Final analysis of phase II results with cemiplimab in metastatic basal cell carcinoma after hedgehog pathway inhibitors

BACKGROUND

Metastatic basal cell carcinoma (mBCC) is a rare condition with no effective second-line treatment options. Cemiplimab is an immune checkpoint inhibitor that blocks the binding of programmed cell death-1 (PD-1) to its ligands, programmed death-ligand 1 (PD-L1) and programmed death-ligand 2 (PD-L2). Here, we present the final analysis of cemiplimab in patients with mBCC after first-line hedgehog pathway inhibitor (HHI) treatment (NCT03132636).

PATIENTS AND METHODS

In this open-label, single-arm, phase II study, adults with mBCC and Eastern Cooperative Oncology Group performance status ≤1, post-HHI treatment, received cemiplimab 350 mg intravenously every 3 weeks for ≤93 weeks or until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by independent central review (ICR). Duration of response (DOR) was a key secondary endpoint. Other secondary endpoints were ORR per investigator assessment, progression-free survival (PFS), overall survival (OS), complete response rate, safety, and tolerability.

RESULTS

Fifty-four patients were enrolled: 70% were male and the median age of patients was 64 [interquartile range (IQR) 57.0-73.0] years. The median duration of follow-up was 8 months (IQR 4-21 months). The ORR per ICR was 22% [95% confidence interval (CI) 12% to 36%], with 2 complete responses and 10 partial responses. Among responders, the median time to response per ICR was 3 months (IQR 2-7 months). The estimated median DOR per ICR was not reached [95% CI 10 months-not evaluable (NE)]. The disease control rate was 63% (95% CI 49% to 76%) per ICR and 70% (95% CI 56% to 82%) per investigator assessment. The median PFS per ICR was 10 months (95% CI 4-16 months); the median OS was 50 months (95% CI 28 months-NE). The most common treatment-emergent adverse events were fatigue [23 (43%)] and diarrhoea [20 (37%)]. There were no treatment-related deaths.

CONCLUSIONS

Cemiplimab demonstrated clinically meaningful antitumour activity, including durable responses, and an acceptable safety profile in patients with mBCC who had disease progression on or intolerance to HHI therapy.

A phase II study of temsirolimus added to low-dose weekly carboplatin and paclitaxel for patients with recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC)

Background

Activating events along the PI3K/mTOR pathway are common in head and neck squamous cell carcinomas (HNSCC), and preclinical studies suggest additive or synergistic effects when combining mTORC1 inhibitors with carboplatin and paclitaxel chemotherapy.

Patients and methods

In this single-institution phase II study, the combination of temsirolimus 25 mg, carboplatin AUC 1.5, and paclitaxel 80 mg/m2 administered on days 1 and 8 of a 21-day cycle was evaluated in 36 patients with recurrent and/or metastatic (R/M) HNSCC. The primary end point was objective response rate after two cycles of treatment. Secondary end points include the safety and tolerability profile and overall survival. Correlative studies with exome mutational analysis were performed in pre-treatment biopsy samples from 21 patients.

Results

Fifteen (41.7%) patients had an objective response, which were all partial responses, and 19 (52.3%) patients had stable disease as best response. The two patients who were designated as 'non-responders' were removed from study prior to two cycles of treatment, but are included in the efficacy and safety analyses. The median duration on study was 5.3 months and the median progression-free survival and overall survival were 5.9 months (95% confidence interval, 4.8-7.1) and 12.8 months (95% confidence interval, 9.8-15.8), respectively. The most common grade 3 and 4 adverse events were hematologic toxicities. Three (3.8%) patients developed neutropenic fever on study. Three of four patients with PIK3CA mutations experienced tumor regressions, and responses were also seen in patients with other genetic alterations in the PI3K/mTOR pathway.

Conclusion

The combination of temsirolimus with low-dose weekly carboplatin and paclitaxel appears to have meaningful clinical efficacy in the treatment of R/M HNSCC. This regimen has a relatively high response rate compared to other treatments evaluated in R/M HNSCC, and potential associations with genetic alterations in the PI3K/mTOR pathway should be further explored.

A phase II study of axitinib (AG-013736) in patients with incurable adenoid cystic carcinoma

BACKGROUND

Recurrent/metastatic adenoid cystic carcinoma (ACC) is an incurable disease with no standard treatments. The majority of ACCs express the oncogenic transcription factor MYB (also c-myb), often in the context of a MYB gene rearrangement. This phase II trial of the tyrosine kinase inhibitor (TKI) axitinib (Pfizer) tested the hypothesis that targeting pathways activated by MYB can be therapeutically effective for ACC.

PATIENTS AND METHODS

This is a minimax two-stage, phase II trial that enrolled patients with incurable ACC of any primary site. Progressive or symptomatic disease was required. Patients were treated with axitinib 5 mg oral twice daily; dose escalation was allowed. The primary end point was best overall response (BOR). An exploratory analysis correlating biomarkers to drug benefit was conducted, including next-generation sequencing (NGS) in 11 patients.

RESULTS

Thirty-three patients were registered and evaluable for response. Fifteen patients had the axitinib dose increased. Tumor shrinkage was achieved in 22 (66.7%); 3 (9.1%) had confirmed partial responses. Twenty-five (75.8%) patients had stable disease, 10 of whom had disease stability for >6 months. The median progression-free survival (PFS) was 5.7 months (range 0.92-21.8 months). Grade 3 axitinib-related toxicities included hypertension, oral pain and fatigue. A trend toward superior PFS was noted with the MYB/NFIB rearrangement, although this was not statistically significant. NGS revealed three tumors with 4q12 amplification, producing increased copies of axitinib-targeted genes PDGFR/KDR/KIT. Two 4q12 amplified patients achieved stable disease for >6 months, including one with significant tumor reduction and the longest PFS on study (21.8 months).

CONCLUSIONS

Although the primary end point was not met, axitinib exhibited clinical activity with tumor shrinkage achieved in the majority of patients with progressive disease before trial enrollment. Analysis of MYB biomarkers and genomic profiling suggests the hypothesis that 4q12 amplified ACCs are a disease subset that benefit from TKI therapy.

Phase I study of weekly nab-paclitaxel + weekly cetuximab + intensity-modulated radiation therapy (IMRT) in patients with stage III-IVB head and neck squamous cell carcinoma (HNSCC)

BACKGROUND

There is a clinical need to improve the efficacy of standard cetuximab + concurrent intensity-modulated radiation therapy (IMRT) for patients with locally and/or regionally advanced HNSCC. Taxanes have radiosensitizing activity against HNSCC, and nab-paclitaxel may offer therapeutic advantage in comparison with other taxanes.

PATIENTS AND METHODS

This was a single-institution phase I study with a modified 3 + 3 design. Four dose levels (DLs) of weekly nab-paclitaxel were explored (30, 45, 60, and 80 mg/m(2)), given with standard weekly cetuximab (450 mg/m(2) loading dose followed by 250 mg/m(2) weekly) and concurrent IMRT (total dose, 70 Gy).

RESULTS

Twenty-five eligible patients (20 M, 5 F) enrolled, with median age 58 years (range, 46-84 years). Primary tumor sites were oropharynx, 19 (10 human papillomavirus [HPV] pos, 8 HPV neg, 1 not done); neck node with unknown primary, 2; larynx 2; and oral cavity and maxillary sinus, 1 each. Seven patients had received prior induction chemotherapy. Maximum tolerated dose (MTD) was exceeded at DL4 (nab-paclitaxel, 80 mg/m(2)) with three dose-limiting toxicities (DLTs) (grade 3 neuropathy, grade 3 dehydration, with grade 3 mucositis grade 3 anemia) among five assessable patients. There was only one DLT (grade 3 supraventricular tachycardia) among six patients at DL3 (nab-paclitaxel, 60 mg/m(2)), and this was deemed the MTD. Among 23 assessable patients, the most common ≥ g3 AEs were lymphopenia 100%, functional mucositis 65%, and pain in throat/oral cavity 52%. At a median follow-up of 33 months, 2-year failure-free survival (FFS) is 65% [95% confidence interval (CI) 42% to 81%] and 2-year overall survival (OS) is 91% (95% CI 69-97).

CONCLUSION

The recommended phase II dose for nab-paclitaxel is 60 mg/m(2) weekly when given standard weekly cetuximab and concurrent IMRT. This regimen merits further study as a nonplatinum alternative to IMRT + cetuximab alone.

CLINICALTRIALSGOV ID

NCT00736619.

Phase II study of depsipeptide (DEP) in radioiodine (RAI)-refractory metastatic nonmedullary thyroid carcinoma

6059

Background: Historically, systemic therapy for radioactive iodine (RAI)-refractory thyroid cancer has been understudied. Available drugs have modest efficacy. Depsipeptide (DEP) is a histone deacetylase inhibitor with potent anti-tumor effects both in vitro and in vivo. In thyroid cancer cell lines, DEP increases expression of both thyroglobulin and the sodium/iodine symporter messenger RNAs, offering the possibility of improved iodine concentrating ability of radioactive iodine (RAI)-resistant tumors. Methods: Eligible patients (pts) must have progressive, RAI-refractory, recurrent/metastatic, non-medullary, non-anaplastic thyroid cancer; RECIST measurable disease; and adequate organ/marrow function. Exclusionary criteria include prior chemotherapy in the recurrent/metastatic setting; cardiac disease or dysfunction; QTc prolongation or co-administration of drugs that prolong the QTc. DEP 13 mg/m2 IV is administered on days 1, 8, 15, every 28 days. The primary endpoint is response rate by RECIST criteria; change in RAI avidity is a secondary endpoint. The study closed early due to poor accrual after an unexpected grade 5 adverse event (AE) that prompted protocol suspension. Results: 20 pts were enrolled: female-50%; median age-64 years; histology-papillary (8)/follicular (1)/Hürthle (11). Grade 4–5 AE possibly related to drug: grade 5 sudden death (1); grade 4 -pulmonary embolus (1). Twelve of 20 subjects had a reported AE. No RECIST major responses have been seen. Evaluation of response: stable disease (10); progression (3); early death (1); unknown/inevaluable (6: 5 - temporary protocol suspension; 1 - withdrew consent). Restoration of RAI avidity was documented in 2 pts. For evaluable patients (14) only, median overall survival and time on study was 36 (.5–45+) months and 1.7 (0.46–12) months, respectively. Conclusions: We observed preliminary signs of in vivo reversal of RAI resistance after treatment with DEP. However, no major responses were observed and accrual was poor after the grade 5 AE. (Study funded by grant N01 CM 62206)

No significant financial relationships to disclose.

Phase II study of bevacizumab (B) plus cisplatin (C) plus intensity-modulated radiation therapy (IMRT) for locoregionally advanced head and neck squamous cell cancer (HNSCC): Preliminary results

6013

Background: For patients with locoregionally advanced HNSCC, concurrent high-dose cisplatin + radiation therapy is a historical standard of care. HNSCC tumors expressing high levels of VEGF have been associated with worse prognosis, and bevacizumab may sensitize tumors to cisplatin and radiation. Methods: Percutaneous gastrostomy (PEG) tube was placed pre-treatment for all patients. Planned treatment consisted of definitive IMRT (total, 70 Gy) with concurrent C (50 mg/m2 days 1, 2, 22, 23, 43, 44) and B (15 mg/kg days 1, 15, and 43). The initial version of the protocol called for an additional 6 months of maintenance B, but this was discontinued in an amendment after a G4 pulmonary hemorrhage event in subject 1 during maintenance treatment. 1o endpoint was 2-year PFS. Results: 42 previously untreated patients (34 M, 8 F), median age 55 (27–75), with stage III/IV, M0 HNSCC (oropharynx 39, larynx 3) enrolled. HPV status by ISH: 16 pos, 14 neg, 12 unknown). All patients have completed treatment. CTCAE v3.0 toxicities (% patients) have included: functional mucositis G3 (76 %); nausea G3 (24%); vomiting G3 (17%); neutropenia G3 (31%), G4 (10%); hemoglobin G3 (17%); hyponatremia G3 (14%). Median weight loss during treatment was 8.9 kg (2.1–26 kg). There were two deaths within 90 days of last treatment: 1 aspiration pneumonia, 1 sudden death. Median follow up is approximately 9 months (range, <3 to 24 months). Locoregional control rate is 100%. Three patients have developed distant metastasis. Estimated one-year PFS is 83% (± 10%) and estimated 1 year OS is 88% (± 6%). At a median of 8 months after completion of radiation therapy, PSS-HN scores were 100 for eating, speech, and diet in respectively 88%, 76%, and 53% of surveyed patients (n = 17). Conclusions: The addition of B to C + IMRT did not appear to increase toxicity to unacceptable levels, and preliminary efficacy results are encouraging.

[Table: see text]

Phase I study of everolimus (E; RAD001) + low-dose weekly cisplatin (C) for patients with advanced solid tumors: Preliminary results

e14527

Background: Preclinical studies demonstrate synergistic anti-tumor activity with the combination of E + C. Methods: Patients received E per oral for days 1–21 of a 28 day cycle. E was dose escalated though 4 planned dose levels (DLs): 2.5 mg/day, 5 mg/day, 7.5 mg/day, and 10 mg/day. Cisplatin dose was fixed at 20 mg/m2 intravenously on days 1, 8, 15. A standard 3 + 3 dose escalation scheme was used. Blood samples for pharmacokinetics were collected on Day 1 and Day 8 of Cycle 1. Response was assessed by RECIST after 2 cycles. Results: 24 patients enrolled: 13 M, 11F; median age 62 (32–77); median number of prior cytotoxic chemotherapy regimens 1 (0–3; 75% with prior RT). At DL1, 3 patients were inevaluable (1 withdrawal of consent prior to treatment, 1 disease progression during cycle 1, 1 recurrent diverticulitis during cycle 1) and were replaced. DL 1 was expanded after a patient with melanoma metastatic to liver had sudden death of unclear cause, and the protocol was amended to exclude patients with hepatic dysfunction. At DL2, one patient experienced grade 3 small bowel obstruction of uncertain etiology, and the dose level was expanded to 6 evaluable patients without additional DLT. No DLTs occurred at DL3. No DLTs have occurred to date among 6 patients enrolled at DL 4. Adverse events per cycle (total n = 63 cycles; 20 patients evaluable for toxicity) include: lymphopenia G3 (19%), AST G3 (3.2%), alkaline phosphatase G3 (3.2%), ALT G3 (1.6%), hyponatremia (1.6%). Median cycles per patient, 2 (range <1 to 10+). Minor response seen in pulmonary carcinoid (n = 1); prolonged SD ≥ 6 cycles seen in pulmonary carcinoid (n=2), basal cell carcinoma (n=1), and esthesioneuroblastoma (n=1). Conclusions: Pending safety analysis at the final planned dose level, the phase II recommended dose is E 10 mg/day (days 1 - 21) + C 20 mg/m2 (days 1, 8, and 15) on a 28-day cycle.

[Table: see text]

Doxorubicin and concurrent radiotherapy for anaplastic thyroid cancer: We need to do better

16506

Background: Anaplastic thyroid cancer (ATC) is a rare, aggressive malignancy. The potential for pathologic misclassification complicates the interpretation of published data. One treatment option for locoregionally (LR) advanced disease is weekly low-dose doxorubicin (D) with concurrent radiation therapy (RT), based on reported 2-year local control rates of 68% (ATC)/77% (other TC histologic subtypes) (Cancer 1987;60:2372). We looked to evaluate our experience with this general approach, but in a larger series which included pathologic confirmation of all ATC cases. Methods: Patients (pts) were identified through the Memorial Sloan-Kettering Cancer Center (MSKCC) Radiation Oncology and Pathology Databases. Inclusion criteria: diagnosis of ATC between 1984–2006, with pathology review at MSKCC; LR disease only, able to be encompassed within a RT portal; treatment at MSKCC with planned weekly D (10 mg/m2) and concurrent radiation. Prior surgery was allowed. Documentation of failure was based on clinical/radiographic assessment. Principal outcomes assessed: LR control (LRC: no failure at the primary site, in the neck, or the mediastinum), progression-free survival (PFS), and overall survival (OS). The Kaplan-Meier method was applied. Results: Thirty-seven patients were included in our analysis (median age 64; 54% female, 46% male). Median RT dose 5760 cGy, >4500 cGy in 32 (87%), administered through hyperfractionated or once-daily schedules. Median number of D treatments received 5.5, >4 in 24 (65%). 2-year outcomes: LRC 25%; PFS 8%; OS 18%. 6 patients remain alive at the time of last follow-up with survival durations of 4.1, 11.4, 11.7, 57.3, 58.5, and 140.7 months, respectively. A subset analysis was performed limited to the 24 patients (65%) who completed >4,500 cGy of radiation and >4 doses of D. 2-year outcomes were improved in this latter group, but remained disappointing, even among these more highly selected pts (LRC 30%; PFS 11%; OS 27%). Conclusions: Better therapy is needed for this poor prognostic disease. Future analyses will evaluate the impact of histologic subtype of ATC, radiation technique/dose, and surgical resection on outcome.

No significant financial relationships to disclose.

Phase I study of pemetrexed (P) plus gemcitabine (G) in advanced solid tumors (ST)

14055

Background: P is active in multiple ST types, and preclinical data support P synergy with G. Methods: Eligible advanced ST patients (pts) with no prior P or G, no prior radiotherapy (RT) to ≡ 25% of the marrow, Karnofsky Performance Status ≡ 70%, and adequate organ function enrolled in cohorts (C) of 3, expanding to 6 if dose-limiting toxicity (DLT) occurred. P was given at 300 (C1), 400 (C2), 500 (C3) or 600 (C4) mg/m2 followed by G at 1500 mg/m2 q 14 days (d) without granulocyte-colony stimulating factor. Vitamin B12 and folate supplementation were given. Response was assessed by RECIST Results: 29 pts (median number prior regimens 2, range 1–5; 66% with prior RT) enrolled and are evaluable for safety; 23 are evaluable for response. There were no DLTs in C1. One pt in C2 was replaced after 1 cycle for progression of disease (PD). Among the next 6 pts, 2 had DLTs (1 G3 thrombocytopenia [TP] treatment delay; 1 neutropenic fever [NF]). C2-R (C2, Revised) re-opened after amendment permitting ≡ 2 prior cytotoxic regimens, no history of brain metastases/brain RT. C2-R enrolled 8 pts with 1 DLT (G3 TP with treatment delay) and 2 pts replaced (1 early PD, 1 no documented duration of neutropenia [NP]). C3 had 0/3 pts with DLT. C4 had 2/3 pts with DLTs (1 G4 hyponatremia; 1 herpes zoster-related treatment delay). C3 has been expanded to 5 of 6 planned patients, one with DLT (NF, G4 TP). Toxicities per cycle (n= 189 cycles, 29 patients): include NP-G3 (23%), G4 (14%); TP-G3 (2%); WBC-G3 (30%), G4 (4%); lymphopenia-G3 (11%), Hgb-G3 (4%); G3-NF (1%). 3/23 (13%) had objective partial responses (2 head and neck squamous cell cancer, HNSCC; 1 nasopharyngeal cancer, NPC), 4 stable disease (SD), 16 PD. (1 pt, no measurable disease at baseline; 5 pts, too early for response assesment). Conclusions: G + P is well-tolerated, and yields objective responses in HNSCC and NPC. C3 (P 500 mg/m2 + G 1500 mg/m2 q 14 d) was the phase II recommended dose in another phase I study of this regimen (Melemed ASCO 2005). Our final results will be available for ASCO 2007.

No significant financial relationships to disclose.

Multiple protein: protein interactions between the snRNP common core proteins

The snRNP core proteins (B, D3, D2, D1, E, F, and G) assemble with snRNA and form the snRNP core particle with a suggested stoichiometry of B2[D1, D2(E, F, G)2]D3. The newly synthesized snRNP core proteins are stored in the cytoplasm in three RNA-free complexes of (1) B at 2S-6S; (2) [D1, D2(E, F, G)2] at 6S; and (3) (B, D3, and 69 kDa) at 20S. The snRNP proteins assemble stepwise with snRNAs that appear transiently in the cytoplasm before returning to the nucleus as mature snRNP particles. In this report, two approaches are used to investigate the protein:protein interactions between the snRNP proteins. First, the 6S and 20S cytoplasmic complexes chromatographed as intact structures, supporting their identifications as discrete complexes. Second, the cDNAs for the proteins were used to test all pair-wise interactions between the seven major core proteins using the yeast two-hybrid system. The two-hybrid system identified four strong reciprocal interactions, one weak reciprocal interaction, five one-way interactions, and one homotypic interaction. The strongest interactions were between proteins within the 6S particle. Other interactions were between proteins in the 6S and 20S particles or within the 20S particle itself. These interactions are likely to occur within the cytoplasmic snRNP core protein complexes and the mature snRNP particle.

In vitro interaction of U2 snRNA with cytoplasmic 6S protein complexes

Interactions of U2 snRNA with anti-Sm precipitable proteins in RNA-free cytoplasmic complexes were analyzed. U2 snRNA was found to bind specifically with proteins in the 6S complexes but not in the 20S complexes. The binding activity was preserved using U2 snRNA having a mutated Sm binding site. Label-transfer experiments indicate that snRNA makes direct contact with anti-Sm precipitable proteins in the 6S fraction with apparent molecular mass of about 16 kDa. These data corroborate that proteins in the 6S core particle are the first to interact with snRNA, and suggest that the proteins recognize snRNA structures in addition to the Sm site.

U6 snRNA maturation and stability

The U6 snRNP is found as a monomer and as a heterodimer, complexed with the U4 snRNP (U4/U6). Northern blotting detects approximately equal amounts of U4/U6 heterodimer and U6 monomer in the nucleus but only U6 monomer in bona fide cytoplasm. In mammalian cells, newly synthesized U6 appears transiently in the cytoplasm before returning to the nucleus. Sedimentation analysis identifies cytoplasmic U6 in similarly sized structures as nuclear U4 and U6 and smaller structures than cytoplasmic U4. Inhibitor studies demonstrate that newly synthesized U6 can move from the cytoplasm into the nucleus in the absence of U4 synthesis. The nuclear half-life of U6 is significantly shorter than that of U4 and the other spliceosomal snRNAs. These data support a model in which U4 and U6 snRNAs undergo distinct cytoplasmic maturation pathways before returning to the nucleus, where the U4/U6 snRNP assembles.