating mechanisms of SLC4A7-dependent apoptosis revealed an activation of the mitochondrial pathway of apoptosis, i.e. cleavage of caspase-9 and binding of Bax to mitochondria. In contrast, no activation of the endoplasmic reticulum-dependent pathway (caspase-12 cleavage) or the extrinsic apoptotic pathway (caspase-8 cleavage) was found. Finally, a mitochondrial localization of SLC4A7 was demonstrated.

CONCLUSION

The electroneutral sodium bicarbonate co-transporter SLC4A7 localizes in mitochondria and suppresses the ischaemia-induced activation of the mitochondrial pathway of apoptosis in coronary EC.

Soluble adenylyl cyclase controls mitochondria-dependent apoptosis in coronary endothelial cells

The cAMP signaling pathway plays an essential role in modulating the apoptotic response to various stress stimuli. Until now, it was attributed exclusively to the activity of the G-protein-responsive transmembrane adenylyl cyclase. In addition to transmembrane AC, mammalian cells possess a second source of cAMP, the ubiquitously expressed soluble adenylyl cyclase (sAC). However, the role of this cyclase in apoptosis was unknown. A mitochondrial localization of this cyclase has recently been demonstrated, which led us to the hypothesis that sAC may play a role in apoptosis through modulation of mitochondria-dependent apoptosis. To prove this hypothesis, apoptosis was induced by simulated in vitro ischemia or by acidosis, which is an important component of ischemia. Suppression of sAC activity with the selective inhibitor KH7 or sAC knockdown by small interfering RNA transfection abolished endothelial apoptosis. Furthermore, pharmacological inhibition or knockdown of protein kinase A, an important cAMP target, demonstrated a significant anti-apoptotic effect. Analysis of the underlying mechanisms revealed (i) the translocation of sAC to mitochondria under acidic stress and (ii) activation of the mitochondrial pathway of apoptosis, i.e. cytochrome c release and caspase-9 cleavage. sAC inhibition or knockdown abolished the activation of the mitochondrial pathway of apoptosis. Analysis of mitochondrial co-localization of Bcl-2 family proteins demonstrated sAC- and protein kinase A-dependent translocation of Bax to mitochondria. Taken together, these results suggest the important role of sAC in modulating the mitochondria-dependent pathway of apoptosis in endothelial cells.

Acidic preconditioning protects endothelial cells against apoptosis through p38- and Akt-dependent Bcl-xL overexpression

To analyze the underlying cellular mechanisms of adaptation to ischemia-induced apoptosis through short acidic pretreatment, i.e. acidic preconditioning (APC), Wistar rat coronary endothelial cells (EC) were exposed for 40 min to acidosis (pH 6.4) followed by a 14 h recovery period (pH 7.4) and finally treated for 2 h with simulated in vitro ischemia (glucose-free anoxia at pH 6.4). APC led to a transient activation of p38 and Akt kinases, but not of JNK and ERK1/2 kinases, which was accompanied by significant reduction of the apoptotic cell number, caspase-12/-3 cleavage and Bcl-xL overexpression. These effects of APC were completely abolished by prevention of Akt- or p38-phosphorylation during APC. Furthermore, knock-down of Bcl-xL by siRNA-transfection also abolished the anti-apoptotic effect of APC. Therefore, APC leads to protection of EC against ischemic apoptosis by activation of Akt and p38 followed by overexpression of Bcl-xL, which is a key anti-apoptotic mechanism of APC.