Phase I Trial of Cemiplimab, Radiotherapy, Cyclophosphamide, and Granulocyte Macrophage Colony-Stimulating Factor in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

LESSONS LEARNED

Cemiplimab in combination with radiation therapy, cyclophosphamide, and granulocyte macrophage colony-stimulating factor did not demonstrate efficacy above what can be achieved with other PD-1 inhibitor monotherapies in patients with refractory and metastatic head and neck squamous cell carcinoma. The safety profile of cemiplimab combination therapy was consistent with previously reported safety profiles of cemiplimab monotherapy. No new safety signal was observed.

BACKGROUND

Refractory and metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) generally does not respond to PD-1 inhibitor monotherapy. Cemiplimab is a human anti-PD-1 monoclonal antibody. An expansion cohort enrolled patients with R/M HNSCC in a phase I study combining cemiplimab plus radiation therapy (RT), cyclophosphamide, and granulocyte macrophage colony-stimulating factor (GM-CSF).

METHODS

Patients with R/M HNSCC refractory to at least first-line therapy and for whom palliative RT is clinically indicated received cemiplimab plus RT, cyclophosphamide, and GM-CSF. The co-primary objectives were the safety, tolerability, and efficacy of cemiplimab plus RT, cyclophosphamide, and GM-CSF in 15 patients with R/M HNSCC.

RESULTS

Fifteen patients were enrolled. Patients discontinued treatment due to progression of disease. The most common treatment-emergent adverse events (TEAEs) of any grade were fatigue (40.0%), constipation (26.7%), and asthenia, dyspnea, maculo-papular rash, and pneumonia (each 20%). The only grade ≥3 TEAE that occurred in two patients was pneumonia (13.3%). By investigator assessment, there was one partial response (6.7%); disease control rate was 40.0% (95% confidence interval [CI], 16.3-67.7; five patients with stable disease); seven patients had progressive disease, and two were not evaluable. Median progression-free survival by investigator assessment was 1.8 months (95% CI, 1.7-4.7).

CONCLUSION

The regimen demonstrated tolerability but not efficacy above that which can be achieved with anti-PD-1 inhibitor monotherapy for R/M HNSCC.

Health-related quality of life (HRQoL) in patients (pts) with locally advanced basal cell carcinoma (laBCC) treated with cemiplimab: Analysis of a phase II, open-label clinical trial

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Background: Cemiplimab-rwlc is the first immunotherapy to receive approval in the US, fully for pts with laBCC and accelerated for metastatic BCC, post hedgehog inhibitors or for whom hedgehog inhibitors are not appropriate. Cemiplimab resulted in clinically meaningful anti-tumor activity in pts with laBCC who progressed on or were intolerant to hedgehog inhibitor therapy (NCT03132636). This analysis evaluated HRQoL in these pts. Methods: Adults with laBCC and ECOG performance status ≤1 (n=84) received IV cemiplimab 350 mg Q3W for up to 9 treatment cycles. At baseline (BL) and day 1 of each cycle (C), pts completed EORTC QLQ-C30 and SKINDEX-16 questionnaires that assess Global Health Status (GHS)/QoL, functioning, and BCC-related symptoms. Mixed-effects repeated measures (MMRM) models were used to estimate least squares (LS) mean (standard error [SE]) change from BL during treatment (i.e., across C2 to C9); changes ≥|10| points were considered clinically meaningful. Responder analyses were conducted in pts with non-missing data from BL to determine the proportions with clinically meaningful improvement or deterioration, or stability on QLQ-C30 and SKINDEX-16 at C2 and C9; a 10-point threshold was considered meaningful for both instruments. Results: BL scores showed moderate to high levels of functioning and low symptom burden. In MMRM models, overall changes from BL on QLQ-C30 indicated stability for GHS/QoL and all scales except for clinically meaningful worsening of fatigue (LS mean [SE] change 12.5 [3.9]; P<.05). In responder analysis, the majority of pts reported clinically meaningful improvement or stability at C2 and C9 on all QLQ-C30 functioning scales and the key symptom of pain but not fatigue (Table). On SKINDEX-16, MMRM models showed clinically meaningful improvement on the emotional subscale (LS mean [SE] change –13.2 [3.9]; P<.05) and stability on the symptom and functional subscales. Responder analysis showed clinically meaningful improvements or stability across the SKINDEX-16 subscales in approximately 80% of pts at C2, and 70–80% of pts at C9. Conclusions: In laBCC pts treated with cemiplimab, the majority reported clinically meaningful improvement or stability in GHS/QoL and functional status while maintaining a low symptom burden except for fatigue. Clinical trial information: NCT03132636. [Table: see text]

A phase I/II study of REGN5678 (Anti-PSMAxCD28, a costimulatory bispecific antibody) with cemiplimab (anti–PD-1) in patients with metastatic castration-resistant prostate cancer

TPS174

Background: Bispecific antibodies (bsAbs) are emerging as a protein-based therapeutic strategy for directing T-cell-mediated cytotoxicity in a tumor antigen-specific manner, typically by binding to both tumor antigen and the CD3 receptor on T-cells. REGN5678 is a human IgG4-based, first-in-class costimulatory bsAb designed to target prostate tumors by bridging prostate specific membrane antigen expressing tumor cells with the costimulatory receptor, CD28, on T-cells, and providing amplified T-cell receptor-CD3 complex-mediated T-cell activation within the tumor through the activation of CD28 signaling. At the tumor site, REGN5678 may synergize with PD-1 inhibitors. In mouse models, REGN5678 in combination with a PD-1 antibody has improved anti-tumor activity compared with either therapy alone (Waite JC et al. Sci Transl Med. 2020:12;549). Methods: This is an open label, Phase I/II, first-in-human study evaluating safety, tolerability, pharmacokinetics (PK), and anti-tumor activity of REGN5678 alone and in combination with cemiplimab in patients with metastatic castration resistant prostate cancer (mCRPC) who progressed after prior therapy (NCT03972657). For inclusion, patients must have received at least two prior lines of systemic therapy (in addition to androgen deprivation therapy) approved for metastatic and/or castration-resistant disease including a second-generation anti-androgen therapy. REGN5678 is administered weekly; cemiplimab (350 mg) is administered once every 3 weeks. During dose escalation, a 3-week safety lead-in of REGN5678 monotherapy will be administered prior to addition of cemiplimab. Study therapies are administered until disease progression, intolerable adverse events, withdrawal of consent, or study withdrawal criterion is met. The primary objectives in dose escalation are to evaluate safety, tolerability, and PK of REGN5678 alone and in combination with cemiplimab. Expansion cohort(s) will be enrolled once a maximum-tolerated REGN5678/cemiplimab dose is reached, or if a recommended Phase 2 dose or doses have been determined. During the expansion phase, the primary objective is to assess clinical activity, as measured by objective response rate of REGN5678 in combination with cemiplimab per modified Prostate Cancer Working Group 3 criteria. At selected sites, prostate-specific membrane antigen PET/CT scans are performed at baseline and select time points on study. This study is currently open to enrollment. Clinical trial information: NCT03972657.

A phase I/II study of REGN5678 (Anti-PSMAxCD28, a costimulatory bispecific antibody) with cemiplimab (anti-PD-1) in patients with metastatic castration-resistant prostate cancer

TPS5592

Background: Bispecific antibodies (bsAbs) are emerging as a protein-based therapeutic strategy for directing T-cell-mediated cytotoxicity in a tumor antigen-specific manner, typically by binding to both tumor antigen and the CD3 receptor on T cells. REGN5678 is a human IgG4-based, first-in-class costimulatory bsAb designed to target prostate tumors by bridging prostate specific membrane antigen expressing tumor cells with the costimulatory receptor, CD28, on T cells, and providing amplified T-cell receptor-CD3 complex-mediated T-cell activation within the tumor through the activation of CD28 signaling. At the tumor site, REGN5678 may synergize with PD-1 inhibitors. In mouse models, REGN5678 in combination with PD-1 antibody has improved anti-tumor activity compared with either therapy alone (Skokos et al CRI/CICON 2019; oral, session 3). This study evaluates the safety and anti-tumor activity of REGN5678 alone and in combination with cemiplimab in patients with metastatic castration-resistant prostate cancer (mCRPC) who progressed after prior therapy. Methods: This is an open label, Phase I/II, first-in-human study evaluating safety, tolerability, pharmacokinetics (PK), and anti-tumor activity of REGN5678 alone and in combination with cemiplimab in treatment-experienced mCRPC (NCT03972657). For inclusion, patients must have received at least two approved therapies for metastatic disease, including a second-generation hormonal agent. REGN5678 is administered weekly and cemiplimab (350 mg) is administered once every 3 weeks. During dose escalation, a 3-week safety lead-in of REGN5678 monotherapy will be administered prior to the addition of cemiplimab. Study therapies are administered until disease progression, intolerable adverse events, withdrawal of consent, or study withdrawal criterion is met. The primary objectives in dose escalation are to evaluate safety, tolerability, and PK of REGN5678 alone and in combination with cemiplimab. Expansion cohort(s) will be enrolled once a REGN5678/cemiplimab recommended Phase II dose is determined. During the expansion phase, the primary trial objective is to assess clinical activity, as measured by objective response rate of REGN5678 in combination with cemiplimab per modified Prostate Cancer Working Group 3 criteria. This study is currently open to enrollment. Clinical trial information: NCT03972657 .

Tolerability and antitumor activity of cemiplimab, a human monoclonal anti-PD-1, in patients with non-small cell lung cancer (NSCLC): Interim data from a phase I dose escalation and NSCLC expansion cohort

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Background: NSCLC accounts for ~85% of lung cancers; most patients (pts) are at an advanced stage at the time of diagnosis. Cemiplimab (REGN2810) is being investigated for the treatment of NSCLC, in addition to other indications (NCT02383212). Methods: In the dose escalation (DE) phase, enrolled pts with advanced malignancies with no alternative standard-of-care therapeutic option received cemiplimab 1, 3 or 10 mg/kg every 2 weeks (Q2W) intravenously (IV) for up to 48 weeks. In the NSCLC expansion cohort (EC 1), enrolled pts with advanced disease who had relapsed after, or were refractory to at least first-line therapy received cemiplimab 200 mg Q2W IV for up to 48 weeks. Tumor biopsies were performed at baseline (EC 1 only), Day 29 and progression, if possible. Tumor measurements were performed every 8 weeks according to RECIST 1.1. Results: As of Sept 1, 2017, 21 pts with NSCLC (1 in DE at 1 mg/kg; 20 in EC 1) were enrolled; median age was 65.0 years (range, 50–82; 14 M/ 7 F); 81.0% had a ECOG performance status of 1, 19.0% of 0; 13/21 (61.9%) had a histology of adenocarcinoma. The most common treatment-related adverse events (TRAEs) were asthenia, pneumonitis, and rash (each n = 3, 14.3%). Each of the following ≥Grade 3 TRAEs occurred once: pneumonitis, diabetic ketoacidosis, and nephritis. By central independent review, 6 pts had partial response (PR), 6 had stable disease (SD) or non-complete response (CR)/non-progressive disease (PD), and 9 had PD. Overall response rate (ORR; CR + PR) was 28.6%. Duration of response exceeded 8 months in 5 of the 6 responders. Disease control rate (ORR + SD) was 57.1%. Disease control has been maintained for 7 pts after a planned treatment completion at 48 weeks. Of the 17 pts who had tissue available for PD-L1 expression evaluation, 11 (64.7%) had a tumor proportion score (TPS) of < 1%, and 3 (17.6) had a TPS of > 50%. Conclusions: Cemiplimab showed an acceptable safety profile and demonstrated antitumor activity in pretreated pts with NSCLC. Pivotal trials of cemiplimab as monotherapy or in combination with other treatments in pts with advanced NSCLC are currently enrolling (NCT03088540; NCT03409614). Clinical trial information: NCT02383212.

Cemiplimab (REGN2810): A fully human anti-PD-1 monoclonal antibody for patients with unresectable locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC)—Initial safety and efficacy from expansion cohorts (ECs) of phase I study

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Background: There is no established standard of care for unresectable locally advanced or metastatic CSCC. UV-induced DNA damage causes hypermutation in most CSCCs. Therefore, these tumors may be responsive to PD-1 checkpoint blockade. In the dose escalation portion of the phase 1 study of cemiplimab (REGN2810), a durable (19 + months) radiologic complete response was observed in a patient (pt) with metastatic CSCC (ASCO 2015, #3024). Methods: ECs enrolled pts with distantly metastatic (EC 7) and locally advanced (EC 8) CSCC. All patients received cemiplimab 3 mg/kg by intravenous infusion over 30 minutes every 2 weeks for up to 48 weeks. Research biopsies were performed at baseline and Day 29 (and at progression, if possible). Tumor measurements were performed every 8 weeks according to RECIST 1.1 to determine overall response rate (ORR). Data cutoff date was 31 Jan 2017. Results: 26 pts were enrolled (10 in EC 7 and 16 in EC 8): median age, 72.5 y (range, 56–88y); median PS 1 (range, 0–1); 21M:5F; median number of prior systemic therapy regimens, 1 (range, 0–2). Median exposure to cemiplimab was 7 doses (range, 1–22). The most common treatment-related adverse event of any grade was fatigue (19.2%). Each of the following ≥ Grade 3 related AEs occurred once: AST elevation, ALT elevation, arthralgia, and rash. ORR (PR + CR, including unconfirmed) and disease control rate (ORR+SD) were 52% (12/23; 4uPR, 5 PR, 2CR, 1 uCR) and 70% (16/23, including 4SD), respectively. Three patients are not yet evaluable. Median PFS and OS have not been reached, and only one patient has experienced PD during cemiplimab treatment after initial response. Correlative studies are in process, including PD-L1 status and whole exome tumor DNA sequencing. Conclusions: Cemiplimab is well tolerated and produces antitumor activity in patients with advanced CSCC. A pivotal trial of cemiplimab for patients with advanced CSCC is enrolling patients. Clinical trial information: NCT02383212.

REGN2810: A fully human anti-PD-1 monoclonal antibody, for patients with unresectable locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC)—Initial safety and efficacy from expansion cohorts (ECs) of phase I study

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Background: There is no established standard of care for unresectable locally advanced or metastatic CSCC. UV-induced DNA damage causes hypermutation in most CSCCs. Therefore, these tumors may be responsive to PD-1 checkpoint blockade. In the dose escalation portion of the phase 1 study of REGN2810, a durable (19 + months) radiologic complete response was observed in a patient (pt) with metastatic CSCC (ASCO 2015, #3024). Methods: ECs enrolled pts with distantly metastatic (EC 7) and locally advanced (EC 8) CSCC. All patients received 3 mg/kg REGN2810 by intravenous infusion over 30 minutes every 2 weeks for up to 48 weeks. Research biopsies were performed at baseline and Day 29 (and at progression, if possible). Tumor measurements were performed every 8 weeks according to RECIST 1.1 to determine overall response rate (ORR). Data cutoff date was 31 Jan 2017. Results: 26 pts were enrolled (10 in EC 7 and 16 in EC 8): median age, 72.5 y (range, 56-88y); median PS 1 (range, 0 – 1); 21M:5F; median number of prior systemic therapy regimens, 1 (range, 0 – 2). Median exposure to REGN2810 was 7 doses (range, 1-22). The most common treatment-related adverse event of any grade was fatigue (19.2%). Each of the following ≥ Grade 3 related AEs occurred once: AST elevation, ALT elevation, arthralgia, and rash. ORR (PR + CR, including unconfirmed) and disease control rate (ORR+SD) were 52% (12/23; 4uPR, 5 PR, 2CR, 1 uCR) and 70% (16/23, including 4SD), respectively. Three patients are not yet evaluable. Median PFS and OS have not been reached, and only one patient has experienced PD during REGN2810 treatment after initial response. Correlative studies are in process, including PD-L1 status and whole exome tumor DNA sequencing. Conclusions: REGN2810 is well tolerated and produces antitumor activity in patients with advanced CSCC. A pivotal trial of REGN2810 for patients with advanced CSCC is enrolling patients (NCT02760498). Clinical trial information: NCT02383212.

Positron emission tomography in pediatric neurology

Positron emission tomography (PET) is an accurate and relatively noninvasive way of studying brain activity using systemically administered tracers labeled with positron emitting isotopes. In pediatric neurology, it has great scope not only to elucidate the complexities of the developing brain but also to understand disease processes and characterize biological risk factors. Its greatest clinical utility lies in the field of epilepsy where it is used (in patients with intractable partial epilepsy) to localize epileptogenic foci for surgical resection. In addition, functional brain mapping using PET is increasingly being used to reliably and accurately identify speech and sensory-motor areas to minimize postoperative morbidity. PET is also useful in evaluating neurodegenerative disorders and cognitive abnormalities when magnetic resonance imaging scans are unrevealing. The technology continues to progress rapidly through improvements in imaging and radiopharmacology with potential applications in neurooncology, cerebral vascular disease, and metabolic diseases.

Diagnostic utility of video EEG monitoring in paroxysmal events

OBJECTIVES

A retrospective study was conducted to evaluate clinical usefulness of video EEG monitoring in patients with suspected epileptic seizures.

MATERIAL AND METHODS

A total of 444 patients who had diagnostic video EEG from January 1989 to December 1992 were studied after excluding those with known medically refractory focal epilepsy undergoing presurgical evaluation. Most were outpatients and had video EEG monitoring during normal working hours over 1-5 days.

RESULTS

The procedure had a success rate of 73%; characteristic events were captured and categorized in 53% of the patients. Patients with an event frequency of at least one per week or those who had events characterized by motor manifestations showed a higher yield. Thirty-two percent of the patients had psychogenic seizures. Thirty-four percent of the patients had either epileptic seizures recorded during the study or showed clear-cut interictal epileptiform abnormalities providing strong evidence of underlying epileptic process.

CONCLUSION

In patients with frequent paroxysmal events, a video EEG study provides diagnostically critical information. It can be performed usually as an outpatient investigation.

Diagnostic criteria for tuberculous meningitis and their validation

SETTING

Tuberculous meningitis (TBM) has high morbidity and mortality. Demonstration of tubercle bacilli in cerebrospinal fluid (CSF), the only reliable method of diagnosis, is time consuming and has a low yield. Early diagnosis and treatment are of utmost importance for favourable outcome.

OBJECTIVE

The study was conceived to define easy to use criteria.

METHODS

A set of criteria using clinical features, CSF examination and computed tomography (CT) findings were defined. 76 patients suspected of having TBM were divided into definite, highly probable, probable and possible TBM based on the criteria. The validity of criteria was tested using information from bacterial isolation, polymerase chain reaction (PCR) test for tuberculosis, response to treatment and autopsy.

RESULTS

PCR was positive in over 75% of patients in the highly probable and probable groups. 91% of patients with highly probable and 66% with probable TBM improved on antituberculosis therapy.

CONCLUSION

The criteria are reliable in making early diagnosis of TBM.

Hemiplegia in posterior cerebral artery strokes

Hemiplegia is an unusual presenting feature of posterior circulation strokes. We report five cases who presented with hemiplegia and in whom CT scans revealed evidence of infarcts in posterior cerebral artery territory.

Rapid diagnosis of tuberculous meningitis by polymerase chain reaction

The polymerase chain reaction (PCR) in cerebrospinal fluid was compared with conventional bacteriology and an enzyme-linked immunosorbent assay (ELISA) for cerebrospinal fluid antibodies in the diagnosis of tuberculous meningitis (TBM). PCR was the most sensitive technique; it detected 15 (75%) of 20 cases of highly probable TBM (based on clinical features), 4 (57%) of 7 probable cases, and 3 (43%) of 7 possible cases. ELISA detected 11 (55%) of the highly probable cases and 2 each of the probable and possible cases. Culture was positive in only 4 of the highly probable cases. Among the controls (14 pyogenic meningitis, 3 aseptic meningitis, 34 other neurological disorders), 6 subjects tested early in the study (2 pyogenic meningitis, 4 other disorders) were PCR positive. Second DNA preparations from their stored cerebrospinal fluid samples were all PCR negative, suggesting that the false-positive results were due to cross-contamination. 18 PCR-positive TBM samples retested were all still PCR positive. The antibody ELISA was positive in 3 controls despite the use of a high cutoff value.

Conceptual design of a cellular filter to remove trace viral contaminants in blood

Various process alternatives and designs of using a filter containing cellular adsorbents to remove trace viral contaminants from blood and other protein solutions have been studied. Sterilization charts have been developed that can be used to estimate the filter size required to achieve a desired sterilization criterion. A parametric study was carried out to identify various process parameters that may affect this physical trace removal process. It has been demonstrated that the adsorption rate constant is a critical parameter in the design of an efficient cellular filter for viral contaminant removal. This constant is characteristic of the virus-cell system under consideration and is shown to be particularly sensitive to the cell surface receptor density, adsorbent diameter, and fluid flow rate. Higher log titer reduction in virus concentrations can be achieved with low flow rates and no recycle. Preliminary analyses indicate the feasibility of using a magnetically stabilized fluidized filter (MSFF) reactor design for effective virus removal from these complex solutions.

Computed tomography--a reliable diagnostic modality in pulmonary asbestosis

Forty-six individuals with documented asbestos exposure were studied by computed tomography as part of their initial evaluation. CT sections were compared to standard chest radiographs and pulmonary function tests. The results showed computed tomography to be able to detect early signs of asbestosis in patients with inconclusive conventional radiographs or intact pulmonary function tests, the same as to demonstrate extensive pulmonary pathology in long-standing cases.

Intralobar pulmonary sequestration in conjunction with bronchial isomerism

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Analgesics and asthma

Aspirin and many other analgesics may be hazardous for some patients with asthma. These patients, numbering approximately 10% to 15% of all asthmatics, have a clinical course that has been well characterized. The diagnosis is usually made from the history, but sometimes it requires analgesic challenge tests. The pathogenesis remains controversial. It appears that the analgesics responsible for the syndrome inhibit prostaglandin synthesis, and this action in turn causes the release of potent bronchoconstrictors such as SRS-A, histamine, or kinins. Usually, recognition of the syndrome and careful avoidance of prostaglandin synthesis inhibitors in affected patients are the two steps needed for effective management. Persistent symptoms, however, may require aminophylline, corticosteroids, and disodium cromoglycate as well. Recent developments may allow these patients to use substituted aspirin analogues or even aspirin itself under certain conditions. Further investigation of the prostaglandins may promote a better understanding of asthma.