COLLABORATION AGREEMENT

* Portions denoted with an asterisk have been omitted and filed separately with

the Securities and Exchange Commission pursuant to a request for confidential

treatment.

COLLABORATION AGREEMENT

This Collaboration Agreement (this "Agreement"), made as of July 1, 2004

(the "Effective Date"), is by and between Advanced Cardiovascular Systems, Inc.,

a corporation organized under the laws of California and having a place of

business at 3200 Lakeside Drive, Santa Clara, California 95054 (herein referred

to as "ACS"), and Miravant Medical Technologies, together with its subsidiary,

Miravant Cardiovascular, Inc., both corporations organized under the laws of

Delaware and having places of business at 336 Bollay Drive, Santa Barbara,

California 93117 (collectively referred to as "MMT"). ACS and MMT may each be

referred to as a "Party" or, collectively, as the "Parties" in this Agreement.

RECITALS

WHEREAS, ACS is engaged in the design, development, manufacture and

commercialization of medical devices for the diagnosis and treatment of

cardiovascular diseases, and ACS has patented and other proprietary medical

devices and systems for delivery of therapeutic compositions and drugs to

patients;

WHEREAS, MMT is developing photodynamic therapy ("PDT") products using

light activated compositions or drugs and related devices or systems for the

treatment of diseases, such as ophthalmology, dermatology, cardiovascular,

oncology and other conditions and diseases;

WHEREAS, the Parties wish to enter into a business alliance in which they

will collaborate on the development, pre-clinical and clinical investigations of

certain light activated compositions or drugs and related devices or systems for

use in the treatment of cardiovascular diseases, all on the terms and conditions

set forth below; and

WHEREAS, contemporaneously with the execution and delivery of this

Agreement, the Parties are executing and delivering a Securities Purchase

Agreement and a Registration Rights Agreement pursuant to which ACS has agreed

purchase certain MMT preferred stock and to provide certain registration rights

under the Securities Act, the rules and regulations promulgated thereunder and

applicable state securities laws.

AGREEMENT

NOW, THEREFORE, in consideration of the covenants and obligations expressed

herein, and intending to be legally bound, the Parties agree as follows:

ARTICLE 1: DEFINITIONS

1.1 "ACS Indemnitees" has the meaning ascribed to it in Section 11.1.

1.2 "ACS Inventions" has the meaning ascribed to it in Section 9.2.

1.3 "Affiliate" means, with respect to any Party, any corporation or other

business entity, which controls, is controlled by, or is under common control

with such Party. A corporation or other entity shall be regarded as in control

of another corporation or entity if it owns or directly or indirectly controls

at least fifty percent (50%) of the voting stock or other ownership interest of

the other corporation or entity (or alternatively, if not meeting the preceding

and with respect to foreign entities, if it owns the maximum such ownership

interest permitted by law), or if it possesses, directly or indirectly, the

power to direct or cause the direction of the management and policies of the

corporation or other entity or the power to elect or appoint at least fifty

percent (50%) of the members of the governing body of the corporation or other

entity.

1.4 "Agreement" has the meaning ascribed to it in the preamble hereof.

1.5 "Confidential Information" means all proprietary, non-public

information that has commercial value or other utility in a Party's business,

including but not limited to any information, inventions, know-how, biological

materials, chemical compounds, data, pre-clinical data, and materials provided

by one Party to the other pursuant to this Agreement, whether existing or

disclosed in oral, written, graphic, digital, optical, electronic or other form.

1.6 "Effective Date" has the meaning ascribed to it in the preamble hereof.

1.7 "FDA" means the United States Food and Drug Administration and any

successor agency thereto.

1.8 "INDA" means (a) an Investigational New Drug Application, as defined in

the United States Federal Food, Drug and Cosmetic Act, as amended, and the

regulations promulgated thereunder, that is required to be filed with the FDA

before beginning clinical testing of human subjects, or any successor

application or procedure, (b) any foreign counterpart of a United States

Investigational New Drug Application, and (c) all supplements and amendments,

including supplemental Investigational New Drug Applications and related foreign

counterparts, that may be filed with respect to the foregoing.

1.9 "Intellectual Property" means all of the following or their substantial

equivalents or counterparts in any jurisdiction throughout the world: (i)

patents, patent applications and invention disclosures, (ii) trademarks, service

marks, trade dress, trade names, corporate names, logos and Internet domain

names, (iii) copyrights, software and source code and copyrightable works, (iv)

registrations and applications for any registration for any of the foregoing and

(v) trade secrets, know-how, confidential information and inventions.

1.10 "Joint Inventions" has the meaning ascribed to it in Section 9.2.

1.11 "JSC" has the meaning ascribed to it in Section 2.1.

1.12 "Lead Drug" means that certain MMT compound designated as MV0633, or

such other PDT Drug, as the Parties may mutually agree to in writing.

1.13 "MMT Indemnitees" has the meaning ascribed to it in Section 11.2.

1.14 "MMT Inventions" has the meaning ascribed to it in Section 9.2.

1.15 "PDT" has the meaning ascribed to it in the recitals hereof.

1.16 "PDT Device" means those certain non-thermal medical laser devices,

including catheters, that have light sources of any wavelength and associated

equipment designed by MMT to activate the Lead Drug or PDT Drug for the

treatment of cardiovascular disease in the Therapeutic Field.

1.17 "PDT Drug" means those certain light activated compositions or drugs

that are designated as MV0633 and MV0611, including compounds and derivatives of

these compounds that have been, are being, or will be evaluated during the term

of this Agreement by MMT for the treatment of patients within the Therapeutic

Field or that are being developed by MMT during the Term and activated with a

PDT Device for the treatment of patients within the Therapeutic Field. For

clarity, the MMT compound designated as SnET2 is not a PDT Drug under this

Agreement.

1.18 "PDT Technology" means existing and future technology owned or

controlled by MMT that is specifically directed to treating cardiovascular

indications within the Therapeutic Field and necessary for the manufacture, use

or sale of PDT Drug, PDT Device or PDT Therapy, including, without limitation,

materials and processes utilized in production or processing of such PDT Drug,

PDT Device or PDT Therapy, and trade secret information or know-how relating to

such materials and processes.

1.19 "PDT Therapy" means a PDT Drug, its related delivery product or

system, and its related light activation product or system that are owned or

controlled by MMT and used for the treatment of a patient within the Therapeutic

Field.

1.20 "Party" and/or "Parties" has the meaning ascribed to it in the

preamble hereof.

1.21 "Patent Prosecution" has the meaning ascribed to it in Section 9.3.

1.22 "Patent Rights" means all existing patents and patent applications and

all patent applications disclosing or claiming any Lead Drug, PDT Drug, PDT

Device or PDT Therapy conceived by a Party during the Term, including any

continuations, continuations-in-part, divisions, provisionals or any substitute

applications, any patent issued with respect to any such patent applications,

any reissue, reexamination, renewal or extension (including any supplemental

patent certificate) of any such patent, and any confirmation patent or

registration patent or patent of addition based on any such patent, and all

foreign counterparts of any of the foregoing.

1.23 "Phase I Trial" means a complete program of one or more human

clinical trials in the United States wherein such program is intended to

initially evaluate the safety and/or pharmacological effect of, or otherwise to

satisfy the requirements of 21 ss.CFR 312.21(a), with respect to a Lead Drug,

PDT Drug, PDT Device or PDT Therapy for a particular condition in patients under

study within the Therapeutic Field.

1.24 "Phase II Trial" means a complete program of one or more human

clinical trials in the United States wherein such program is intended to

initially evaluate the appropriate dose of a drug for effectiveness of, or

otherwise satisfy the requirements of 21 CFR ss.312.21(b), with respect to a

Lead Drug, PDT Drug, PDT Device or PDT Therapy for a particular condition in

patients under study within the Therapeutic Field.

1.25 "Pre-Clinical Development Program" means the collection of

pre-clinical development activities including, without limitation, conducting

all animal studies, good laboratory practices (GLP) animal studies, or other

studies and gathering all data required with respect to non-safety research

studies, early stage drug development, drug metabolism, mechanism of action

analyses, pharmacokinetics, potency, selectivity, safety/toxicology and

manufacturing scale up, which are to be conducted by MMT as it deems necessary

with input from the JSC in order to file an INDA submission with the FDA for a

Lead Drug, PDT Drug, PDT Device or PDT Therapy in the Therapeutic Field.

1.26 "Term" has the meaning ascribed to it in Section 12.1.

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1.27 "Therapeutic Field" means the use of a Lead Drug, PDT Drug, PDT

Device or PDT Therapy for PDT treatment of human cardiovascular diseases

including but not limited to treatment of atherosclerotic vascular disease and

prevention of restenosis as well as other cardiovascular diseases or indications

designated by mutual written agreement of MMT and ACS from time to time in

accordance with the terms of this Agreement. Notwithstanding the foregoing,

Therapeutic Field shall not in any case include hemodialysis graft applications,

arterio-venous access disease, or diseases requiring local (non-intravenous)

SnET2 PDT drug delivery.

1.28 "Third Party" means a person or party other than ACS and MMT.

ARTICLE 2: JOINT COMMITTEE

2.1 Joint Steering Committee. Promptly following the Effective Date,

the Parties shall establish a Joint Steering Committee ("JSC") for the purposes

of collaborating on the development of MMT's Lead Drug, PDT Drug, PDT Device or

PDT Therapy within the Therapeutic Field pursuant to the preliminary development

plan that is attached to this Agreement as Exhibit A, in the manner and to the

extent provided herein. The JSC will be staffed by ACS and MMT employee

appointees, and the total number of JSC members will be eight (8), with four (4)

appointees for each Party, but the number may be adjusted upward or downward by

mutual agreement of the Parties. ACS initial JSC appointees will include one

business development manager, one new ventures research fellow, one new ventures

director and one clinical-regulatory research fellow. MMT's initial JSC

appointees will include one Endovascular Product Team Leader, one

Atherosclerosis Program Manager, one Cardiovascular Program Manager, and one

Director of Corporate Development & Strategic Planning. Either Party may replace

any of one or more of its appointees to the JSC at-will by giving written notice

thereof to the other Party.

2.2 Chairperson. The chairperson of the JSC shall be selected initially

by MMT from among the MMT employee appointees serving on the JSC and shall serve

in such role for one (1) year. After such one year period, the chairperson of

the JSC shall be selected from among the ACS employee appointees then serving on

the JSC, and that person will then serve in such role for one (1) year.

Thereafter, ACS and MMT shall alternate annually in selecting the chairperson of

the JSC from their respective appointees throughout the Term. The Chairperson of

the JSC will be responsible for calling and chairing meetings, developing

meeting agendas, and recording and distributing meeting minutes and directing

future actions of the JSC. The Chairperson of the JSC shall call one (1)

meeting, either face-to-face, video conference, or telephone conference, as

appropriate, for every calendar quarter during the Term or more frequently as

mutually agreed by the Parties.

2.3 Responsibilities of the Joint Steering Committee.

(a) In general, the responsibilities of the JSC will be to

analyze, consult, review and advise MMT, solely on a non-binding, advisory

basis, concerning the research, development, record keeping and other activities

related to any Lead Drug, PDT Drug, PDT Device, PDT Therapy or the Pre-Clinical

Development Program. As part of its responsibilities, the JSC will review and

make non-binding recommendations as necessary from time to time concerning MMT's

Pre-Clinical Development Program and Phase I Trial. Specific review and

consulting activities for JSC include, but are not limited to, (i) recommending

guidelines for staffing physician advisory groups, Pre-clinical Development

Program Plans, and Phase I Trial plans, (ii) discussing project projections,

budgets, tracking reports, and timelines, (iii) reviewing and discussing data

from pre-clinical studies and clinical trials, (iv) recommending additional

research studies beyond Pre-clinical Development Program Plans, (v) recommending

timing of and content for the INDA submission program with respect to any Lead

Drug, PDT Drug, PDT Device or PDT Therapy in the Therapeutic Field, (vi)

recommending content for the clinical readiness review, (vii) analysis of the

Phase I Trial Report, and (viii) recommending how to amend, as needed, the

Pre-clinical Development Program and Phase I Trial plans.

(b) The JSC shall have such other responsibilities as are

expressly set forth elsewhere in this Agreement or as are assigned to it as

mutually agreed upon by the Parties in writing.

(c) For clarity, MMT shall have the sole and exclusive right

to determine and control all research, development, commercialization and other

activities with respect to any Lead Drug, PDT Drug, PDT Device, PDT Therapy and

PDT Technology.

ARTICLE 3: MMT AND ACS OBLIGATIONS AND RESPONSIBILITIES

3.1 MMT Obligations and Responsibilities.

(a) MMT, through its Pre-Clinical Development Program, will

use commercially reasonable efforts to develop sufficient data concerning the

Lead Drug, PDT Drug, PDT Device, or PDT Therapy to enable MMT to file an INDA

submission with the FDA for such Lead Drug, PDT Drug, PDT Device, or PDT Therapy

in an expeditious and efficient manner.

(b) MMT agrees, in order for the JSC to undertake its

responsibilities, to provide the JSC with its information, data, records and

other documents including but not limited to MMT's comprehensive project plans

and tracking reports related to the Lead Drug, PDT Drug, PDT Device, PDT

Therapy, Pre-Clinical Development Program, and the Phase I Trial.

(c) MMT will use commercially reasonable efforts to i) provide

technical expertise concerning PDT Technology, ii) conduct its activities for

the Pre-Clinical Development Program and Phase I Trial, and (iii) provide data,

results and other related information generated in the course of the

Pre-Clinical Development Program and Phase I Trial to the JSC for review and

comment.

(d) MMT agrees to provide ACS with exclusive access to its

records reflecting inventions, ideas, information or data related to any Lead

Drug, PDT Drug, PDT Device, PDT Therapy or PDT Technology developed in the

course of work done under a Pre-Clinical Development Program and Phase I Trial

and to its records and data that existed prior to this Agreement related to any

PDT Drug. ACS acknowledges that MMT may share such records with its third party

contractors who are performing services for MMT in connection with the Phase I

Trial and who are under a confidentiality obligation with MMT without violating

the exclusive access granted to ACS herein. MMT also agrees to provide ACS with

written quarterly research and development updates as well as pre-clinical

research and clinical research updates in a format that is mutually agreed upon

by the Parties.

3.2 ACS Obligations and Responsibilities. ACS agrees, through its

appointees to the JSC, to (i) provide pre-clinical, clinical and regulatory

advice and consultation to MMT, (ii) offer its business and strategic

perspectives concerning treatment of atherosclerotic vascular disease, and (iii)

provide, in its sole discretion, reasonable advice and consultation concerning

catheter devices and systems for use in, or as used for, PDT Therapy.

ARTICLE 4: EXCLUSIVITY

4.1 Exclusive Collaboration Within The Therapeutic Field. Subject to

any obligations of the Parties herein, each Party agrees that it will not

commence a research, development, or commercialization plan or program, directly

or indirectly in collaboration with any Third Party, for the purpose of

researching, developing, delivering, administering, commercializing or otherwise

exploiting any Lead Drug, PDT Drug, PDT Device or PDT Therapy in the Therapeutic

Field during the Term, unless otherwise mutually agreed to by the Parties in

writing. The Parties acknowledge that this exclusivity obligation does not

prevent ACS or its Affiliates from making equity investments in, licensing or

acquiring PDT technology of any Third Party in the Therapeutic Field.

Notwithstanding the foregoing, MMT shall have the right to have any of the

activities under the Pre-Clinical Development Program and Phase I Trial

conducted on its behalf by Third Party contractors, and except as provided

herein nothing contained herein shall restrict either party's right to research,

discover, develop, manufacture and/or commercialize PDT products and technology

outside the Therapeutic Field.

ARTICLE 5: RIGHT OF FIRST REFUSAL

5.1 ACS's Right Of First Refusal. Upon (i) the completion of the Phase

I Trial as that event is defined in Section 12.1, or (ii) receipt by either

party of notice of termination of this Agreement pursuant to Section 12.2(a),

(b), (c) or (e), ACS shall have a right of first refusal ("ROFR") for a period

of 12 months to participate in any Phase II Trial. ACS participation may

include, but is not limited to, consultation regarding the design, manufacture

or use of light activation catheters or products, providing clinical and

regulatory consultation to MMT, providing funding to MMT for access to the Phase

II Trial data and results, or conducting the Phase II Trial in collaboration

with MMT or independently in the event that MMT would transfer or assign the

INDA to ACS, in each case as mutually agreed in writing by the Parties in

accordance with the process set forth in Section 5.1. ACS shall have thirty (30)

days to decide to exercise its ROFR after receiving written notice from MMT that

it has a bona-fide intention to begin, or that it has a bona-fide intention to

have a third party begin, any Phase II Trial. If ACS exercises its ROFR it shall

notify MMT in writing within such 30 day period. Then, the Parties will have an

additional thirty (30) days from the date of ACS's notice to MMT to exclusively

negotiate and enter into a term sheet concerning ACS participation in the Phase

II Trial. If the Parties execute a term sheet, they agree for a period of at

least sixty (60) days following the date of ACS's notice to MMT to negotiate in

good faith to reach a definitive agreement. In the event that MMT and ACS enter

into a definitive agreement, that agreement shall provide ACS with an option to

obtain a license from MMT to develop and commercialize, or otherwise exploit any

Lead Drug, PDT Drug, PDT Device or PDT Therapy within the Therapeutic Field on

terms to be mutually agreed upon by the Parties. If with respect to the subject

of a particular written notice received by ACS pursuant to this Section 5.1, the

Parties do not execute either the term sheet or the definitive agreement within

the foregoing time periods, then ACS's rights and MMT's obligations under this

Section 5.1 shall terminate, unless extended by mutual agreement or in the event

a delay is caused by the other Party's action or inaction, and MMT may proceed

with its plans for a Phase II Trial as set forth in the notice to ACS.

This Article 5 shall survive expiration or termination of this

Agreement except in the event of termination pursuant to Section 12.2(d) hereof.

ARTICLE 6: COSTS

6.1 Pre-Clinical Development Program and Phase I Trial Costs. All costs

and expenses related to research and development of PDT Therapy, MMT's

Pre-Clinical Development Program and Phase I Trial during the Term will be borne

by MMT.

ARTICLE 7: MMT RECORD KEEPING

7.1 Documentation. All tasks conducted by MMT in the course of its

performance under this Agreement shall be completely and accurately recorded,

recorded in reasonably sufficient detail and, where applicable, in good

scientific manner.

7.2 Policies for Maintaining Records. In order to protect the Parties'

Patent Rights under United States law in any inventions conceived or reduced

to practice during or as a result of any work performed by the Parties under

this Agreement, each Party agrees to require, consistent with its existing

policies, its employees to record and maintain all data and information

developed during this Agreement in such a manner as to enable the Parties to

use such records to establish the earliest date of invention and/or diligence

to reduction to practice. At a minimum, such individuals will record all

inventions generated by them in standard laboratory notebooks which are dated

and corroborated by non-inventors on a regular, contemporaneous basis.

ARTICLE 8: CONFIDENTIAL INFORMATION

8.1 Confidentiality Obligations. The Parties agree that, for the Term

and for three (3) years thereafter, either Party that receives Confidential

Information (a "Receiving Party") from the other Party (a "Disclosing Party")

shall keep completely confidential and shall not publish or otherwise disclose