Clinical response to everolimus in a patient with Hodgkin's lymphoma harboring a TSC2 mutation

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Citation: Blood Cancer Journal (2016) 6, e420; doi:http://dx.doi.org/10.1038/bcj.2016.25

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LETTER TO THE EDITOR

Clinical response to everolimus in a patient with Hodgkins lymphoma harboring a TSC2 mutation

Blood Cancer Journal (2016) 6, e420; doi:http://dx.doi.org/10.1038/bcj.2016.25

Web End =10.1038/bcj.2016.25 ; published online 13 May 2016

Hodgkins lymphoma (HL) is a lymphoid malignancy that has a high cure rate with modern chemoradiation regimens.1 However, about 1020% of patients with advanced stage HL develop relapsed or progressive disease,1 with 5% of patients presenting with primary progressive HL that has a 5-year overall survival of only 26%.2 It is of paramount importance to develop novel treatments for this population of patients. Recently, several novel drugs were found to be active in refractory and/or relapsed HL, including the anti-CD30 monoclonal antibody brentuximab vedotin,3 the anti-PD1 monoclonal antibody nivolumab4 and the mTOR inhibitor everolimus.5 In a phase II clinical trial, everolimus

was shown to induce responses in 47% of patients with relapsed HL, including one patient who achieved clinical complete remission (CR).6 However, the lack of biomarkers for response are one of the many challenges that preclude a more widespread use of this drug in the therapy of HL. The advent of next-generation sequencing may help to determine molecular bio-markers associated with response to a specic drug, particularly when patients with an exceptional response are evaluated.7

We herein report the case of a female patient with primary refractory HL that achieved a near CR with single-agent ever-olimus. Genomic analysis of the tumor at the time of progression to the last therapy demonstrated damaging mutations of the TSC2 gene that may lead to increased mTOR pathway activation.

A 31-year-old female patient was diagnosed with stage IVB nodular sclerosis HL in July 2012. She had primary refractory

Figure 1. (a) Positron emission tomography-computed tomography (PET-CT) prior to start of everolimus therapy. (b) PET-CT after 2 months of therapy with single-agent everolimus.

Letter to the Editor

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disease and did not respond to ABVD and several different salvage chemotherapeutic regimes, including ICE, GNP, DHAP, BEACOPP, IVAC and bendamustine. She never underwent autologous peripheral blood stem cell transplantation due to lack of chemosensitive disease. She was treated with brentuximab vedotin, but had disease progression after six cycles, presenting with lung and pleural involvement and compression of spinal roots (Figure 1a). Patient was then started on therapy with off-label everolimus, based on the results of the aforementioned clinical trial, as she was considered to be refractory to chemotherapy.5 After 2 months of therapy with single-agent everolimus (10 mg orally once daily), a new positron emission tomography-computed tomography scan showed that the patient had achieved a near CR (Figure 1b) with disappearance of most sites of disease and 490% reduction in the remaining sites.

As she had no HLA-matched donors, she underwent haploidentical allogeneic stem cell transplantation 1 month after achieving a response to everolimus. Unfortunately, she passed away due to transplant-related complications (cytomegalovirus pneumonia) on day +68.

Because of this patient-signicant response to everolimus, an inhibitor of the PI3K-Akt-mTOR pathway, we hypothesized that this patients tumor might harbor mutations associated with increased activity of this pathway. We sent the formalin-xed parafn-embedded block of a lymph node biopsy done at the time of disease progression on brentuximab to be analyzed by means of a comprehensive targeted next-generation-sequencing-based genomic proling (FoundationOne Heme, Cambridge, MA, USA) using DNA and RNA in a CLIA certied laboratory (Foundation Medicine). This method consists of the analysis of the entire coding sequence of 405 cancer-related genes, 31 selected introns frequently involved in rearrangements and RNA sequencing of 265 genes commonly fused in cancer, to a median coverage of 4500x and 420 000 000 reads. No microdissection of ReedSternberg cells was performed. No germline DNA was available for sequencing. The results revealed 21 genomic abnormalities, including a missense mutation on gene TSC2. The V1711M mutation on TSC2 is a conservative missense mutation localized on the Rap-GAP domain of the tuberin protein. The sorts intolerant from tolerant score (in silico tool that predicts whether changes in amino acids in protein sequences are deleterious) was0.02, suggesting that this mutation is damaging. Furthermore, this mutation has been previously reported in a patient with squamous cell skin carcinoma of the face.8 Besides the TSC2 mutation, several other oncogenic variants were detected (Table 1).

Inactivating mutations on TSC2 and TSC1 have been described in tuberous sclerosis,6,9 and the TSC1TSC2 complex is a critical negative regulator of mTOR complex 1(mTORC1).10 Within the TSC1TSC2 complex, TSC1 stabilizes TSC2, whereas TSC2 acts as a GTPase-activating protein (GAP) for the small GTPase Rheb (Ras homolog enriched in brain).11,12 When active, the TSC1TSC2 complex inhibits mTORC1 by stimulating the conversion of Rheb-GTP to Rheb-GDP.11,12 Therefore, the ability of a variety of upstream pathways to affect mTORC1 activity is dependent on modications that functionally inhibit or activate the TSC1TSC2 complex. The GAP domain, where the V1711M mutation is located, is crucial for TSC2 function,9 and loss of TSC2 activity may lead to mTORC1 pathway activation.11,12

It has been suggested that TSC1/TSC2 inactivation predicts for responses to mTOR inhibitors. Indeed, TSC1 mutations have been found in 8% of bladder malignant tumors, and are correlated with sensitivity to everolimus.13 In another report, a nonsense mutation in TSC2 (Q1178*) was described in a patient with anaplastic thyroid cancer who had an impressive response to everolimus.14 Activation of the mTOR pathway is found in the majority of cases of HL and HL cell lines,15 but the mechanisms that lead to this increased activity are currently unknown.5

We herein describe the rst case of TSC2 mutation in a patient with advanced HL who had an impressive clinical response to

everolimus. One limitation of this report is that no functional studies were done to conrm the oncogenic role of this particular TSC2 mutation in HL. However, we do believe that the response to everolimus seen in this case suggests that mutations of TSC2 and other genes of the mTOR pathway should be further investigated in patients with HL.

CONFLICT OF INTEREST

PVC, SA and JSR are employees of Foundation Medicine Inc.

GF Perini1, PV Campregher1,2, JS Ross2,3, S Ali2, N Hamerschlak1 and FPS Santos1

1Centro de Oncologia e Hematologia Familia Dayan Daycoval, Hospital Israelita Albert Einstein, So Paulo, Brazil;

2Foundation Medicine Inc, Cambridge, MA, USA and

3Department of Pathology and Laboratory Medicine, Albany Medical Center, Albany, NY, USA E-mail: mailto:[email protected]

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REFERENCES

1 Connors JM. I. Hodgkin lymphoma: special challenges and solutions. Hematol

Oncol 2015; 33(Suppl 1): 2124.2 Josting A, Rueffer U, Franklin J, Sieber M, Diehl V, Engert A. Prognostic factors and treatment outcome in primary progressive Hodgkin lymphoma: a report from the German Hodgkin Lymphoma Study Group. Blood 2000; 96: 12801286.3 Younes A, Bartlett NL, Leonard JP, Kennedy DA, Lynch CM, Sievers EL et al. Brentuximab vedotin (SGN-35) for relapsed CD30-positive lymphomas. N Engl J Med 2010; 363: 18121821.4 Ansell SM, Lesokhin AM, Borrello I, Halwani A, Scott EC, Gutierrez M et al. PD-1 blockade with nivolumab in relapsed or refractory Hodgkin's lymphoma. N Engl J Med 2015; 372: 311319.5 Johnston PB, Inwards DJ, Colgan JP, Laplant BR, Kabat BF, Habermann TM et al. A phase II trial of the oral mTOR inhibitor everolimus in relapsed Hodgkin lymphoma. Am J Hematol 2010; 85: 320324.6 European Chromosome 16 Tuberous Sclerosis C. Identication and characterization of the tuberous sclerosis gene on chromosome 16. Cell 1993; 75: 13051315.7 Marx V. Cancer: a most exceptional response. Nature 2015; 520: 389393.8 Durinck S, Ho C, Wang NJ, Liao W, Jakkula LR, Collisson EA et al. Temporal dissection of tumorigenesis in primary cancers. Cancer Discov 2011; 1: 137143.

Table 1. Oncogenic genomic alterations found

Known drivers and potential driver mutations

Gene AA change VAF (%) or fold amplication

TSC2 p.V1711M 50 DNMT3A p.P896L 11 PTCH1 p.G288D 12 ATR p.W2104* 7 BRCA2 p.R2842C 42 B2M p.M1I 13 B2M p.M1K 26 MSH6 p.T1219I 9 TP53 p.K291N 19 TP53 p.R248Q 21 ASXL1 p.Q1517* 9 XPO1 p.E571K 32 AXIN1 p.P24S 9 FBXO11 p.R640fs*5 9 CD36 p.Y325* 51 CDC73 Splice site (c.370+1G4A) 10

JAK2 Amplication 11x CD274 Amplication 11x PDCD1LG2 Amplication 11x CCND3 Amplication 22x KDM4C Amplication 11x

Abbreviations: AA, amino acid; VAF, variant allele fraction.

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9 Niida Y, Lawrence-Smith N, Banwell A, Hammer E, Lewis J, Beauchamp RL et al. Analysis of both TSC1 and TSC2 for germline mutations in 126 unrelated patients with tuberous sclerosis. Hum Mutat 1999; 14: 412422.

10 Tee AR, Fingar DC, Manning BD, Kwiatkowski DJ, Cantley LC, Blenis J. Tuberous sclerosis complex-1 and -2 gene products function together to inhibit mammalian target of rapamycin (mTOR)-mediated downstream signaling. Proc Natl Acad Sci USA. 2002; 99: 1357113576.

11 Tee AR, Manning BD, Roux PP, Cantley LC, Blenis J. Tuberous sclerosis complex gene products, tuberin and hamartin, control mTOR signaling by acting as a GTPase-activating protein complex toward Rheb. Curr Biol 2003; 13: 12591268.

12 Inoki K, Li Y, Xu T, Guan KL. Rheb GTPase is a direct target of TSC2 GAP activity and regulates mTOR signaling. Genes Dev 2003; 17: 18291834.

13 Iyer G, Hanrahan AJ, Milowsky MI, Al-Ahmadie H, Scott SN, Janakiraman M et al. Genome sequencing identies a basis for everolimus sensitivity. Science 2012; 338: 221.

14 Wagle N, Grabiner BC, Van Allen EM, Amin-Mansour A, Taylor-Weiner A, Rosenberg M et al. Response and acquired resistance to everolimus in anaplastic thyroid cancer. N Engl J Med 2014; 371: 14261433.

15 Mark A, Hajdu M, Varadi Z, Sticz TB, Nagy N, Csomor J et al. Characteristic mTOR activity in Hodgkin-lymphomas offers a potential therapeutic target in high risk disease--a combined tissue microarray, in vitro and in vivo study. BMC Cancer 2013; 13: 250.

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