IELSG38: phase II trial of front-line chlorambucil plus subcutaneous rituximab induction and maintenance in mucosa-associated lymphoid tissue lymphoma.

The IELSG38 trial was conducted to investigate the effects of subcutaneous (SC) rituximab on the complete remission (CR) rate and the benefits of SC maintenance in patients with extranodal marginal zone lymphoma (MZL) who received frontline treatment with chlorambucil plus rituximab. Study treatment comprised an induction phase with chlorambucil 6 mg/m2/day orally on weeks 1-6, 9-10, 13-14, 17-18, and 21-22, and rituximab 375 mg/m2 intravenously on day 1 of weeks 1-4, and 1400 mg SC on weeks 9, 13, 17, and 21. Then, a maintenance phase followed with rituximab administered at 1400 mg SC every two months for two years. Of the 112 patients enrolled, 109 were evaluated for efficacy. The CR rates increased from 52% at the end of the induction phase to 70% upon completion of the maintenance phase. With a median follow-up of 5.8 years, the 5-year event-free, progression-free, and overall survival rates were 87% (95% CI, 78-92), 84% (95% CI, 75-89), and 93% (95% CI, 86-96), respectively. The most common grade ≥3 toxicities were neutropenia (33%) and lymphocytopenia (16%). Six patients experienced treatment-related serious adverse events, including fever of unknown origin, sepsis, pneumonia, respiratory failure, severe cerebellar ataxia, and fatal acute myeloid leukemia. The trial showed that subcutaneous rituximab did not improve the complete remission rate at the conclusion of the induction phase, which was the main endpoint. Nevertheless, SC maintenance might have facilitated long-term disease control, potentially contributing to enhanced event-free and progression-free survival.

Long-term results of the MCL01 phase II trial of rituximab plus HyperCVAD alternating with high-dose cytarabine and methotrexate for the initial treatment of patients with mantle cell lymphoma.

Mantle cell lymphoma is a rare and incurable lymphoproliferative disorder. In the MCL01 trial, patients were treated with the R-HCVAD regimen [rituximab plus HyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone; R-CVAD) alternating with high-dose methotrexate and cytarabine (AM)] for four cycles followed by autologous stem cell transplantation (ASCT) for those who reached only a partial response. After a median follow-up of 10·5 years, we reported 10-year progression-free and overall survival rates of 35% and 61% respectively, with a 10-years cumulative incidence rate of second malignancies of 10·6%. Mature results of the MCL01 trial confirmed the efficacy of HyperCVAD-AM as a frontline regimen for younger patients (≤65 years).

Atypical Presentation of COVID-19 Incidentally Detected at 18F-FDG PET/CT in an Asymptomatic Oncological Patient.

The incidence of COVID-19, a severe acute respiratory syndrome caused by SARS-CoV-2, is rapidly growing worldwide. In this pandemic period, the chance of incidental pulmonary findings suggestive of COVID-19 at F-FDG PET/CT in asymptomatic oncological patients is not negligible. To suspect COVID-19 is more demanding whether its presentation is atypical. We describe the incidental PET/CT detection of an F-FDG-avid isolated centrilobular pulmonary consolidation in an asymptomatic lymphoma patient, which later resulted in an unexpected and atypical COVID-19 presentation. The nuclear medicine physicians should be prepared to suspect COVID-19 even in asymptomatic patients presenting with a "far-from-COVID-19" finding at PET/CT.

Nonpeghylated liposomal doxorubicin combination regimen (R-COMP) for the treatment of lymphoma patients with advanced age or cardiac comorbidity.

Doxorubicin is the most effective single agent in the treatment of non-Hodgkin's lymphoma (NHL). Its use is limited because of the cardiac toxicity primarily in elderly patients (pts) and in pts with history of cardiac disease. Liposomal doxorubicin has been proven to reduce cardiotoxicity. The aim of this retrospective study was the use of nonpeghylated liposomal doxorubicin (NPLD) in term of efficacy, response rate and incidence of cardiac events. We retrospectively collected the experience of 33 Hematological Italian Centers in using NPLD. Nine hundred and forty-six consecutive pts treated with R-COMP (doxorubicin was substituted with NPLD, Myocet) were collected. Median age was 74 years, the reasons for use of NPLD were: age (466 pts), cardiac disease (298 pts), uncontrolled hypertension (126 pts), other reasons (56 pts). According to clinicians' evaluation, 49.9% of pts would not have used standard doxorubicin for different situations (age, cardiomyopathy, previous use of doxorubicin, and uncontrolled hypertension). Overall 687 pts (72.6%) obtained a complete remission (CR). About 5% (n = 51) of subjects developed major cardiotoxic events including heart failure (N = 31), ischemic heart disease (N = 16), acute heart attack (N = 3), and acute pulmonary oedema (N = 1). After a median follow-up of 32 months, 651 pts were alive and the overall survival (OS) was 72%. After a median observation period of 23 months disease free survival (DFS) was 58%. Either in univariate or in multivariate analysis OS and DFS were not significantly affected by age or cardiac disease. Our findings strongly support that including R-COMP is effective and safe when the population is at high risk of cardiac events and negatively selected. Moreover, the use of this NPLD permitted that about half of our population had the opportunity to receive the best available treatment.

Prolonged survival in the absence of disease-recurrence in advanced-stage follicular lymphoma following chemo-immunotherapy: 13-year update of the prospective, multicenter randomized GITMO-IIL trial.

A prospective trial conducted in the period 2000-2005 showed no survival advantage for high-dose chemotherapy with rituximab and autograft (R-HDS) versus conventional chemotherapy with rituximab (CHOP-R) as first-line therapy in 134 high-risk follicular lymphoma patients aged <60 years. The study has been updated at the 13-year median follow up. As of February 2017, 88 (66%) patients were alive, with overall survival of 66.4% at 13 years, without a significant difference between R-HDS (64.5%) and CHOP-R (68.5%). To date, 46 patients have died, mainly because of disease progression (47.8% of all deaths), secondary malignancies (3 solid tumor, 9 myelodysplasia/acute leukemia; 26.1% of all deaths), and other toxicities (21.7% of all deaths). Complete remission was documented in 98 (73.1%) patients and associated with overall survival, with 13-year estimates of 77.0% and 36.8% for complete remission versus no-complete remission, respectively. Molecular remission was documented in 39 (65%) out of 60 evaluable patients and associated with improved survival. In multivariate analysis, complete remission achievement had the strongest effect on survival (P<0.001), along with younger age (P=0.002) and female sex (P=0.013). Overall, 50 patients (37.3%) survived with no disease recurrence (18 CHOP-R, 32 R-HDS). This follow up is the longest reported on follicular lymphoma treated upfront with rituximab-chemotherapy and demonstrates an unprecedented improvement in survival compared to the pre-rituximab era, regardless of the use of intensified or conventional treatment. Complete remission was the most important factor for prolonged survival and a high proportion of patients had prolonged survival in their first remission, raising the issue of curability in follicular lymphoma. (Registered at clinicaltrials.gov identifier: 00435955).

Combination of rituximab and nonpegylated liposomal doxorubicin (R-NPLD) as front-line therapy for aggressive non-Hodgkin lymphoma (NHL) in patients 80 years of age or older: a single-center retrospective study.

The incidence of non-Hodgkin lymphoma in patients 80 years of age or older is 50 times higher than in 20- to 24-year-olds. Very elderly patients are often not treated with standard immunochemotherapy because of poor performance status, comorbidities, and toxicity concerns. We retrospectively analyzed data for 29 patients diagnosed with diffuse large B-cell lymphoma or grade 3B follicular lymphoma and treated with rituximab in combination with nonpegylated liposomal doxorubicin between January 2010 and August 2015. The median age was 84 years. The overall 3-year survival, cause-specific survival, and progression-free survival rates were 46%, 55%, and 44%, respectively. Among prognostic factors, only the achievement of complete remission strongly correlated with overall survival, cause-specific survival, and progression-free survival rates. Treatment caused very mild toxicity, without treatment-related hospitalization or toxic deaths.

Long-Term Results of the FOLL05 Trial Comparing R-CVP Versus R-CHOP Versus R-FM for the Initial Treatment of Patients With Advanced-Stage Symptomatic Follicular Lymphoma.

Purpose The FOLL05 trial compared R-CVP (rituximab plus cyclophosphamide, vincristine, and prednisone) with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) and R-FM (rituximab plus fludarabine and mitoxantrone) regimens without rituximab maintenance as initial therapy for patients with advanced-stage follicular lymphoma (FL). A previous analysis with a median follow-up of 34 months showed a superior 3-year time to treatment failure, the primary study end point, with R-CHOP and R-FM versus R-CVP and showed R-CHOP to have a better risk-benefit ratio in terms of toxicity than R-FM. We report a post hoc analysis of this trial after a median follow-up of 7 years. Patients and Methods Of the 534 enrolled patients, 504 were evaluable. At the time of analysis, the median follow-up was 84 months (range, 1 to 119 months). Results The 8-year time to treatment failure and progression-free survival rates were 44% (95% CI, 39% to 49%) and 48% (95% CI, 43% to 53%), respectively. The hazard ratio for progression-free survival adjusted by FL International Prognostic Index 2 versus R-CVP was 0.73 for R-CHOP (95% CI, 0.54 to 0.98; P = .037) and 0.67 for R-FM (95% CI, 0.50 to 0.91; P = .009). The 8-year overall survival (OS) rate was 83% (95% CI, 79% to 87%), with no significant differences among study arms. Overall, we observed a higher risk of dying as a result of causes unrelated to lymphoma progression with R-FM versus R-CVP. Conclusion With an 83% 8-year OS rate, long-term follow-up of the FOLL05 trial confirms the favorable outcome of patients with advanced-stage FL treated with immunochemotherapy. The three study arms had similar OS but different activity and toxicity profiles. Patients initially treated with R-CVP had a higher risk of lymphoma progression compared with those receiving R-CHOP, as well as a higher risk of requiring additional therapy.

Whole-brain radiotherapy or autologous stem-cell transplantation as consolidation strategies after high-dose methotrexate-based chemoimmunotherapy in patients with primary CNS lymphoma: results of the second randomisation of the International Extranodal Lymphoma Study Group-32 phase 2 trial.

BACKGROUND: The International Extranodal Lymphoma Study Group-32 (IELSG32) trial is an international randomised phase 2 study that addresses two key clinical questions in the treatment of patients with newly diagnosed primary CNS lymphoma. Results of the first randomisation have demonstrated that methotrexate, cytarabine, thiotepa, and rituximab (called the MATRix regimen) is the induction combination associated with significantly better outcome compared with the other induction combinations tested. Here, we report the results of the second randomisation that addresses the efficacy of myeloablative chemotherapy supported by autologous stem-cell transplantation (ASCT), as an alternative to whole-brain radiotherapy (WBRT), as consolidation after high-dose-methotrexate-based chemoimmunotherapy. METHODS: HIV-negative patients (aged 18-70 years) with newly diagnosed primary CNS lymphoma and an Eastern Cooperative Oncology Group performance status of 0-3 were randomly assigned to receive four courses of methotrexate 3·5 g/m2 on day 1 plus cytarabine 2 g/m2 twice daily on days 2 and 3 (group A); or the same combination plus two doses of rituximab 375 mg/m2 on days -5 and 0 (group B); or the same methotrexate-cytarabine-rituximab combination plus thiotepa 30 mg/m2 on day 4 (group C), with the three groups repeating treatment every 3 weeks. Patients with responsive or stable disease after induction treatment, with adequate autologous peripheral blood stem-cell collection, and without persistent iatrogenic side-effects, were eligible for the second randomisation between WBRT (photons of 4-10 MeV; five fractions per week; fraction size 180 cGy; started within 4 weeks from the last induction course; group D) and carmustine-thiotepa conditioned ASCT (carmustine 400 mg/m2 on day -6, and thiotepa 5 mg/kg every 12 h on days -5 and -4, followed by reinfusion of autologous peripheral blood stem cells; group E). A permuted block randomised design was adopted for both randomisations, and a computer-generated randomisation list was used within each stratum. No masking after assignment to intervention was adopted. The primary endpoint was 2-year progression-free survival, with induction group and response to induction chemotherapy as stratification parameters. Analyses were done on a modified intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT01011920. FINDINGS: Between Feb 19, 2010, and Aug 27, 2014, 227 patients were recruited from 53 centres in five countries. 219 of 227 enrolled patients were assessable. Of the 122 patients eligible for the second randomisation, 118 patients were randomly assigned to WBRT or ASCT (59 patients per group) and constitute the study population. WBRT and ASCT were both effective, and achieved the predetermined efficacy threshold of at least 40 progression-free survivors at 2 years among the first 52 patients in both groups D and E. There were no significant differences in 2-year progression-free survival between WBRT and ASCT: 80% (95% CI 70-90) in group D and 69% (59-79) in group E (hazard ratio 1·50, 95% CI 0·83-2·71; p=0·17). Both consolidation therapies were well tolerated. Grade 4 non-haematological toxicity was uncommon; as expected, haematological toxicity was more common in patients treated with ASCT than in those who received WBRT. Two toxic deaths (infections) were recorded, both in patients who received ASCT. INTERPRETATION: WBRT and ASCT are both feasible and effective as consolidation therapies after high-dose methotrexate-based chemoimmunotherapy in patients aged 70 years or younger with primary CNS lymphoma. The risks and implications of cognitive impairment after WBRT should be considered at the time of therapeutic decision. FUNDING: Agenzia Italiana del Farmaco, Cancer Research UK, Oncosuisse, and Swiss National Science Foundation.

A Multicenter Phase II Study of Twice-Weekly Bortezomib plus Rituximab in Patients with Relapsed Follicular Lymphoma: Long-Term Follow-Up.

Single-agent bortezomib (B) has shown activity in heavily pretreated patients with relapsed/refractory indolent lymphoma. On the basis of these findings, we performed a phase II study of B combined with rituximab (R) in patients with relapsed follicular lymphoma (FL). Forty-five patients with fairly good prognostic profiles were enrolled from 2007 to 2011 and received a total of 6 cycles of the B+R combination. The endpoints were the overall response rate (ORR), progression-free survival (PFS), duration of remission (DoR), overall survival (OS), and toxicity evaluation. When considering all the enrolled patients the ORR was 64%. At 5 years, the estimated PFS, DoR, and OS were 34, 49, and 70%, respectively. After excluding the 7 R-naïve patients, the ORR was 58%, with a PFS of 19 months. The most common grade >2 toxicities were thrombocytopenia (18%), peripheral neuropathy (13%), and neutropenia (2%). Our study shows the feasibility, long-term efficacy, and excellent tolerability of the B+R combination. We are aware that our study has specific limitations, such as the small sample size consisting of patients with a relatively good prognostic profile. However, because FL patients will be treated with subsequent chemotherapy regimens, a well-tolerated and effective chemotherapy-free therapy could be considered an additional tool for long-term disease control.

The chronic lymphocytic leukemia international prognostic index predicts time to first treatment in early CLL: Independent validation in a prospective cohort of early stage patients.

The chronic lymphocytic leukemia International Prognostic Index (CLL-IPI) combines 5 parameters (age, clinical stage, TP53 status [normal vs. del(17p) and/or TP53 mutation], IGHV mutational status, serum ß2-microglobulin) to predict survival and time-to-first-treatment (TTFT) in CLL patients. We performed an observational study in 337 prospectively collected, Binet stage A patients to validate the ability of the CLL-IPI to predict TTFT in an independent cohort of early stage CLL patients. The CLL-IPI score stratified Binet stage A patients into three subgroups with different outcome. Since the CLL-IPI was originally developed to predict survival, we next investigated the optimal cut-off score to predict TTFT in Binet stage A patients. Recursive partitioning analysis identified three subsets with scores of 0 (n = 139), 1 (n = 90), and ≥ 2(n = 108). The probability of remaining free from therapy 5 years after diagnosis was 85%, 67% and 46% in these three categories (P < 0.0001.; C-statistic:c = 0.72; 95% CI:0.58-0.81). This optimized CLL-IPI scoring for TTFT was subsequently validated in an independent cohort of Binet A patients from the Mayo Clinic (n = 525). The ability of either original or optimized CLL-IPI to predict TTFT was equivalent to other prognostic models specifically designed for this endpoint (2011 MDACC score and O-CLL1 score). Although originally developed to predict suvival, the CLL-IPI is useful for predicting TTFT in early stage CLL patients. Am. J. Hematol. 91:1090-1095, 2016. © 2016 Wiley Periodicals, Inc.

Combination of bendamustine and rituximab as front-line therapy for patients with chronic lymphocytic leukaemia: multicenter, retrospective clinical practice experience with 279 cases outside of controlled clinical trials.

Recently, encouraging results in terms of safety and efficacy have been obtained using bendamustine-rituximab (BR) in untreated chronic lymphocytic leukaemia (CLL) patients enrolled in a phase II study. Here, we report a retrospective international multicenter study of CLL patients treated with BR as front-line therapy. The cohort included 279 patients with progressive CLL from 33 centers (29 Italian, 3 Israeli and 1 German) who received at least 1 cycle of BR as first-line treatment during the 2008-2014 period. The primary objective of this study was to evaluate the efficacy and safety of BR administered as front-line therapy, outside of controlled clinical trials. Median age was 70 years (range, 43-86 years); 62.4% were males and 35.8% had Binet stage C. Forty-two patients (15.2%) were unfit (cumulative illness rating scale [CIRS] score ≥7), and 140 (50.2%) had creatinine clearance ≤70 ml/min. Fluorescent in situ hybridisation analysis, available for 192 cases, showed that 21 (10.9%) had del11q and 18 (9.4%) del17p. The overall response rate (ORR) was 86.4%, with a complete remission rate of 28%. Patients with del17p had an ORR of 66.7%. After median follow-up of 24 months, the 2-year progression-free survival (PFS) was 69.9%; CIRS ≥7, immunoglobulin heavy-chain variable-region (IGHV) unmutated status, del17p and BR dose intensity <80% were independently associated with shorter PFS. Grade III or IV neutropenia, thrombocytopenia, and anaemia were observed in 25.9%, 15.4%, and 15.1% of patients, respectively. Twenty-four patients (8.6%) had severe infections. BR is also an effective and safe regimen for untreated CLL patients, outside of controlled clinical trials.

Long-Term Results of the HD2000 Trial Comparing ABVD Versus BEACOPP Versus COPP-EBV-CAD in Untreated Patients With Advanced Hodgkin Lymphoma: A Study by Fondazione Italiana Linfomi.

PURPOSE: The randomized HD2000 trial compared six cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine), four escalated plus two standard cycles of BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone), and six cycles of COPP-EBV-CAD (cyclophosphamide, lomustine, vindesine, melphalan, prednisone, epidoxorubicin, vincristine, procarbazine, vinblastine, and bleomycin; CEC) in patients with advanced-stage Hodgkin lymphoma. After a median follow-up of 42 months, patients who received BEACOPP were reported to have experienced better progression-free survival (PFS) but not better overall survival (OS) results than those receiving ABVD. We here report a post hoc analysis of this trial after a median follow-up of 10 years. PATIENTS AND METHODS: Three hundred seven patients were enrolled, 295 of whom were evaluable. At the time of our analysis, the median follow-up for the entire group was 120 months (range, 4 to 169 months). RESULTS: The 10-year PFS results for the ABVD, BEACOPP, and CEC arms were 69%, 75%, and 76%, respectively; corresponding OS results were 85%, 84%, and 86%. Overall, 13 second malignancies were reported: one in the ABVD arm and six each in the BEACOPP and CEC arms. The cumulative risk of developing second malignancies at 10 years was 0.9%, 6.6%, and 6% with ABVD, BEACOPP, and CEC, respectively; the risk with either BEACOPP or CEC was significantly higher than that reported with ABVD (P = .027 and .02, respectively). CONCLUSION: With these mature results, we confirm that patients with advanced Hodgkin lymphoma have similar OS results when treated with ABVD, BEACOPP, or CEC. However, with longer follow-up, we were not able to confirm the superiority of BEACOPP over ABVD in terms of PFS, mainly because of higher mortality rates resulting from second malignancies observed after treatment with BEACOPP and CEC.

Prospective validation of predictive value of abdominal computed tomography scan on time to first treatment in Rai 0 chronic lymphocytic leukemia patients: results of the multicenter O-CLL1-GISL study.

OBJECTIVE: We performed an external and multicentric validation of the predictive value of abdominal computed tomography (aCT) on time to first treatment (TTFT) in early stage chronic lymphocytic leukemia (CLL) patients. METHODS: aCT was performed at diagnosis in 181 Rai 0 patients enrolled in the O-CLL1-GISL trial (clinicaltrial.gov ID:NCT00917549). RESULTS: Fifty-five patients showed an abnormal aCT. Patients with an abnormal aCT showed a significantly shorter TTFT than those with normal aCT (P < 0.0001). At multivariate analysis, aCT (P = 0.011), ß-2 microglobulin (P = 0.019), and CD38 expression (P = 0.047) correlated with TTFT. Following IWCLL 2008 criteria, 112 (61.9%) cases remained at Rai 0, while 69 (38.1%) satisfied the criteria of clinical monoclonal B-cell lymphocytosis (cMBL). Reclassified Rai 0 patients with an abnormal aCT showed a significantly shorter TTFT than those with a normal aCT (P < 0.0001). At multivariate analysis, only aCT (P = 0.011) correlated with TTFT. Eleven cMBL cases (15.9%) showed an abnormal aCT and were reclassified as small lymphocytic lymphomas (SLL); nonetheless, TTFT was similar for cMBLs and SLLs. CONCLUSION: Our results confirm the ability of the abnormal aCT to predict progression in early stage cases.

The genotype of MLH1 identifies a subgroup of follicular lymphoma patients who do not benefit from doxorubicin: FIL-FOLL study.

Though most follicular lymphoma biomarkers rely on tumor features, the host genetic background may also be relevant for outcome. Here we aimed at verifying the contribution of candidate polymorphisms of FCγ receptor, DNA repair and detoxification genes to prognostic stratification of follicular lymphoma treated with immunochemotherapy. The study was based on 428 patients enrolled in the FOLL05 prospective trial that compared three standard-of-care regimens (rituximab-cyclophosphamide-vincristine-prednisone versus rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone versus rituximab-fludarabine-mitoxantrone) for the first line therapy of advanced follicular lymphoma. Polymorphisms were genotyped on peripheral blood DNA samples. The primary endpoint was time to treatment failure. Polymorphisms of FCGR2A and FCGR3A, which have been suggested to influence the activity of rituximab as a single agent, did not affect time to treatment failure in the pooled analysis of the three FOLL05 treatment arms that combined rituximab with chemotherapy (P=0.742, P=0.252, respectively). These results were consistent even when the analysis was conducted by intention to treat, indicating that different chemotherapy regimens and loads did not interact differentially with the FCGR2A and FCGR3A genotypes. The genotype of MLH1, which regulates the genotoxic effect of doxorubicin, significantly affected time to treatment failure in patients in the rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone arm (P=0.001; q<0.1), but not in arms in which patients did not receive doxorubicin (i.e., the rituximab-cyclophosphamide-vincristine-prednisone and rituximab-fludarabine-mitoxantrone arms). The impact of MLH1 on time to treatment failure was independent after adjusting for the Follicular Lymphoma International Prognostic Index and other potential confounding variables by multivariate analysis. These data indicate that MLH1 genotype is a predictor of failure to benefit from rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone treatment in advanced follicular lymphoma and confirm that FCGR2A and FCGR3A polymorphisms have no impact when follicular lymphoma is treated with rituximab plus chemotherapy (clinicaltrials.gov identifier: NCT00774826).

Cometary science. The morphological diversity of comet 67P/Churyumov-Gerasimenko.

Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency's Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material.

Cometary science. On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko.

Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss.