Translating Combinations of Radiation Therapy and Immunotherapy to the Clinic

Name: Translating Combinations of Radiation Therapy and Immunotherapy to the Clinic
Uploaded: 2025-03-12T13:58:35.2766667Z
Duration: 56 min 51 s

March 12, 2025

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00:00Your attention. Thank you all
00:01for coming.
00:03It is really my great
00:04pleasure,
00:06to introduce Sandra Demaria.
00:10She is a,
00:12she's a a a very
00:14well renowned,
00:15physician scientist.
00:17She did her training,
00:18in medical school,
00:20at the Universita
00:22Universita
00:23Delhi,
00:25Studi in Italy,
00:27then came to the US,
00:29did a postdoc in immunology,
00:31did her residency in pathology
00:32at NYU and stayed there,
00:34rose up the ranks, to
00:36become a full professor,
00:38at NYU and then,
00:40moved on to Weill Cornell
00:42as a professor in,
00:44pathology and radiation oncology,
00:47in two thousand fifteen.
00:49And in her career, doctor
00:50Demaria has several notable accomplishments,
00:54on both the clinical and
00:56scientific or basic science fronts.
00:59On the clinic, she's played
01:00a fundamental role in establishing
01:02guidelines for evaluating,
01:04tumor infiltrating
01:06lymphocytes
01:06in breast cancer.
01:09And in the laboratory, she's
01:10she's really helped to usher
01:12in,
01:13new understandings
01:14about the crosstalk between,
01:17DNA damage, radiation,
01:19and the immune system.
01:21And,
01:22she's she's done so much
01:24work with radiation oncology that
01:25many think she is a
01:26radiation oncologist. And in fact,
01:28we'd love to claim her
01:29as a radiation oncologist.
01:31But I think that just
01:32goes to show, you know,
01:34how her work is having
01:35an impact
01:36across multiple specialties,
01:39in oncology. And so we're
01:40very lucky to have her
01:41here and invite her here
01:42as a distinguished lecturer.
01:44So I'd like to present
01:45this to you. We'll get
01:46a picture afterwards.
01:48Okay.
01:49And if you can all
01:49help me give her a
01:50a very warm welcome.
01:57Thank you very much for
01:58the very nice introduction and
02:00for the invitation. It's great
02:02to be here and for
02:03the present that
02:05I,
02:06did not,
02:07expect.
02:09So I will,
02:11these are my disclosures,
02:14and,
02:16I'm gonna tell you, today
02:18about
02:19sort of the background
02:21for the work I've been
02:22doing for the last now
02:24more than twenty years.
02:26And and so we know
02:27that T cell devoid called
02:29tumors
02:31can evade
02:32immune recognition,
02:34in multiple steps, and the
02:36main ones,
02:37they may fail to to
02:38to express
02:40immunogenic
02:41antigen or produce signal
02:43that attract the antigen presenting
02:45cell, the cross presenting dendolytic
02:47cells.
02:48They can also
02:49exclude the T cells in
02:51multiple way, and
02:54they can produce
02:55immunosuppressive
02:56signal.
02:57And, the reason,
02:59radiation is
03:01an opportunity
03:02to improve immunogenicity
03:04of tumor is that it
03:06can have effect of each
03:07of these steps and,
03:09I will provide some example
03:11of this,
03:12today,
03:13in in my lecture.
03:16So what,
03:18got me into the field
03:19as as an immunologist,
03:22in early two thousand was
03:23a new data that coalesced
03:25to showing actually that antigen
03:27presenting cells would take up
03:29antigen from from dying cells.
03:32And,
03:33this this
03:35could be,
03:36activating T cell responses. And,
03:40you know, after
03:41building on work by, by
03:44my group and many others,
03:47we we kind of build
03:49this initial
03:50working model
03:51showing the concept that,
03:54cells after radiation,
03:57would would die, would also
03:58die, what is being called
04:00by the work of of
04:02Lawrence Ziegvogel and with the
04:03clonal immunogenic
04:05cell death.
04:06Basically, a death that is
04:07stressful
04:08and is coupled with the,
04:10expression of dangerous signal that
04:13can activate the dendritic cells
04:15and also increase the uptake
04:17of the dying cells by
04:18the dendritic cells.
04:20Then the dendritic cells then
04:23take these antigens to the
04:24reining lymph node where they
04:26activate t cells, and then
04:28the activated T cells come
04:30back to the tumor and
04:31in the tumor,
04:32they
04:34do recognize
04:37there is also effects of
04:38radiation that favor the infiltration
04:41because there is increased
04:44expression of additional molecule on
04:47the vascular endothelium,
04:49production of chemokine that,
04:51attracted the effect of T
04:53cells to the tumor, and
04:54then the the cancer cells
04:55that have survived often are
04:57modified expressing increased level of
05:00MHC plus one,
05:02presenting,
05:03antigens
05:04and expressing also increased level
05:06of NKG two d ligand,
05:08all which can favor recognition
05:10and elimination of the t
05:11cells
05:12or the cancer cells by
05:14the T cells, and of
05:15course this can fuel a
05:16process
05:17that has been nicely defined
05:19by by Ira Melman and
05:21and then China's the cancer
05:23immunity cycle while this process
05:25can fuel an increase in
05:27antitumor immune response.
05:29So my, sort of interest
05:31in radiation was really to
05:32see can we generate, can
05:34we use it to actually
05:35generate cell responses
05:37in tumors that are otherwise
05:39unresponsive
05:40to to immune checkpoint inhibitors?
05:43And we have used two
05:44type of,
05:45mouse model to test,
05:47this hypothesis. One where we
05:50injected cells into different flanks
05:53of the mouse, one that
05:54was irradiated, the other was
05:56outside of the field of
05:57radiation.
05:59And
06:00another type of model is
06:01a spontaneously metastatic model when
06:03you can irradiate
06:05the tumor,
06:06let's say, the primary tumor,
06:08and then look for control
06:10of lung metastases.
06:14And and,
06:15these models are all not
06:17responsive
06:18to anti CTLA fall,
06:21but the you know, so
06:22the question we were asking
06:23is can we induce responsiveness
06:27in systemic anti tumor
06:29effect by combining with radiation.
06:32And again, most of
06:35we really focus more on
06:36anti CTLA four than other
06:38checkpoint inhibitors because anti CTLA
06:40four,
06:41plays a a a big
06:43role at priming of T
06:44cells,
06:45much more so that the,
06:47anti PD one and PDL
06:49one agent. So seeing the
06:50ideal,
06:52checkpoint inhibitors to combine with
06:55radiation.
06:56And, of course, in a
06:57clinic, the same concept was
06:59that, okay, you have a
07:00patient now responsive
07:01to to checkpoint inhibitors,
07:03you irradiate
07:04one site,
07:06which will generate T cells
07:08that then can be mediated
07:10systemic responses.
07:13So in mice model, this
07:14is an example of when
07:16this is successful, how it
07:18looks. This is an example
07:20from BioWorks,
07:21the TSA is a mammary
07:23carcinoma in MelpSimise.
07:25So the, irradiated tumor,
07:29the the the the model
07:31doesn't respond at all with
07:32the twenty six g l
07:33four,
07:36treatment by itself.
07:38But when you,
07:40irradiate one side, you see
07:42a nice tumor growth delay
07:43on the irradiated side, but
07:45not the control lateral side.
07:47Radiation indeed by itself
07:49has some immunogenic
07:51effect, but not sufficient to
07:53be,
07:54really,
07:55sort of relevant or to
07:57induce what are known as
07:58a scopal effect. It's extremely
08:00well,
08:01effect seen in the in
08:03the clinic.
08:05But now what happened is
08:07when you combine it with
08:09CTLA fold, you see actually
08:10an improved,
08:12control of the elevated tumor.
08:13And now you also see
08:14control of the controlled lateral
08:16tumor. And in mice, of
08:17course, we can prove this
08:19is completely dependent on CD80
08:20cells because you can deplete
08:22CD80 cells and show that
08:24the effect,
08:25is gone.
08:28So another thing that we
08:30were exploring and this was
08:32really
08:33the sort of
08:35not being myself as an
08:36additional oncologist, I've been working
08:38very closely
08:39with my long term colleague,
08:41collaborator, and friend, Sylvia Formante.
08:44She was, you know, telling
08:46us, well, you have to
08:47compare different additional doses. So
08:49we chose three different doses.
08:51There was a lot of
08:52talk about larger,
08:54sort of ablative doses, maybe
08:56in mal immunogenics. So we
08:58tested this in a mass
08:59model, and we actually found
09:01that the best synergy with
09:02the NTGLA four, particularly in
09:04control of the,
09:06the non irregularity tumor was
09:08achieved with the hyperfractionated
09:10regimen, the best being a
09:12grade times three. And and
09:14so we went on and
09:15analyzed the tumors shortly after
09:17completing radiation to see what
09:19was different.
09:20And there was this regulation
09:22of this pathway,
09:23here that was seen only
09:25in two months,
09:26that received at a greater
09:28time three, and this is
09:29type one interferon pathway.
09:31And so we then treated
09:33the cancer cells in vitro,
09:35and we also saw the
09:36same thing that they make
09:37interferon
09:38when they are infected by
09:39a virus, so when they
09:40are treated with radiation, and
09:42it is a more pronounced
09:43effect with this hyperfactionated
09:46regimen. And basically,
09:48sort of, you know, getting
09:49us to think that indeed
09:51radiation,
09:52activates works
09:54by activating
09:55a pathway that are canonical
09:57pathway of viral defense since
09:59type one interphenol is obviously
10:01a main,
10:03mediator,
10:05cytokine activated,
10:06in viral infections.
10:08And, of course, the,
10:10you know, sort of
10:12seminal work by Jen Chen,
10:16had shown that CIGAS,
10:18is the actual sensor for
10:21DNA in the cytosol that
10:23activates,
10:24then downstream,
10:26sting and and then,
10:28sting activates
10:30phosphoryl leads to phosphorylation ILF
10:32three and TBK one, and
10:34and and then ILF three
10:35activates type one interference
10:39transcription.
10:40And and so this was
10:43shown in a setting on
10:44violent infection, and we thought,
10:46well, radiation,
10:47is doing the same, and
10:49we did the down regulating
10:51the cancer cells, ligand, and
10:54this would obligate completely the
10:56regulation of Taiwan interferon,
11:00by radiation or by, again,
11:02a viral infection. And we
11:03went on to do a
11:05lot more work showing that
11:06it was also important,
11:08of course, in vivo for
11:09the synergy
11:10of radiation and inter CTLA
11:12fault.
11:14But the,
11:16you know, many other groups
11:18have have shown the same
11:19thing,
11:21and have actually
11:23demonstrated
11:23that
11:25the formation of micro nuclei
11:26is one way that the
11:28DNA after radiation,
11:31gain,
11:32sort of is is is,
11:34pleasant in the cytoplasm
11:36of the cells
11:37and that,
11:40which since micronuclear membrane is
11:42very,
11:43sort of is small is
11:44small attenuated, is more fragile,
11:46easily breakdown exposing the DNA
11:49to CIGAS sensing.
11:51Also damaged mitochondria
11:53can contribute
11:54to stimulation of cigars
11:57by exposing the mitochondrial DNA,
12:00after radiation.
12:01And, of course, there are
12:02many
12:04regulatory
12:05points to these pathways.
12:08More and more that are
12:09constantly
12:10described. We did found the
12:12Tlex1,
12:13which is the nextonuclease
12:15that digest cytoplasmic DNA and
12:17is in fact very important
12:19to protect us from some
12:20autoimmune diseases such as Icardi
12:23Gouthiere, but also implicating
12:25in some subtype of lupus.
12:28So AUTREX one was actually
12:29a counter in addition induced
12:31activation by digesting the cytosol
12:34cytosolic DNA,
12:36And more recently, the group
12:37of David Balbi had actually
12:39shown that,
12:40TRX1 is kind of like
12:42an induced regulatory pathway in
12:44the sense that, when you
12:46have a strong interference signal,
12:48you get more TRX1
12:49being,
12:51regulated and and there is
12:53information about many other pathway
12:55that may regulate
12:56this balance between,
12:59you know,
13:00digesting the cyto the the
13:02cytosolic DNA and and
13:05actually producing it,
13:07which are, of course,
13:09critical
13:10as you would expect in
13:11autoimmune diseases,
13:14and and infections as well.
13:16And again, autophagy,
13:18as as my
13:20friend Lorenzo Galluzzi showed can
13:22actually preclude
13:24exposure
13:25of the damaged,
13:27DNA from of of the
13:29DNA from damaged mitochondria. This
13:31is again another pathway that
13:33can reduce
13:34the activation of type one
13:35interferon by radiation.
13:38And why is, type one
13:39interferon so important? Well, it
13:42has been shown,
13:44to to recruit
13:47the
13:47cross presented dendritic cell to
13:49the tumor and that's exactly
13:51what we saw that we
13:52had an increase in cross
13:53presented dendritic cells in the
13:55tumors that were irradiated when
13:57there was induction type one
13:59interferon
14:01and in this, in this
14:03dendritic cells were also more
14:05activated.
14:08And so
14:10as
14:12this, you know, the central
14:13focus of my work is
14:15really trying to understand
14:17how this,
14:18generation or this in situ
14:20vaccination effect by radiation
14:23occurs.
14:24And so there are multiple
14:25steps,
14:27to to generate
14:28a T cell response, the
14:30recruitment of dendritic cells, the
14:32uptake of dying cancer cells,
14:34the,
14:35maturation,
14:36and then their activation migration
14:38to drain and lift and
14:39nod and so on. And
14:40again, interferon can have an
14:42important role in this initial
14:44step and we know the
14:45recruitment of dendritic cells is
14:48really critical for development of
14:50anti tumor responses and and
14:52response to checkpoint inhibition in
14:54general. And this is really
14:55work by Stephanie Splanger, with
14:57Tom Galeski, and,
15:00Gaetano Leisso Souza's team that
15:02have done a lot of,
15:04as they demonstrated
15:05a critical role of this
15:07recruitment
15:08of cross presented dendritic cells.
15:10So, okay, this is a
15:12first start that can be,
15:14a stable, can be
15:16induced or enhanced by radiation.
15:19But what about,
15:22all the other steps?
15:23And the first question was,
15:26however, you know, regardless of
15:28all these beautiful mouse work,
15:30does this work at all
15:32in patients?
15:34And so,
15:36we did get a very
15:38encouraging
15:41response.
15:42This was actually a patient
15:43treated under the
15:45compassionate exemption by by Sylvia
15:48Fermenti
15:49who had metastatic lung cancer
15:51to multiple sites. This was
15:53before there was an immunotherapy
15:55approved for non small cell
15:56lung cancer and ipilimumab, the
15:58anti CTLA full agent, had
16:00just been approved
16:03for, had just been approved
16:05for metastatic melanoma, didn't show
16:08much activity in lung cancer.
16:10And so,
16:12the patient was referred to
16:13cilia because they were he
16:14had run out of any
16:15therapeutic option and,
16:18they wanted her to palliate
16:19a a a metastasis in
16:21the bone, actually.
16:23But after talking to the
16:24patient, she decided,
16:27to to, you know, to
16:28test
16:29whether we could induce indeed
16:31a response by combining,
16:34a nine perfluctionate, a regimen
16:36of radiation that they want
16:37to optimize
16:38with the anti CTLA four.
16:40And, the patient received this,
16:43non ablative radiation to one
16:45liver metastasis and went on,
16:47over time and within few
16:49months, he cleared all of
16:50his lesion,
16:51with just this one
16:54radiation dose and four doses
16:56of anti CTLA four, which
16:57is what was approved for
16:59metastatic melanoma.
17:01And while the patient was
17:02responding,
17:04there was a subtle
17:05clavicular lymph node that was
17:06removed because it was still
17:09positive by PETCT.
17:11I looked at the node
17:12and I stayed for CVAT
17:13cell. There was still tumor,
17:14but the tumor was full
17:16of CVAT cell so it
17:17was very encouraging.
17:18The patient became a long
17:19term responder.
17:21As far as I know,
17:22he's still doing well today
17:24without
17:25recurrence and without further treatment.
17:27So this was like, okay,
17:29great, but it sees one
17:30patient and exceptional responses allocation
17:33and is seen. Is this
17:35reproducible? So a prospective trial,
17:38confirmed that actually this combination
17:41can work at inducing systemic
17:43responses in patients,
17:44but it was a non
17:46randomized trial, a small trial,
17:48and I think that most
17:50important thing that we observe
17:52is by studying these patients,
17:55that
17:56we we could prove that
17:57development of T cells
18:00specific for neoantigen
18:02that was pleasant
18:04in the tumor of the
18:05patient
18:07that we we were able
18:08to sequence the treatment.
18:09This was one of the
18:11two complete responders for for
18:13for which we had enough
18:14enough tumor material to to
18:16run the prediction, and we
18:17did indeed found that
18:20this,
18:21this mutation was,
18:23by by following both the
18:25the T cell responses
18:27in terms of functional responses
18:29sequentially
18:29in the blood of the
18:30patient and doing TCR
18:32receptor
18:35sequencing that one of these
18:37T cells
18:39clones that recognized the neoantigen
18:41was actually present in the
18:43tumor, but not detectable in
18:44the blood at baseline and
18:46became elevated very quickly and
18:48remained elevated over time, and
18:50the other one was a
18:51completely new,
18:52T cell clone, that followed
18:55the same type of kinetics
18:56of a sponge when the
18:57patient was rejecting the tumor.
18:59So this kind of supported
19:01the idea that,
19:03this combination so the radiation
19:04can really help generate
19:06tumor specific results,
19:09and and
19:11increase responses to checkpoint inhibitors.
19:14The reality is however that
19:15a lot of randomized trial
19:19did not
19:20really confirm
19:22a clear benefit of radiation
19:25in combined with
19:27checkpoint inhibitors, and I'm showing
19:29here three example.
19:30This one actually, the the
19:31trial by, Willem and Tillen
19:34showed a band showed an
19:35increased response in non small
19:37cell lung cancer in terms
19:38of
19:39response rate and,
19:41disease free survive progression free
19:43survival rather than novel or
19:44survival when addition was added
19:47to pembrolizumab,
19:48but,
19:49the benefit was smaller than
19:53completely negative and there are
19:54additional example
19:56leading us to, you know,
19:57think so. There is something
19:59lost in translation
20:00here.
20:02So if radiation
20:04can indeed promote the degeneration
20:06in tetramer T cells, why
20:08easily doesn't work in many
20:09cases?
20:10We had a a consensus
20:12conference
20:13spearheaded by by NCI,
20:16a few years back,
20:17trying to figure out, you
20:19know, and much of this
20:20discussion was what is the
20:21best radiation doses that should
20:23be used to receiving, you
20:25know, to to to have
20:27immunogenic
20:28effect.
20:29And, you know, we the
20:31the conclusion was really that
20:32the radiation is a different
20:34drug, a different doses,
20:36and low doses
20:37have some effect in increasing
20:40permeability of T cells to
20:41the tumor and this intermediate
20:43type of fractionated doses may
20:44be going to generate some
20:46response in ablative doses can
20:48do a lot of other
20:48thing including
20:49potentially the bulking which can
20:51be beneficial in increasing response
20:53to checkpoint inhibitors
20:55or reducing tumor heterogeneity.
20:59But, it's obviously there is
21:01no, you know, clear consensus
21:02to this day what is
21:04the best course. But I've
21:06been,
21:06really
21:08keeping understanding
21:10the radiation
21:11effect in terms of generating
21:14an insight of a scene
21:15and vaccinating the patient.
21:17And so
21:19to to do this, we
21:20we,
21:21went back,
21:23to to some of our
21:24mouse models,
21:26particularly to the forty one
21:28model. This was,
21:30this is a mammary carcinoma
21:32that is very, very aggressive,
21:33very metastatic,
21:35and it was the first
21:35tumor that we tested back
21:38in, you know, in the
21:40early two thousand in combination
21:41with the four, and this
21:43was actually initially a collaboration
21:45with, with Gmelis and gave
21:46us the the antibody. This
21:48was far before it was,
21:50you know, shown to to
21:51to work in patients.
21:52And we saw that indeed
21:54if you evaluated the tumor,
21:56you increase survival of the
21:57mice. It was due to
21:58control of lung metastases in
22:00the draining lymph node. We
22:01could detect CDT cells specific
22:03for the tumor antigen only
22:05when radiation and the CTLA
22:07four were combined, but not
22:09alone. We went on to
22:10show that these cells were
22:12present in the tumors and
22:13so on. But the bottom
22:15line is that,
22:16the mice are rarely cured,
22:19and, you know, you see
22:20an effect, but it's not,
22:22really good enough. And so
22:24we thought this may be
22:25a good model to try
22:26to understand what is the
22:27interaction between radiation and interstitial
22:29effluent and potentially
22:31how to improve it. And
22:33so this work was led,
22:35by Nils Luttwist when he
22:37was in the lab,
22:39and,
22:40he did,
22:42salt
22:43T cell from the tumors
22:45of the mice
22:47and did single cell,
22:49analysis.
22:51The the data, the convolution
22:53using projectil, which is specific
22:55for mice t cells,
22:57resolved,
22:58sort of, you know,
23:00major subset. The largest been,
23:02CD eight exhausted t cells.
23:04Then the question was what
23:06the treatment is doing. So
23:08radiation by itself seems to
23:09actually increase
23:11CD80 cells, but they are
23:12exhausted CD80 cells while inter
23:14CTLA form may be not
23:16supplies, they increase the TH1
23:18light T cells. But only
23:19when they are combined, there
23:20was a reduction in regulatory
23:22T cells and an increase
23:24in functional subset of CD80
23:26cells that have been associated
23:28with response to checkpoint inhibitors
23:30such as CD8 effector mainly,
23:32tip like also exhausted and
23:34early activation T cells. And
23:36these T cells were also
23:37more clonal.
23:39So the the exhausted T
23:40cells are clonal even in
23:42a a known treating mice.
23:44There are just a lot
23:45less.
23:46But, the
23:48the actual cell the the,
23:52effectual name ALICIA T cells
23:54really were not clonal and
23:56became clonal only in the
23:57combination treatment group.
23:59And only in this group
24:00we saw actually
24:02T cells that was specific
24:03for the tumor antigen where
24:05we had the destinelle that
24:06could actually,
24:08you know, identify these T
24:09cells in a single cell
24:11experiment and the same was
24:12true for the early activation
24:14CD a T cell. So
24:15all of these,
24:16seems to be good, but
24:18still the largest subset was
24:20made of exhausted CD a
24:22T cells. So, Maud
24:24Charpentier, another postdoc in the
24:26lab,
24:27performed a multiplexing,
24:29flow cytometry experiment to characterize
24:31which subset were placed within
24:34these exhausted c d a
24:35t cells. And she found
24:36that there was a small
24:37subset of really bad exhausted
24:39T cells with high expression
24:41of digits,
24:42like three,
24:44and and ting three.
24:46But the largest subset here
24:48was actually
24:49low in p g one,
24:51was negative fourteen three, but
24:53he had high LAG three
24:55expression. So we thought maybe,
24:57that's a target that we
24:58should go after to improve
24:59responses in the CD4 compartment.
25:02There was high expression
25:04of ox forty,
25:06and
25:07by conventional T cells, but
25:09even much small by regulatory
25:11T cells, and it was
25:12actually increased by radiation in
25:14regulatory T cells, so we
25:15thought these may be other
25:17targets to go after.
25:19And finally, the TH one
25:21T cells had actually quite
25:23low expression of CD forty
25:25ligand,
25:27and so maybe they weren't
25:28sufficiently
25:30able to help.
25:32And so we
25:33decided to test,
25:35the addition
25:37of all of these different,
25:39sort
25:40of immunotherapies
25:42to the baseline. This is
25:43a baseline response you get
25:45with radiation CTLA four.
25:47So your some
25:49sometimes complete, but often incomplete
25:51tumor regression.
25:53And now we added in
25:55top of this anti PD
25:56one, no benefit. Anti leg
25:58of C, no benefit. Ghetal,
25:59no benefit. Oxfault, no benefit.
26:01Even combination of PD one
26:03and Ghetal, no benefit. When
26:05we had the CD4 TiagoNIST,
26:06the picture was completely different
26:08and this was very
26:09kind of revealing
26:11to us and we repeated
26:12also with the testing individual
26:15agent to to confirm the
26:16texture. You really need the
26:17combination of FLIR radiation
26:19in the CTLA four and
26:21CD4 T agonists
26:22to get this type of
26:23responses.
26:24And we did a lot
26:26of other work that are
26:27really not going,
26:28in the interest of time,
26:29but showing that indeed you
26:31really activate the dendritic cells
26:33compartment and you increase timing
26:35of CD80 cells in the
26:37gliomy lymph node that's kind
26:38of summarized here. And it
26:40looks like at least in
26:42in this type of tumor,
26:44this is a model of
26:45triple negative breast cancer,
26:47which has a heavy suppressive
26:49myeloid compartment.
26:51The additional one only drives
26:52in a few more exhausted
26:54T cells. When you add
26:55CTLA four, you improve the
26:56functionality of T cells, but
26:58you really need CD4 to
27:00start the system and
27:03and
27:04really reinforce and amplify
27:07the priming
27:08of,
27:09of new T cells that
27:10then go back to the
27:11tumor from the brain and
27:12lymph node.
27:14Now CD4 Tiago
27:16do have some systemic toxicity,
27:18and we start actually exploring
27:20whether the benefit is really
27:22local, which is suggested by
27:24quite
27:25several several works out there.
27:28But we decided
27:30because
27:31injecting,
27:32antibody into tumor, they see
27:34compounding to tumor is is
27:36sort of a difficult technique
27:38that can be
27:40leading to very valuable results.
27:41And so we started working
27:43with a bioengineer,
27:45Alessandro Gattoni at, Eosomethodiste
27:48actually was designed a device,
27:51nanofluidic
27:52drug eluting state
27:53that can be,
27:55implanted to the tumor and
27:56release over time,
27:58different compound including antibody.
28:01And so this is kind
28:02of
28:03another
28:04area that we are exploring
28:06and initial
28:07results in the mice
28:09seem promising that the antibodies
28:11released
28:12in the tumor
28:13is actually
28:15efficacious
28:16in terms of the therapeutic
28:19effect, but a much more
28:21work to be done.
28:24And,
28:25so so again,
28:27here going back to this,
28:29to this scheme and the
28:30different steps that are required
28:32to generate an antitumor response,
28:35we can
28:36help the the,
28:38optimal activation of dendritic cells
28:40with the CD four t
28:41agonist.
28:42But what about the,
28:44uploading the antigen here? And
28:46so we,
28:47looked at the,
28:50different
28:51molecules that there are different
28:53molecules that can
28:55either favor uptake
28:56of,
28:57dying cancer cells
28:59by dendritic cells and and
29:01by myeloid cells in general
29:03or can actually counter,
29:05the, the uptake.
29:07And we focus on the
29:09interaction between c d forty
29:11seven and sulfalfa.
29:13Particularly
29:14focusing on inhibiting sulfalfa because
29:17sulfalfa,
29:19when interacts with c d
29:21forty seven,
29:22it is first of all,
29:23sulfur is expressed on,
29:25mostly
29:26on myeloid
29:27cells, while c d forty
29:29seven is expressed pretty much,
29:31on many different cells
29:33in the in the body,
29:34including red blood cells and
29:36blocking c d forty seven
29:38as,
29:40some, you know, as different
29:42effects and different,
29:44issues that,
29:45I think many of you
29:46are aware. But
29:48the,
29:49so alpha importantly signals directly
29:52in the in the in
29:53the myeloid cells when engaged
29:56and it includes,
29:58SHIP one two and obligates
30:00phagocytosis
30:01listed in in macrophages. So
30:03it seemed to be a
30:04good target to explore.
30:06So first,
30:07we used two different models,
30:10the TSA, mammary carcinoma in
30:12the MARC C background, and
30:14eighty three is in a
30:16triple negative breast cancer
30:18in
30:19c fifty seven black six
30:21mice. And we tested whether
30:23they have,
30:25you know, what what happens
30:27when you inflate the mice
30:28with the sulfalfa
30:29blocking antibody,
30:31and radiation. So the sulfalfa
30:33blocking antibody by itself has
30:34no effect in either
30:36model. Radiation,
30:38cause a tumor growth delay,
30:40and when combined with,
30:42sulfalfa,
30:43is actually much more effective,
30:46in, in inducing tumor regulation,
30:49and we actually have seen
30:50also
30:51some ability to induce control
30:53of a non irradiated tumor.
30:54The AT three model is
30:56actually
30:57completely resistant to radiation use
30:59at day grade time three,
31:00but when you add the
31:02cell partial blocking antibody, now
31:04you have a significant
31:06tumor, control,
31:08which was,
31:09of course, very interesting. And
31:11we went on to to
31:12ask whether it's just due
31:13to,
31:15a sort of activation of
31:17increased phagocytosis
31:18by macrophages
31:19or whether dendritic
31:21cells are are really, required.
31:23And so we used to
31:24do this,
31:25the,
31:26kinetic bone marrow,
31:28model,
31:29where we reconstitute
31:30mice with either wild type
31:32cells or cells from from,
31:34transgenic mice that have a,
31:38the diphtheria tocil receptor, the
31:40control of a promoter
31:41that is selectively spliced only
31:43on conventional dendritic cells.
31:46And and then we treated
31:47the mice as usual and
31:48depleted disease with diphtheria toxin.
31:50And when we did that,
31:51we completely lost the therapeutic
31:54effect,
31:55of the combination,
31:56indicating that dendritic cells are
31:58really critical.
31:59Now,
32:02the one issue that, you
32:03know, that was always puzzling
32:05and we know that CDC
32:06one are the key cross
32:08trans cross presenting dendritic cells
32:10that are required for generating
32:12anti tumor immune responses, but
32:14they don't really express
32:15sulfalfa.
32:16Sulphalfa is expressed by CDC
32:18two among conventional
32:20dendritic cells at high level.
32:22And so we decided to
32:23understand what is happening,
32:25and and to do this,
32:26we we did site seek,
32:30analysis
32:31of the, immune infiltrator
32:33in the tumors
32:35after
32:37completing
32:38radiation and two of the
32:39doses of the anti c
32:41falafel antibody.
32:43And so this
32:45actually
32:45was able to resolve
32:48a free subset
32:49of conventional dendritic cells.
32:52The two canonical subset, CBC
32:55one and CBC two, but
32:56also a third subset
32:58that has been
33:01described
33:02as
33:02as in the glycol CCL
33:04seven high DC, but basically,
33:06a subset that share characteristic
33:08of CDC one and CDC
33:10two is very high in
33:12expression of CCL seven,
33:14and it has both
33:16activation markers, some immunomodulatory
33:21molecules,
33:22and,
33:23importantly,
33:25is actually very high in
33:26expression
33:28of
33:29the, IL fifteen and IL
33:32fifteen receptor alpha. So,
33:34can transpose
33:35IL fifteen to T cells.
33:37And in fact,
33:39we we found that
33:41the,
33:43this particular subset is the
33:45one that is increasing mice
33:47that are treated with radiation
33:49and m I one. And
33:50actually, the increases
33:52seems to be driven,
33:53by by blocking sulfalfa,
33:57specifically.
33:58And why is this important?
34:00Because it has been actually
34:02described as critical,
34:05for
34:06the for activation of CD80
34:09cells and the functionality
34:11in the tumor microenvironment
34:13exactly because it can transpose
34:15and,
34:17the IL fifteen
34:18to CD eighty cells. And
34:19so we are currently
34:22really exploring,
34:23in more details
34:25how this
34:26combination works, but
34:28our
34:29sort of
34:30data suggests that actually is
34:32really rewiring by blockages of
34:34alpha. We really rewire the
34:37the the this substance of
34:37dendritic cells to be more
34:39activated than regulatory.
34:42And, again, this is a
34:44work in process, but I
34:45think a very interesting,
34:49agent to pursue and there
34:50are some of these antibody
34:52in clinical trial. But
34:54I I wanna
34:55then go to to what
34:57are actually
34:59the negative
35:00effect of radiation
35:02that can,
35:03hinder,
35:05imbalance out the positive one
35:07and we have focused,
35:09quite a bit on the
35:11adenosine
35:12pathway.
35:13And this is because when
35:15you irrigate
35:17cancer cells,
35:20they do
35:21produce the increase,
35:23release HP, which is very
35:25pro inflammatory
35:27as well as they can
35:28actually release in the extracellular,
35:31environment,
35:32SIGAMP,
35:33and in AD plus. All
35:35of these nucleotide
35:36can be very pro inflammatory
35:38and
35:39many immune cells have a
35:40receptor
35:41and get become activated when
35:44exposed to,
35:46to the, actually,
35:49in SIGAMP, obviously.
35:51But
35:53there are a a family
35:54of actonuclear telases
35:56that can convert,
35:59the, NAD plus is converted
36:01by CD thirty eight in
36:02the blood cells that then
36:03is converted by EMPP one
36:06into AMP.
36:07And SIGAMP is also converted
36:09by EMPP one to AMP.
36:11And AMP
36:12is converted to adenosine by
36:14CD seventy three. And so
36:16these are is a very
36:17important system in the body
36:19that regulates
36:21in in in tissues,
36:22suppresses inflammation,
36:24and and
36:26the, immune cells also all
36:28have
36:29the subtle
36:30for, the for the adenosine.
36:34And there are two main
36:34receptor, the a two a
36:36and the HOB receptor. The
36:38HOA is expressed by T
36:39cells and by most cells.
36:40The HOB is most restricted
36:43to the mono
36:44monocytes and
36:46the the myeloid compartment, but
36:48it's also expressed on many
36:49cancer cells. And in cancer
36:51cells, it tends to actually
36:53promote
36:55DNA,
36:56repair, and so it can
36:57be a mechanism
36:59of resistance
37:01to, to DNA damaging agents.
37:04And the one important difference
37:07is the a to a
37:08receptor is activated by is
37:11higher affinity is activated by
37:13lower concentration
37:14of adenosine y d a
37:15to b,
37:16requires higher concentration, but that's
37:18what you can find actually
37:20in a tumor, particularly
37:21in the radiated tumor. And
37:23this is what we actually
37:24found
37:25when we did,
37:26look into,
37:28disease in mice model. We
37:29also did some experiment with
37:31human,
37:32cells,
37:34and and found that actually
37:36when you irradiate the cancer
37:37cells, they increase the spllection
37:39of CD seventy three, of
37:41CD thirty eight and EMPP
37:43one. So all these actonucleotidases.
37:45And, most importantly,
37:47in addition, those dependent, there
37:49is an increase in adenosine
37:51in the tumor. It's kind
37:52of tough measuring adenosine because
37:54it's a short lived metabolite,
37:56but we were able to
37:57actually,
37:58to see that.
37:59And and in fact, when
38:00you
38:02treat mice
38:04with the radiation and block
38:06c d seventy three, so
38:07block the adenosine, the sort
38:09of final step in adenosine
38:10generation, the stream of all
38:12these other
38:13pathways,
38:14you do get a multi
38:16improvement
38:17in the tumor control.
38:19This is radiation alone, and
38:21this is when you block
38:22CD seventy three. While CD
38:23seventy three by itself has
38:25no effect, and many of
38:26these mice actually went on
38:28to have long term survival
38:29and an an anemory response
38:31in the tumor microenvironment.
38:33If you block c v
38:34seventy three, in combination with
38:36radiation, you get an increase
38:38in dendritic cells. They are
38:39more activated. You have an
38:40increase in CD80 cells
38:42and an increase actually in
38:43the ratio of CD80 cells
38:45to regulatory T cells. So,
38:48it is a very important
38:50system,
38:51to that that really count
38:53as pluripotent
38:54effect of radiation.
38:56Now,
38:58adenosine
38:59signaling has been sort of
39:01reported,
39:02by Sidas and colleagues
39:04to be high in some
39:05tumors,
39:06particularly
39:07in renal cell cancer, but
39:09also very high in rectal
39:11and colorectal cancer.
39:13And another group,
39:16that shown
39:17shown similar data to what
39:18we had,
39:19that
39:20in in in a rectal
39:21cancer model in mice,
39:23showing that if you block
39:24c d seventy three, you
39:26improve response to radiation.
39:28The c d seventy three
39:29drives,
39:31increase is driven by irradiation
39:33on the cancer cells, and
39:34they even look at in
39:36patient that have received the,
39:38chemo radiation for rectal cancer.
39:41And in residual tumor, they
39:42found high levels of c
39:44d seventy three expression suggesting
39:46that maybe,
39:47it is actually a very
39:49important disease
39:52site. Well, this this could
39:53be really,
39:55a a block to to
39:57responses.
39:58And, we also use
40:00the organoids
40:01derived from colorectal cancer
40:04to test whether
40:06radiation would sort of increase
40:08the expression
40:09of the h b receptor.
40:12We found that indeed a
40:13two a receptor was poorly
40:14expressed and not affected by
40:16radiation, but the h b
40:18expression in this in this,
40:19tumors derived from from from
40:21patients
40:22was was high and was
40:24further significantly
40:25increased by radiation suggesting that
40:27potentially,
40:29radiation can also activate this
40:31resistant mechanism
40:33mediated by the HOB receptor,
40:35in this disease setting. And
40:37all, putting all of this
40:38together,
40:40it seemed to provide a
40:41strong rationale for actually testing
40:43adenosine receptor inhibition,
40:46in
40:47in in rectal cancer, a
40:49disease where, chemo radiation and
40:51radiation,
40:53by itself are routinely used
40:55in a standard of care
40:57treatment of patients.
40:58And this is the trial
41:00led by a very talented
41:02radiation oncologist at Cornell and
41:03CUSA Golden.
41:05Well, patients with rectal cancer
41:07receive
41:08the,
41:09the,
41:11atriumadent
41:12is
41:13the the inhibitors
41:14of both h a and
41:16to a h b receptor
41:17because we thought that's really
41:19important to inhibit both,
41:22given sort of the the
41:24the role that this, HOB
41:26can also play.
41:28And then, in combination with
41:30Shulko's addition therapy of five
41:32time five, then they go
41:34on to receive consolidation chemotherapy,
41:38in combination with anti PD
41:39one,
41:40antibody.
41:42And so there was a,
41:44vanillin safety trial where patient
41:46did not receive the anti
41:47PD one just to make
41:48sure that it was saved,
41:50the treatment
41:51proved to be to be
41:52saved.
41:54And there was actually one
41:56patient who showed a complete
41:57response that is durable for
41:59over a year,
42:00into partial responses, but the
42:02more interesting data, of course,
42:05in the in the,
42:07actually,
42:08sort of trial in the
42:10in the
42:11part two of the trial
42:12where,
42:13PD one is included.
42:16And this is designed as
42:17time to stage design.
42:20There are
42:22fifteen,
42:24sort of that that's,
42:26you know, if the responses
42:27are seen in the first
42:28fifteen patients,
42:29it will enroll up to
42:30twenty seven patients.
42:32To date, sixteen patients have
42:34been occluded,
42:35twelve
42:36are available for response. In
42:38rectal cancer, patient have the
42:40right to refuse surgery.
42:41If it seems by imaging
42:43and and and clinical evaluation
42:45that they have a complete
42:47response. In that case, response,
42:49is,
42:51is, you know, to to
42:52to be confirmed as complete
42:54response, you have to wait
42:55for one year and see
42:57that they don't recur.
42:59But to date, we have
43:00four patient that have a
43:02complete pathological
43:03response,
43:04five patient with complete clinical
43:06response, and see patient with
43:08partial,
43:09response,
43:10and for ongoing treatment.
43:12Now, so this is an
43:13example of a patient who,
43:16by imaging
43:17did not seem to have
43:18a complete response,
43:20and so underwent surgery. This
43:22is the pre treatment biopsy,
43:24and the surgery actually turned
43:26out there was just fibrosis
43:28amusing pool, so there was
43:29no viable cancer cells. So
43:31the patient is actually complete
43:33pathological responder.
43:35And so overall, this,
43:37is very encouraging
43:39particularly when compared to
43:41similar studies,
43:43that had tested different combination
43:45of
43:47radiation,
43:48chemotherapy,
43:49and immunotherapy,
43:51but of course, it's early
43:52on and we have to
43:53wait
43:54for
43:55for more,
43:56to for more data to
43:58confirm
43:59that this treatment is actually
44:02really
44:03superior to to to other
44:05regimen in this disease.
44:07We're also collecting a lot
44:08of specimen, so we'll be
44:10able to confirm whether the
44:12hypothesis that, you know, blocking
44:13adenosine signaling really makes a
44:15difference for the anti tumor
44:17immune response.
44:19We
44:20we we can definitely explore
44:21that hypothesis.
44:23But I think this is
44:24very
44:25encouraging
44:26and importantly,
44:27I think
44:28it
44:29suggests that in order for
44:32leveraging the ability of radiation
44:35to really make a difference
44:38in increasing responses to immunotherapy,
44:40we have to think
44:43of designing trials
44:45taking that have a very
44:46strong rationale.
44:49And,
44:51you know, we we we
44:52know that there are different
44:54dominant
44:55escape mechanism in different tumor
44:57types. So we have to
44:58keep that in mind,
45:00in terms of deciding what
45:01logitian can be combined with,
45:03and it's not just,
45:05of course,
45:06CTLA fall and and PG
45:08one agents
45:10and
45:11countering,
45:12also the negative effect that
45:14there there are there are,
45:16immunosuppressive
45:17effect that can be amplified
45:18and increased by radiation. And
45:20so we also have to
45:21keep that in mind.
45:23And, so I think,
45:25that this will
45:27lead to the design of
45:29more effective
45:30better trial, more effective combination
45:32treatment. A lot of work
45:33to do. And I just
45:35for those interested, this is
45:37a a paper that just
45:38came out in Lancet Oncology
45:40that is kind of summarizes
45:42a lot of discussion we
45:43had last year,
45:45with with the sort of,
45:47a lot of of people
45:49that have done seminal work
45:51in in radiation immunotherapy
45:52field in trying to figure
45:54out
45:55how,
45:56where do we go from
45:57here? How do we increase,
46:00knowledge in,
46:02we design better trial and
46:03we can make
46:05this work,
46:07much better.
46:08And I want to conclude
46:10by, of
46:12course, acknowledging,
46:13the many people that contributed
46:15to to the work.
46:18And I'm I showed you
46:20the picture of some of
46:21the post doc that did
46:22the, the work including Maude,
46:24Sharpen, Pierre. She's still in
46:26the lab.
46:27And many other postdoc went
46:29on to to,
46:30to their own independent position
46:32in different,
46:33places.
46:35And,
46:36of course, my, long term
46:37colleague, collaborator,
46:38and and Francilia Fomentu
46:40and,
46:42that that does,
46:44sort of,
46:45got me actually to to
46:46work on radiation in the
46:47first place,
46:49and many other collaborator,
46:52and, and our founding. And
46:54thank you very much for
46:55your attention, and I'll be
46:57happy to take questions.
47:04Yes.
47:09Great talk.
47:11You know, you've you've done
47:12a lot of really amazing
47:13work looking at the ability
47:14of radiation to stimulate human
47:15response,
47:16but I just wanted to
47:17start about the kind of
47:18other side of the coin.
47:20You know, what about the
47:20ability of radiation to kind
47:22of stop large tumors from
47:24inhibiting immune systems? So for
47:25example, if we have a
47:26large necrotic tumor, it's got
47:27hypoxia acidosis.
47:29We know that if t
47:30cells go in there, they
47:31stop functioning.
47:32And so, you know, and
47:34also with the clinical trials,
47:35with these trials, which already
47:36once that disease is largely
47:38negative Yeah. But the comprehensive
47:39relations have been largely positive.
47:41So I just wanna, you
47:41know, best of the set
47:42of point when you hear
47:43your thoughts on that. No.
47:44Sure. Of course. So,
47:46the group of University of
47:48Chicago, of course, Ludwig, Selbaum,
47:50with Jason and many others
47:52have done a lot of
47:53very nice work with multisite
47:55radiation with very large tumor.
47:58And I think it's definitely
48:01the the the good choice
48:03in in some disease setting.
48:05Ablation I mean, the bulking
48:07by itself could be beneficial
48:09and also reducing,
48:10you know, to to reduce
48:12systemic immunosuppression
48:13and we know
48:14from work by by John
48:16Wiley and others that PG
48:17one really has the best
48:19responses with lower tumor overall
48:21tumor burden. Right? So decreasing
48:23tumor burden could be very
48:25important. Also, it's important because,
48:28you are you know, we
48:29know there is
48:31heterogeneity between tumor side, advanced
48:33metastatic setting.
48:35I think there is a
48:36big role for,
48:38multisite,
48:40radiation therapy
48:42potential. You could also
48:44think of, you know,
48:47if you have disease heterogeneic,
48:49you may be able to
48:50vaccinate,
48:51you know, against different sets
48:53of antigens.
48:55But that said, I think
48:56it is really important to
48:58think what is the
49:02effect
49:03that you want to get
49:05from radiation
49:06when you think of a
49:08sort of clinical study.
49:09So it could be, you
49:11know, just a little bit
49:12of radiation to maybe
49:14increase permeability
49:15of tumor. There is some
49:17interesting work done with CAR
49:18T cells, but called the
49:20cell
49:21group that, you know, radiation
49:23may actually increase.
49:25In that case, you don't
49:26necessarily need to generate new
49:27T cells, but you are
49:28actually
49:30helping the functioning of the
49:31CAR T cells that are
49:32infused.
49:33And and that may require
49:35just low doses.
49:36There are some other very
49:38interesting effect of low dose,
49:39one that was just I
49:41think the paper just came
49:42out today in cancer cells
49:44from Lawrence,
49:45Ziv Mogale and with the
49:46Kramer where they see that
49:48very low doses to the
49:49intestine can actually with the
49:51line microbiota
49:52can,
49:53increase immune activation
49:55systemically.
49:56So it's another completely different
49:58angle. But then if you,
50:00you know, you again, you
50:01can the bulk or and
50:03maybe even prime responses with
50:06with ablative radiation
50:08to multisite.
50:09And then when you have
50:11most most likely in the
50:12early disease setting, in the
50:14adjuvant setting,
50:15you may
50:17leverage
50:18this ability of radiation to
50:19try to induce an inside
50:20of a scene. And I
50:22think that's now what we
50:23are moving more to, to
50:25to try to use it
50:26in a neurojoint setting. So,
50:28like, cancer, we have a
50:29trial in breast cancer,
50:31And I think, you know,
50:32the trial
50:34in lung cancer that was
50:35actually published by,
50:37Nassar Al Torky and and
50:38Sylvia Filmente where they did
50:40radiation and and, PEMBLO
50:43in early lung cancer.
50:45And so there is, I
50:47think, a different,
50:50you different ability of radiation
50:52to increase the
50:54to work well with the
50:55cancer immunotherapy,
50:57but we have to both
50:58choose
50:59the right radiation
51:00dose
51:01and and and delivery and,
51:03you know, sort
51:05of location where you wanna
51:06deliver it as well as
51:08think about what is the
51:09microenvironment
51:10and whether radiation can increase
51:12adenosine and that will inhibit
51:14the ability to plan an
51:15immune response or, you know,
51:17TGF beta, there are plenty
51:19of other mechanisms that maybe
51:21we can work with to
51:22improve this,
51:23this response.
51:25Yes. That was a wonderful
51:27talk.
51:28We could model
51:29model,
51:30how you've taken radiation oncology
51:32for.
51:33My question is, you know,
51:34you mentioned early disease and
51:35lung cancer, and certainly that
51:37would be in, marvelous places
51:38to use this. What about
51:39toxicity? You know, we worry
51:41about radiation pneumonitis.
51:42Right. And then, you know,
51:43we're we're sort of reactivating
51:45the immune system in this
51:46way. Have you seen more
51:47toxicity in your problems in
51:49your in your in your
51:49trials? Are they different mechanisms?
51:51How how's that working out?
51:53So in the trial that,
51:56NASA and Tolkie did,
51:59there was no real increased
52:01toxicity.
52:03And I think, of course,
52:04you had to to use
52:05radiation, you know, SBLT, very
52:07targeted light. That
52:10said, there is a, you
52:12know, an interesting observation,
52:15that that, was a,
52:18published,
52:19by by an investigator at
52:20Cornell.
52:24I'm so
52:26the name right now doesn't
52:27come to me, but well,
52:28they actually saw in a
52:29mouse model that there was
52:31a little bit of radiation,
52:34to
52:36to the lung. Normal lung
52:37would activate actually claps cells,
52:39and that activation was favoring
52:42the tumor rejection.
52:45So sometimes
52:46I think it was considering,
52:47of course, toxicity remains
52:50a very important concern.
52:52But looks like when people
52:54start looking at
52:56some of the effect of
52:57radiation on the normal tissue,
52:59it might have sometimes
53:02effects that could, you know,
53:03in unexpected
53:05way
53:06actually increase,
53:08immune responses.
53:09That said,
53:10of course, I think
53:12it's extremely important to keep
53:14the radiation as focused as
53:15possible to the tumor target.
53:17And maybe we can actually
53:20some recent evidence is is
53:22not my my work, but
53:23there is evidence from, Zachary
53:26Morris at,
53:27in Wisconsin, also from Eric
53:29Dorsch group
53:30in Paris that if you
53:32give non uniform radiation to
53:34the tumor,
53:35you may have a benefit.
53:37So which would suggest that
53:38maybe you don't have to
53:39radiate the entire tumor,
53:41so that would also allow
53:43people not to,
53:45you know, deliver potential
53:47toxicity when you are close
53:48to a very sensitive organ
53:50like the heart, right, or
53:51or something like that. And
53:53in in the trial,
53:54that by by
53:56University of Chicago when they
53:58did multisite radiation with the
53:59inter p g one in
54:00really advanced patients, but they
54:02saw that some tumors were
54:03so big they couldn't irradiate
54:05the entire tumor.
54:06But they saw that there
54:07was responses
54:08were similar to the tumor
54:10that received complete radiation, suggesting
54:12that maybe because you have
54:13an immunotherapy
54:14involved,
54:16it doesn't matter anymore as
54:17much
54:18to eradicate the entire tumor.
54:21I think this is not
54:22something that anybody will start
54:25implementing
54:26in the clinic, but something
54:27that maybe is is an
54:28error to to to really
54:30study
54:31because it could be really
54:32interesting to explore.
54:36Yes?
54:37The setting up the negative
54:39randomized trials, was that first
54:40patient just responding to ipilimumab?
54:43I mean, is how do
54:44you start to separate,
54:46the component of
54:48because I I haven't seen
54:49those studies, and it's it's,
54:51I understand you're trying to
54:52get the mechanism. But Yeah.
54:54But,
54:55but
54:56of course,
54:57you never know. Right?
54:59The only thing is that
55:01based on even there was
55:02a a I believe a
55:03phase three with chemo EP
55:05in lung cancer. They didn't
55:06show great responses.
55:09So based on but you
55:11don't know. That that could
55:12be that one patient that,
55:14of course, we
55:16can't rule it out.
55:18The only and and because
55:20we couldn't immunomonitor,
55:22we you know, it was
55:23not a trial.
55:25But in the trial, we
55:26really seen that there is
55:28the increase in T cells
55:30occurs, you know,
55:32after completing radiation now.
55:34We also saw that actually,
55:37neoantigen
55:38that was
55:39I guess we which we
55:41we saw T cells developing
55:43was in a in a
55:44gene that is increasing expression
55:47by radiation.
55:48I mean, we couldn't prove
55:49it happens in the patient,
55:50of course, but,
55:52you know, sort of if
55:53you evaluate tumors very similar
55:55was a KVAS,
55:57p fifty three deficient tumor
55:59when we evaluate this inorganoid
56:01that has a similar,
56:03sort of mutation profile. There
56:05was upregulation
56:06of of the gene.
56:09I've been actually
56:10we confirm a similar,
56:12effect in in the mouse
56:13model that the digestion can
56:15actually expose some mutation on
56:17the antigen just because it
56:18up regulates
56:19the expression of genes that
56:21are,
56:23in, you know, that are
56:24so mutation in, of course,
56:25DNA lethal genes are very
56:27frequent. And and when you
56:29have, you know, DNA damage
56:30and stress response, you up
56:31regulate a lot of genes.
56:34We actually did look at
56:35a lot of such work
56:37in,
56:39in in different,
56:41in in different cell line
56:42and and organoids, and there
56:43is huge transcriptional response after
56:46a dish. That's sad.
56:48We cannot do it. There
56:49is no way we prove
56:50it. And I agree.