LICENSE AGREEMENT

<PAGE>

                                                                Exhibit 10.3.2.1

          Confidential Materials omitted and filed separately with the
        Securities and Exchange Commission. Asterisks denote omissions.


                                 LICENSE AGREEMENT

     Effective May 31, 2001, (the "Effective Date"), Research Corporation
Technologies, Inc., a Delaware nonprofit corporation, with offices at 101 N.
Wilmot Road, Suite 600, Tucson, AZ USA 85711-3365 ("RCT"), and BioVex Ltd., a
corporation organized under the laws of the United Kingdom, with offices at The
Windeyer Institute, 46 Cleveland St., London W1T 4JF, England ("Licensee"),
agree as follows (fully-capitalized terms are defined in ARTICLE VIII):

                                     ARTICLE I
                                     LICENSE

     SECTION 1.1. Grant of License. RCT hereby grants to Licensee a nonexclusive
license under the LICENSED PATENTS in the LICENSED FIELD to make and have made
LICENSED PRODUCTS, to USE LICENSED PRODUCTS, to SELL LICENSED PRODUCTS, to offer
to SELL LICENSED PRODUCTS, and to import LICENSED PRODUCTS, free from suit by
RCT for infringement of the PATENT CLAIMS in the LICENSED FIELD in all countries
of the world in which RCT has LICENSED PATENTS. Licensee covenants and agrees
that its activities under this Agreement shall be limited to activities in the
LICENSED FIELD above. Any right granted above to SELL or offer to SELL is
restricted in that Licensee may only SELL or offer to SELL LICENSED PRODUCTS to
health care professionals, those distributing to health care professionals, and
health maintenance organizations that intend and agree to use such LICENSED
PRODUCT in the LICENSED FIELD. Licensee covenants that its activities under this
Agreement shall be so limited. No license or rights are granted or implied under
any patent application or patent not a LICENSED PATENT. Except as provided in
SECTION 1.2, Licensee shall have neither the right nor the power to grant any
sublicenses. Licensee shall have no right or license to make, USE, SELL, offer
to SELL, or import any CLAIMED DNA or CLAIMED CELL intended or suitable for the
ex vivo production of proteins or polypeptides (which, for the avoidance of
doubt, does not include ex vivo gene therapy), or for use in transgenic animals.

     SECTION 1.2. Extensions to AFFILIATES.

          Subsection 1.2.1. Grant of Right. RCT hereby grants to Licensee the
right to extend to Licensee's AFFILIATES the license granted under SECTION 1.1
of this Agreement. Licensee shall notify RCT in writing before any extension to
an AFFILIATE is made. If an AFFILIATE ceases to be an AFFILIATE, any license
extended to such AFFILIATE under this Subsection shall terminate concurrently
with such AFFILIATE's ceasing to be an AFFILIATE.

          Subsection 1.2.2. Licensee Responsible for Performance. Licensee shall
be responsible for the performance of its AFFILIATES to which it extends this
license. For assessing, reporting and paying earned royalties under this
Agreement, the manufacture, SALE, offer for SALE, USE (including R&D USES) or
importation of LICENSED PRODUCTS by Licensee's AFFILIATES shall be considered
the manufacture, SALE, offer for SALE, USE, or importation of such LICENSED
PRODUCT by Licensee.

                                                                     May 31, 2001


                                        1

<PAGE>

          License Agreement between RCT' and BioVex Ltd.;
          RCT Project No. 213-1734; Rottman [Gene Therapy]

          Subsection 1.2.3. Reports and Payments. Each AFFILIATE may make the
pertinent reports and royalty payments specified in ARTICLE II ("Financial
Terms") directly to RCT on behalf of Licensee, if Licensee provides RCT prior
written notice. Otherwise, Licensee shall make such payments and reports
separately showing the AFFILIATE's USE, SALE, and importation of LICENSED
PRODUCTS.

     SECTION 1.3. RCT's Obligations to Offer Licenses. Licensee may desire to
have LICENSED PRODUCTS, that have been introduced into human beings in the
course of clinical trials conducted under the sponsorship or direction of
Licensee, marketed and SOLD by a commercial partner, co-promoter or developer (a
"Qualified License Prospect"). From time to time, Licensee may provide to RCT a
written request that RCT grant a license under the LICENSED PATENTS to such
Qualified License Prospect. Promptly after receiving each such written request,
RCT shall offer to the pertinent Qualified License Prospect a license under the
LICENSED PATENTS: (a) at the same earned royalty rate and the annual minimum
royalty payment amounts provided in this Agreement; and (b) as to other
financial terms, at the then-prevailing terms offered by RCT to others for such
a license. RCT shall negotiate each such license in good faith but shall not
have any obligation to enter into such license if RCT and the pertinent
Qualified License Prospect are unable to agree upon the terms of such license.

     SECTION 1.4. No Further Rights. Except as expressly provided in this
ARTICLE I, no further or different license or right is granted or implied.

                                   ARTICLE II
                                 FINANCIAL TERMS

     SECTION 2.1. License Fees.

          Subsection 2.1.1. License Issue Fee. On or before the date thirty days
after the execution and delivery of this Agreement, Licensee shall pay to RCT a
non-refundable, non-creditable license issue fee of US$[**].

          Subsection 2.1.2. License Maintenance Fee. Licensee shall pay to RCT a
non-refundable, non-creditable annual license maintenance fee. In recognition of
the date on which this Agreement is signed, the first annual maintenance fee
shall be US$[**] due on or before March 30, 2002. Subsequent annual maintenance
fees shall be US$[**] and shall be paid on or before every January 30 occurring
after the year 2002 during the term of this Agreement and before the January 30
on which the annual minimum royalty payments under SECTION 2.3 are first made.

     SECTION 2.2. Earned Royalties.

          Subsection 2.2.1. Accrual, Amount, and Payment. Licensee shall pay to
RCT earned royalties of [**]% of the NET SALES VALUE of each LICENSED PRODUCT
USED or SOLD by or for Licensee or its AFFILIATES during the term of this
Agreement. Licensee shall also pay to RCT earned royalties of [**]% of the NET
SALES VALUE of each LICENSED PRODUCT made or imported by or for Licensee or its
AFFILIATES during the term of this Agreement but USED or SOLD after the term of
this Agreement.


                                         2

<PAGE>

          License Agreement between RCT' and BioVex Ltd.;
          RCT Project No. 213-1734; Rottman [Gene Therapy]

          Subsection 2.2.2. One Royalty. Only one earned royalty will accrue and
be paid on a given LICENSED PRODUCT, even if such LICENSED PRODUCT is SOLD or
transferred between RELATED PARTIES for subsequent USE or RESALE, or if the
manufacture of such LICENSED PRODUCT in one country is covered by the LICENSED
PATENTS and the USE, SALE, or importation in another country is covered by the
LICENSED PATENTS.

          Subsection 2.2.3. Transactions with Other Licensees. If Licensee SELLS
a LICENSED PRODUCT to a third party under circumstances where such third party
will RESELL such LICENSED PRODUCT and where such third party has a license under
the LICENSED PATENTS to make, USE, SELL, offer to SELL, or import LICENSED
PRODUCTS (a "third-party licensee"), the earned royalty on such SALE shall
accrue and be paid with respect to such third-party licensee's RESALE of such
LICENSED PRODUCT under such third-party licensee's license. If Licensee
purchases a LICENSED PRODUCT from a third-party licensee for RESALE by Licensee,
the earned royalty on such SALE shall accrue and be paid with respect to
Licensee's RESALE of such LICENSED PRODUCT under this Agreement.

          Subsection 2.2.4. Taxes. Licensee shall bear all taxes and charges
assessed or imposed by a governmental authority, including withholding taxes
imposed on payments under this Agreement (collectively, "Non-deductible Taxes").
However, Licensee shall have no accountability for any income tax imposed on RCT
by the United States (or other country) or a political or governmental
subdivision thereof, or for any maintenance fees or annuity payments for keeping
any LICENSED PATENT in force. In addition, Licensee may, in determining NET
SALES VALUE, deduct taxes or duties imposed on SALES of LICENSED PRODUCT and
expressly permitted as deductions under this Agreement. All payments hereunder
shall be made undiminished by any Non-deductible Tax. Licensee shall cooperate
with and assist RCT in obtaining any exemption from Non-deductible Taxes imposed
by any government (or instrumentality) on royalty payments made by Licensee to
RCT. If such an exemption is not available, the earned royalty rate provided
above shall be increased an amount such that the amount actually remitted to RCT
after Licensee withholds any Non-deductible Taxes is no less than the above
percentage of the NET SALES VALUE of such LICENSED PRODUCTS. If the earned
royalty rate is grossed up in the foregoing manner, Licensee may retain any
refund of Non-deductible Taxes and RCT shall reasonably cooperate with Licensee
in obtaining, through ordinary administrative procedures, such refund without
out-of-pocket expense to RCT.

     SECTION 2.3. Annual Minimum Royalties.

          Subsection 2.3.1. Amount and Payment Date. Licensee shall pay to RCT a
prepaid, non-refundable annual minimum royalty of $[**]. The first annual
minimum royalty payment is due on or before the January 30 immediately following
the date of first SALE of a LICENSED PRODUCT. Subsequent annual minimum royalty
payments shall be payable on each successive January 30 on which this Agreement
is in effect. Licensee's payment of the annual minimum royalty for each calendar
year shall accompany Licensee's report to RCT for the last quarter of the
immediately preceding calendar year.

          Subsection 2.3.2. Credits. Licensee may credit the annual minimum
royalty payment actually made in a given calendar year only against the amount
of the earned royalties


                                        3

<PAGE>

          License Agreement between RCT' and BioVex Ltd.;
          RCT Project No. 213-1734; Rottman [Gene Therapy]

payable by Licensee to RCT for Licensee's activities in the same calendar year.
Licensee may not credit any earned royalties paid for any calendar year that
exceed the annual minimum royalties paid in that calendar year against any
annual minimum royalty payment due in any other calendar year.

     SECTION 2.4. Periodic Reports and Payments.

          Subsection 2.4.1. Frequency of Reports. On or before each January 30
occurring before the first SALE of a LICENSED PRODUCT under this Agreement,
Licensee shall deliver to RCT a true and accurate report showing the items
specified in Subsection 2.4.3 below as they pertain to the calendar year just
ended. On or before the first January 30, April 30, July 30 or October 30
immediately following the first SALE of a LICENSED PRODUCT under this Agreement
and on or before each January 30, April 30, July 30 and October 30 thereafter
during the term of this Agreement, Licensee shall deliver to RCT a true and
complete written report showing the items specified in Subsection 2.4.3 below as
they pertain to the calendar quarter just ended. Licensee's payment of the
earned royalties based on Licensee's or its AFFILIATES' activities in the
calendar quarter covered by the written report shall accompany the report. If no
earned royalties are due, Licensee shall so report. Licensee shall pay all
amounts due to RCT under this Agreement in United States currency collectible at
par (without deduction of exchange, collection or other charges) by wire
transfer to: RESEARCH CORPORATION TECHNOLOGIES, INC., Wells Fargo Bank, N.A.,
Tucson Main Office, 150 N. Stone Ave., P.O. Box 1871, Tucson, AZ 85702, ABA &
Transit No. 121000248, Acct. 4159-527159--RCT CHECKING; or to the account of RCT
at such other bank as RCT may from time to time designate in writing. Licensee
shall pay the cost of any wire transfer fees. If the amount is less than
$100,000, Licensee may elect to pay by company check, instead of wire transfer,
at the address shown in SECTION 7.2. On or before the date 90 days after the end
of the calendar quarter in which this Agreement is terminated, Licensee shall
provide to RCT a written report that complies in all respects with this SECTION
2.4. Licensee shall require each AFFILIATE to which this Agreement is extended
under SECTION 1.3 to make appropriate reports to Licensee to enable Licensee to
comply with this SECTION 2.4.

          Subsection 2.4.2. Certification. A responsible financial officer of
Licensee (or that officer's responsible designee), Licensee's independent
accounting firm, or the head of Licensee's internal audit committee shall
certify in writing that each such report is correct and complete.

          Subsection 2.4.3. Content of Quarterly Reports. Each report shall
provide the following information as its pertains to the preceding calendar
quarter just ended:

               (a) the quantities of LICENSED PRODUCTS billed by Licensee or its
          AFFILIATES during the previous calendar quarter in each country in
          which such billing occurred (separately stated for each entity and
           each country); and

               (b) the United States dollar value of the billings on such
          quantities in (a) above;


                                        4

<PAGE>

          License Agreement between RCT' and BioVex Ltd.;
          RCT Project No. 213-1734; Rottman [Gene Therapy]

               (c) the computation of the NET SALES VALUE based on the dollar
          value determined in (b) above including a detailed accounting of any
          allowed deductions from the invoice amounts to arrive at the NET SALES
          VALUE;

               (d) the computation of earned royalties based on the NET SALES
          VALUE computed under Paragraph (c) above;

               (e) a detailed accounting of any credits against earned royalties
          permitted under SECTION 2.3.

     SECTION 2.5. Books and Records. Licensee shall keep complete and accurate
books and reasonable supporting documentation to determine the accuracy of the
items reported under SECTION 2.4 and Licensee's compliance in other respects
with this Agreement. Licensee shall keep such books and documentation at its
principal place of business for five years following the end of the calendar
year to which they pertain (and access shall not be denied thereafter if
reasonably available). RCT may retain an independent certified public
accountant, reasonably acceptable to Licensee, to inspect, during reasonable
business hours, and copy such books and documentation to verify Licensee's
earned royalty statements or Licensee's compliance in other respects with this
Agreement. RCT shall provide Licensee with 30 days' written notice before any
such inspection is conducted. RCT shall not undertake such inspection more than
once per calendar year. If any such inspection discloses an underpayment of
earned royalties of 5% or more of the amount of royalties actually due for any
quarterly period, then Licensee shall promptly pay the reasonable cost of such
inspection after Licensee's receipt of the bill/invoice for such inspection.
Licensee shall require its AFFILIATES to keep such books and documentation to
enable Licensee to comply with this SECTION 2.5.

     SECTION 2.6. Sales Outside The U.S. If Licensee or an AFFILIATE SELL any
LICENSED PRODUCTS for currency other than United States currency, Licensee shall
determine the earned royalty payable for such LICENSED PRODUCT in such currency
and then convert the earned royalty into its equivalent in United States
currency at the New York foreign exchange selling rate for such currency for the
last business day of the calendar quarter for which payment is made, as
published by the Wall Street Journal. If such rate is not so published, the
conversion shall be at the selling rate for such currency for the last business
day of the calendar quarter for which payment is made, as published by a leading
New York, New York bank chosen by Licensee and reasonably acceptable to RCT. If
Licensee is late in making any payment, the applicable exchange rate obtained
from the sources described above shall be the greater of the rate on the date
payment was actually made or the rate on the date on which payment was due.

     SECTION 2.7. Late Payment.

          Subsection 2.7.1. Late Fees. Licensee hereby acknowledges that late
payment by Licensee to RCT of sums due under this Agreement will cause RCT to
incur certain costs including additional costs for legal, accounting and other
professional services to manage and administer this Agreement, the exact amount
of which will be extremely difficult to ascertain. Accordingly, if Licensee
fails to make any payment required under this Agreement on or before the date
ten days after Licensee's receipt of RCT's written notice of such failure, in
addition to


                                        5

<PAGE>

           License Agreement between RCT' and BioVex Ltd.;
          RCT Project No. 213-1734; Rottman [Gene Therapy]

any other remedy available under this Agreement and any remedy available at law
or equity, Licensee shall pay to RCT a late payment fee equal to the lesser of
$5,000 or 5% of such overdue amount (in addition to any interest charges
required or permitted below). The parties hereby agree that such late charge
represents a fair, reasonable and administratively simple estimate, at the time
of execution of this Agreement, of the costs RCT will incur by reason of
Licensee's late payment.

          Subsection 2.7.2. Interest Charges. If Licensee fails to make any
payment required under this Agreement on or before the date ten days after
Licensee's receipt of RCT's written notice of such failure, Licensee shall pay
interest on the unpaid portion of such amount at an annual rate equal to the
prime rate, as quoted by the Wells Fargo Bank, N.A., plus 5%, which shall accrue
from the date the payment not timely made became due until the date such payment
is paid in full. The interest shall be compounded on the last day of each
calendar quarter. If such rate exceeds the rate allowed by applicable law, then
the highest rate allowed by law shall apply.

          Subsection 2.7.3. Application of Payments. Any payments received shall
be applied first to any late charges, second to the satisfaction of any unpaid,
accrued interest and finally to the satisfaction of any unpaid principal.

                                    ARTICLE III
                                   [RESERVED]

                                   ARTICLE IV
                                LICENSED PATENTS

     At its sole cost and expense, RCT shall maintain the LICENSED PATENTS,
although RCT may, in its sole discretion, abandon any LICENSED PATENT. If RCT
abandons any LICENSED PATENT, RCT shall promptly provide to Licensee written
notification of such fact.

                                    ARTICLE V
                                  INFRINGEMENT

      RCT will protect the LICENSED PATENTS from infringement and prosecute
alleged infringers when, in its sole judgment, such action may be necessary,
proper, and justified. Licensee shall, as RCT may request, fully cooperate with
RCT, at no out-of-pocket expense to Licensee, in connection with any such
action.

                                   ARTICLE VI
                                   TERMINATION

     SECTION 6.1. Automatic Termination. The term of this Agreement shall expire
on the TERMINATION DATE unless sooner termin